H150F rebuild and enhancement - and everything else along the way (dropping the gearbox, doing the clutch, etc) (1 Viewer)

[DivByZero]

Now we're going to deviate from the FSM, because it's time for upgrades! I have on-hand a number of H150F boxes of different generations, as well as one fully torn down H151F I'm going to be raiding for parts. As I outlined in this post in another thread, the H150 and H151 are the same box essentially, other than the different gear ratios (represented by 0 and 1 respectively), and the fact that in the H151, triple piece syncros were fitted to first, second, and third gears, while the H150 only got them on second from 1992/08. We're going to rewrite history and change that here, building a H150 that has the original gear ratios for the H150 box, but with triple synchros on the first three gears. First, let's address the first gear. Here's first for the H150 on the right, and H151 on the left, with their corresponding synchros shown.

Now there are different gear ratios for first gear between the H150 and H151, so we can't just change over the gear assembly. As I go into detail about in the other thread though, these gear assemblies are made up of two halves - the gear itself, and the synchronizer cone, which is pressed onto the gear. They can be separated. The only difference between the two gears here apart from the synchronizer cone is the ratios. The cones are the same depth, and work with the identical hubs, sleeves, and output shaft. If we swap the cones over, we can use triple synchros on the H150 first gear, which is what we're gonna do.

Removing the cone from the H151 first gear is easy. The cone has three cutaways for the three piece ring to lock into. We can use a three jaw puller on those like this:

Separating the cone from the H150 first is harder. There are no cutaways to use, and as you can see below, there's not a lot of clearance from the edge of the teeth on the cone to the gear itself.

There's a maximum of about 2mm clearance. You could try and slip some sheet metal in there and press out with that, but I think it'd just deform. After trying a few things, including supporting the cone with ratchets on the press (which the sharp edge underneath just cut through), in the end the simplest method worked. I used a flathead screwdriver to pry around the edge, which managed to work the cone up little by little over 10 minutes or so. When I got enough clearance, I took it off the rest of the way using the three jaw puller under the (now raised) edge.

The two gears separated from their hub sleeves.

 

[DivByZero]

Before reassembly, it's time to do some cleanup. The splines where the cones join the gears will be full of old grease and slime, and in general we haven't done any cleanup so far. Give everything a good blast with degreaser and a thorough clean. After that, it's time to press the synchronizer cone from the H151 first gear onto the H150 first gear. Use some good quality multi purpose grease and put a thin covering on the splines of the gear and the cone, then press them together.

There we have it - a triple synchro H150 first gear! Wipe away the excess grease and it's good to go.

 

[DivByZero]

Third gear is much simpler, or much harder, depending on how you look at it. Here's the H151 third on the left with triple synchros, and the H150 version on the right with a single synchro:

Again, it's the same gear, just a different synchro hub pressed on. As you can see, there's almost no clearance here again. We could probably pry the hubs off with a screwdriver and get the three jaw puller in there, like we did for the H150 first gear, but it'd be harder, as we'd have to be careful not to put any pressure against the edges of the gear teeth. On the other hand, there's no need really, as the gears have the same ratio. After close inspection, I opted to just swap over the gear assembly entirely. Yes, the counter shaft has already "worn in" with the original gear, but honestly the gears are basically immaculate with barely any wear and virtually identical wear patterns, and if I was to replace a gear with a new one the counter gear would have to deal with that anyway. I decided it was better to avoid potential damage to the gears and just swap them rather than trying to pry this hub off the gear.

With that resolved, and the second gear already being a triple synchro on my H150, that gives me three piece synchro rings on the first three gears, which is what I was after.

 

[DivByZero]

It's now time to talk inspection and reassembly. First of all, I inspected the output shaft. I used my calipers and followed the FSM MT-24 page to check the thickness/diameter of all the points listed. Not surprisingly they were all in spec. I don't really see how the output shaft flange would wear, and the journals looked perfect, hardly any wear at all. I didn't check for runout, I had the gear, but I didn't want to set it up for a shaft that was visibly in very good condition. I didn't inspect the synchro rings because I intended to replace them all regardless, as I would recommend to anyone who goes to the effort of tearing down one of these boxes. The edges of the hub forks showed very little wear, and as I intended to replace all the sleeves I didn't bother to measure the existing ones for clearance.

You want to pay close attention to the engagement teeth on the synchro cones attached to each gear. If you've ever grinded gears, it's the surface of these teeth you were grinding. The sleeves are supposed to take the brunt of the wear, and they do, but these teeth will still get worn down over time, and if you attempted a shift with the clutch still fully or partially engaged, these teeth can certainly have taken some damage. Pay particular attention to the reverse gear, which we'll talk about later in detail.

Here's some of my recommendations/guidelines when rebuilding these boxes:

1. Replace all the synchros. Even if they "look good" the sharp edges of the grooves will be flattened, affecting how well they "grab" the cones. New rings may be expensive, but there's really little point going this far if you don't intend to replace them.
2. Replace all the hub sleeves. The hub sleeves and synchros together see the most wear of any parts in this box. The teeth of the sleeves slide against the blocker rings on the synchros when changing gears, and press against them during pre-synchronisation, with the synchros wearing against the synchro hubs on the gears. Finally the sleeves slide against the hard teeth on the gears themselves, hopefully after successful synchronization, but in the case of "grinding the gears" it's the teeth of the sleeves that will fare the worst, being softer than the teeth on the synchronizer hubs attached to the gears.
3. Replace hub 1. The actual hub that locks into the output shaft. The shift from 1st to 2nd sees the most abuse on these boxes. Your second gear is probably the one that's been shifted into the most at speed by an order of magnitude, and it's probably the seen years of abuse after the synchros were shot. This will have taken a toll on the hub itself, which I'll show in pictures later. The rest of your hubs are probably fine, but order a new hub 1.
4. Replace all the hub shifting keys and springs. They're cheap, and the keys will have wear.
5. Replace all needle roller bearings. Look, they're probably fine, but do it anyway. The needle rollers aren't too expensive if you get them from a decent place.
6. Maybe replace the other bearings. This may sound controversial, but honestly, all the bearings I've seen on all these boxes have been perfectly serviceable. Replace the split rear counter gear bearing with the plastic cage, but as for the others? If you needed to save a few dollars, you could do that here. For a 30 year refresh you really should do it. If you only care about the next 5, I wouldn't bother. These larger bearings are very expensive, and I believe the ones in my box could have gone for another 30 no worries. I've put them back in the boxes as emergency spares for the future. If you opt to get a pre-packaged rebuild kit though, these will come with it anyway, so you might as well do it.
7. Preferably get new snap rings, but you can reuse your ones as long as you don't damage/overstress them during removal. I reused mine.

 

[DivByZero]

I'm going to show the reassembly now, and talk about issues of wear, and what I did about it, inline with each step. For parts we haven't fully disassembled yet, I'll show both disassembly and reassembly together when we get to them. First, the output shaft. We're going to go to MT-26 in the FSM - Output shaft assembly.

Step 1 talks about putting the hub sleeves on the hubs. We haven't rebuild ours yet, so right off the bat we're going to deviate and rebuild our hubs. First, we'll need some parts. Here's our new shiny synchro rings we'll be using, three of our four hub sleeves, and the keys and springs, all new and ready to go:

The sleeve for hub no.1, the largest of the four, is something we need to talk a bit about. The original part is NLA, it's been replaced by the part from the later cost-cutting revisions of this box, which used a different synchro design that locked back into the hub with large tabs. This left less teeth on the sleeve for engagement, meaning higher stresses and earlier wear. The original part was 33363-60030, but you can replace it with 33363-60041. Here's the replacement ring vs the original:

You don't really have a choice here if I'm honest. This first hub synchro ring will be chewed up on the 2nd gear side. This is the largest sleeve, so it's still got plenty of teeth left to engage with, it's not as serious as some of the smaller rings if this was to happen for them. You're much better off going with a new sleeve with less teeth than reusing the worn sleeve, so that's what I'll be doing here. A note - this isn't listed as a substitute in the Toyota parts catalog. Don't let that deter you. Substitution info in the catalog is riddled with errors and omissions. H150 boxes were actually fitted with these sleeves (technically 33363-60040) from 1996/08 onwards as part of the cost-cutting measures I outlined in other posts, despite the same hubs and synchros still being used. They are drop-in compatible, and most parts suppliers out there will list this part as a replacement, it's just the Toyota catalog that doesn't.

Now it's time to rebuild those hubs. I've left the fourth hub, which deals with reverse, for later. For now I'm doing hubs 1, 2, and 3, which fit onto the output shaft prior to fitment into the intermediate plate. The critical info is right here in the FSM:

Every one of these hubs and hub sleeves is directional. There will be a bevel on an edge of each sleeve to show orientation. The shifting keys on one of the hubs are also directional. Be aware - they changed design of the sleeves slightly over the years, they may be an angle as shown in the pictures, or a "step" instead. You can compare the "teeth" of the sleeve to doublecheck. Hubs 1 and 2 only have angle-cut teeth on one side, and hub 3 doesn't have teeth on one side at all. Be slow, careful, and methodical here. I took pictures before disassembly of each one so I could triple-check everything with the original setup. You don't want to get this part wrong. Also make sure you offset the shifting keys as shown in 1b. One of the "blown" boxes I picked up for cheap had lost all three shifting keys after a rebuild. From what I could see, the key springs had been "aligned" rather than offset as shown. This results in less force on the "middle" key, which resulted in it coming out, after which the other two managed to do the same eventually and there was a hub with no keys to lock it into the blocker rings, which meant the sleeve ate the blocker teeth from the synchro rings. Don't make the same mistake. Quadruple check your build here, take your time.

Quick word about hub No.1. I recommended replacing it above. Here's why:

All the other hubs were immaculate, this one was not. See the noticeable wear on the teeth? When your synchros go bad, and you're jamming the gear in, the hub sleeve crash locks with the teeth on the synchro hub attached to the gear, and that force carries back through the sleeve and works like a jackhammer on the hub. Every 80 ever built had a worn out 2nd gear synchro a decade ago. You'll want to replace this hub. It'll give you smoother shifting and better engagement.

Now for the actual hub rebuild. This requires three hands as it is, so I didn't really get any in-progress pictures, but first you gently pry the springs off the back and front with a screwdriver, and lift out the keys. Remember one of the hubs has directional keys (not this one shown below), so take note of the original orientation to help sanity-check during reassembly.

All we're keeping here is the hub (actually for this one shown, not even that), but strip it down, and clean it off. Give it a good spray and a wipe, and in particular clean up the inside teeth that engage with the output shaft. Reassemble using new keys, springs, and sleeves. I won't show each hub, they're all the same thing more or less, but in the end they should look something like this:

 

[DivByZero]

Here's a quick snap showing the directional keys for hub No.3, which is a single-sided hub used to engage fifth gear. The single-sided reverse hub also uses these directional keys (it's actually an identical hub).

And here's a picture showing why we replace the shifting keys:

 

[DivByZero]

That's all I have time for now. I'll post more when I can.

 

[mudgudgeon]

Great write up.
Cool to see you go to the trouble of investigating the upgrade to synchros
Good on you for getting as many pics as you did.

A quick tip, for some of the tricky stuff with small clearances where you've used a screwdriver as a pry bar, custom making a tool can sometimes help.
I have a collection of cheap screwdrivers I've bent into custom tools by heating the end red hot with a MAPP gas torch, bend or hammer to shape, let it cool for a minute, then quench in water so the end stays hard. (Quench to soon, they become brittle)
I've made hooks, and mini pry bars that can be really useful.
Seems overkill to do this for a one off job that you managed to do with a screwdriver anyway, but it's surprising how often my mangled scewdrivers get used in awkward spots.
Another option is by cheap small pry bar, and regrind the end for a thinner profile to fit in small gaps. Pry bar will likely not have a hardened end like screw drivers do

 

[DivByZero]

Step 2 - Install fifth gear and hub sleeve No.3 assembly on output shaft
It's now time to start putting the output shaft back together. Before you've done this, I assume you've sourced new needle roller bearings and synchros, and you've inspected the gears themselves for wear and damage. What you want to be looking at with the gears isn't so much the teeth that mesh with the counter gear (although please do inspect those), but the teeth on the synchro hub that engages with the hub sleeve. If these are chipped or badly worn, you need to consider replacing them. I had a few in that camp, and I'll talk about how I handled that below when we get to it.

We also need to clean everything up nicely, which won't be listed in the FSM. I recommend a good blast of the inside of the gear with some parts cleaner and a clean wipe too. It's not just the gears either, make sure you get a brass brush and clean up the engagement teeth that lock into the hubs on the output shaft if you haven't already. They'll be pretty grimy. You should have already done the hubs themselves during the rebuild you did on them.

Now get your parts all laid out. We're starting with fifth gear.

2a - As per the FSM we need to apply gear oil to the needle roller bearing. This will provide lubrication for the bearings and journals on first start before the oil pump pushes gear oil around everywhere. Get on a pair of clean gloves each time, you don't want to contaminate the bearings with dirt or material that'll score the bearings and the journals. This gear uses that split bearing cage so it comes in two halves.

2b/c - Slide the gear, synchro, and roller bearing onto the output shaft. Note what it says about aligning with the shifter keys. This is harder for some gears than others depending on the side you're pressing, and this is one of the hard ones. The synchros have cutouts for the shifter keys to fit into. If you don't have the keys aligned with the synchro ring when you press it, you'll damage your expensive rings. Pay close attention to the alignment in the next step.

2d - It's now over to the press. The FSM doesn't call for this, but I recommend using a good multi-purpose grease on the splines of the output shaft and the hub, where you're going to be pressing the parts together. It looks to me like it was greased in the factory, and I just consider it good practice to assist in smooth driving of the parts without damage.

Remember your hubs are directional! Check the orientation of the bevel on the hub with the pictures you've hopefully taken, and the orientation guide in the FSM.

In order to press this hub, the gear is going to be on the bottom, the hub on the top. This is where you need to be careful about the alignment of those keys. Check it a dozen times as you press the two closer together. You want to make sure the synchro ring doesn't get caught up. FSM calls for a fancy long press tool. You can make do with whatever, some pipe, or a couple of spare arbor plates like I did here.

Step 3 - Install snap ring
Drive in the snap ring with a brass drift. Must be brass! You don't want to risk marring your output shaft or gears.

Step 4 - Measure fifth gear thrust clearance.
I'm honestly not sure how this could go wrong if you've got the correct bearings installed, but as per the FSM we're going to measure thrust clearance as we go. Get a set of feeler gauges and check the clearance. I got 0.18mm-0.20mm here, which is well within the standard range.

Step 4 - Install third gear and hub sleeve No.2 assembly
First, get your parts together.

5a - Lube up the bearing as per FSM. Kind of hold the bearing in a clean glove and slather it in oil a bit. Plenty will transfer to the shaft, I don't bother to lube that separately. Alternatively, you might want to use an assembly lube of some kind if this is going to sit for awhile before reinstallation.

5b/c - Place the gear, synchro, and bearing onto the output shaft in your press. As per last time, I apply a little grease to the splines of the output shaft and the hub before I press them together.

 

[DivByZero]

5d - Once again you've got to be careful about the alignment of the shifting keys and synchro cutouts. Be paranoid. You don't want to mess this up. Take your time. Note that in the image, you'll see I use some bushing press tools. This is preferred where you can, to distribute the load evenly around the hubs as you press them on. I didn't have a suitable tool for fifth, but I'll be using this approach for the rest.

Remember your hubs are directional! Check the orientation of the bevel on the hub with the pictures you've hopefully taken, and the orientation guide in the FSM.

Step 6/7 - Install snap ring, measure third gear thrust clearance.
Wipe away any excess grease and drive that snap ring in. When done, check the thrust clearance again as per FSM.

Step 8 - Install second gear and hub sleeve No.1 assembly
It's now time to flip the output shaft around and start on the other side. First, get your parts laid out.

And here we deviate from Toyota stock again, time for a little upgrade. This one is applicable for all H150/H151 boxes - the second gear needle roller bearing. I did a whole write-up about this in another post. Suffice to say - plastic bad, metal good. Don't use the original 90364-58003 bearing with the plastic cage, upgrade to the 90364-58005 with a metal cage. I show the two in the image above. We'll be installing the metal one, the plastic bearing is just there for reference.

8a - Lubricate the needle roller bearing as per each other gear.

8b/c/d - Place the gear, synchro, and needle roller bearing onto the output shaft. Grease up the hub splines and slide it in place afterwards. Note that we now have gravity working for us, as we're pressing the output shaft other way up. You can line up the synchro keys with the hub when you place it on the press, and everything will stay where it is as you drive on the hub, since the gear is resting against the hub. The bearing shouldn't slip out on you, as it's deeper than the hub.

Remember your hubs are directional! Check the orientation of the bevel on the hub with the pictures you've hopefully taken, and the orientation guide in the FSM.

Step 9/10 - Install snap ring, measure second gear thrust clearance
Once again, drive the snap ring, and measure the thrust clearance.

 

[DivByZero]

Step 11 - Install first gear
This one is a little different. There's no hub to drive, we have thrust washers, pins, and a large roller bearing instead. First, here's the stuff laid out for first gear itself, with our new shiny upgraded triple synchros.

Lube up the bearing and slide it onto the output shaft.

Step 12 - Install ball bearing
12a - We don't head over to the press yet, first we need to install our first thrust washer and pin. I missed snapping a pic of this, but make sure you don't forget this step. You can reuse the pins. I highly recommend replacing the thrust washers. Mine were perfectly serviceable, but did show some wear. Replacing them is the right move.

12b - Now we need to press down our bearing. This is the hefty one that locks the output shaft into the intermediate plate. The original bearing part number for this from Toyota was 90363-45016. This is an NSK bearing, part number 45TM04NC3U40A. This bearing is NLA it seems, replaced by Toyota part 90363-45019, NSK part 45TM04AANC3U401. I have zero idea what the difference between these bearings is. The bearings are identical size, and have identical markings (same as the original bearing). Here is new vs old:

Press the bearing down onto the output shaft.

12c - Install the second thrust washer and pin, this time on this side of the bearing.

I've already installed the thrust washer and pin in this pic, I'm holding the old one in the bag.

12d - Drive the snap ring. Err, not like this obviously, the pic is just illustrative. The output shaft is getting heavy to hold in one hand while taking pics.

And that's it! Output shaft reassembled, or at least as much as it can be before it's installed back onto the intermediate plate.

 

[DivByZero]

That's all the time I have for now. I'll write up some more later.

 

[DivByZero]

For the next stage of the reassembly, we need to talk about the intermediate plate and the front bearing retainer. These are the only steel parts that face the elements on the exterior side of the gearbox. They were painted black at the factory to give them some form of weather protection, but after 30 years they're caked in muck and the paint has had it. For this rebuild, I decided to clean mine up and give them an upgrade to a hardened enamel, to protect them for a long time and make them easy to clean in the future. On the outside at least, the internal faces of the intermediate plate are immaculate, they've been in a perpetual oil bath all their life.

A lot of the tips I'd give here are the same as I gave for cleaning up the brake calipers in my brake system rebuild thread, so you could look there for some more detail. I'm inclined to keep this thread more focused on the mechanical aspects of the gearbox rebuild, but suffice to say, I used a dremel, a bunch of mini copper wire wheels, some cans of degreaser, and a fair bit of elbow grease to clean up the exterior surfaces of these parts. I didn't take pictures of this process, but you can see some info on basically the same thing in that brake rebuild thread.

As for the painting, I used these two paints, Dupli-Color DH1602 black and DH1616 clear.

I highly recommend these paints, they do a fantastic job. Rated up to 1000c temperature, and they bind really well. The catch is - they need to be cured at high temperature. You need to actually bake the parts you've sprayed in the oven at 200c for an hour to heat treat the paint. We're doing a disassembly, so that's no problem, but you couldn't just spray this stuff onto an existing sealed transmission or the like, it won't resist anything until it's cured. Fortunately this makes clean-up for overspray easy. Some isopropyl alcohol will clean up residue easily before cure, so I was a bit lazy with my masking here and dealt with it afterwards.

I didn't take a lot of pics of this process, but suffice to say, after a thorough scouring with the brass wheels and clean with degreaser then isopropyl alcohol, I hit the parts with two coats of black paint, cured them in the oven, then hit them with another two coats of clear and cured again. The black paint gives a nice color and texture, while the clear seals it and gives it that "wet" look rather than a flat matt tone. Overall it should seal these parts well for another 30 years and make them easy to clean.

Here's some progress shots of the cleaning:

Painting

Curing

And the final result

Having the immaculate painted inside of the intermediate plate to compare with, I can safely say it looks better than new.

Oh, and of course I pulled the front oil seal out of the bearing retainer first. No pics of that, but a quick lever with a screwdriver and out it pops.

 

[DivByZero]

It's now time to turn our attention to the input shaft. We haven't disassembled this yet, but it's time to now. Details in the FSM at MT-18, but it's really just two pages talking about inspection and removal/reinstall of the bearing. We'll go through the steps I did here. First, here's the input shaft from this box, with its 12 roller bearings still magically suspended in place:

Note the 21 splines on this input shaft, it's the one designed to mate with the 275mm flywheel found on the 1HZ engine, and the 1HD-T as well in Europe, as opposed to the 14 spline version that goes with the 300mm flywheel on the 1FZ-FE and 1HD-T outside of Europe. This is also the post 1992-08 version for the deeper bearing. Toyota used a shallower, weaker bearing on the H150 boxes before that, and the input shaft has a flange to contact the shallower bearing.

We're going to remove those 12 individual roller bearings and the synchro ring, which come off easily by hand. Next step is to remove the snap ring holding in the input bearing. This one you'll get your snap ring plyers for again.

With the snap ring removed, it's time to press the input shaft bearing off, then we'll inspect everything. Over to the press.

Bearing is off, it's now just the bare input shaft. Time for inspection. Right away, there's a problem evident with this one. Remember how I said to inspect the engagement teeth on the synchro cones? Check these ones out:

Worn, chipped, and shattered. These teeth are buggered. It's like that all the way around. At this point, you could buy a new input shaft. They are still made. Would set you back a pretty penny, but it's certainly an option. I bought a few other boxes for this exact eventuality though. I didn't want to fork over a wad of cash and wait for weeks for parts to arrive. I grabbed another input shaft I had on hand, this from an early H150 box with the shallower bearing.

Teeth on this are looking much better. I don't want the shallower front bearing though, or to change the gear teeth themselves if I can avoid it. What do I do then? Switch the synchro cone of course. Over to the press, let's remove those cones.

 

[DivByZero]

Now we clean up the input shaft and synchro cone good and proper, grease the splines, and press the good cone onto our input shaft.

One nice rebuilt input shaft. Now we're going to press the new bearing.

I didn't take a picture of this apparently, but it's pretty simple. Grease the shaft and the inside of the bearing, place it the correct way around with the shaft pressing down on top, and drive the input shaft into the bearing like I drove the synchro cone on a few images above. After that, reinstall the snap ring, and that's the input shaft basically done. We'll leave the 12 roller bearings until we're going to fit the input shaft to the output shaft again.

 

[DivByZero]

Now it's time to "rebuild" the counter gear.. which really just means change the front bearing that's still attached to it. This is in the FSM at MT-31, but it's really just a few steps. First of all, remove the snap ring holding the bearing in place.

Now it's time to pull the bearing. The FSM calls for using a press and a bearing puller, but you'd have to have a massive gap between the two sides to fit the gear assembly through. Mine doesn't, so I used the three jaw puller instead.

My finger isn't pointing to anything important there, it's stopping the entire counter gear rolling off the bench while I take a picture.

Now this bearing is a funny one, the inner race isn't fully closed on both sides, just the front. When you pull it, grab it by the outer ring so you don't pull out the inner race entirely and drop the roller bearings everywhere. You'll find the side race still on the counter gear shaft. Slide it off.

Clean up and inspect the counter gear, and it's time to press a new bearing. I took the journal diameter measurement as per FSM, perfectly in the middle of tolerance. Worth inspecting, only takes a second. New bearing.

I didn't follow the FSM procedure for pressing this bearing either. I put grease on the bearing races like I've done before, but to minimize the risk of anything going askew, I felt I was best off pressing the shaft down into the bearing first, which I did up until the point shown below where the counter gear shaft end is flush with the bearing race.

I then flipped the shaft over and drove it the rest of the way with a bearing press, then fitted the snap ring.

That's it, counter gear rebuilt and ready to go.

 

[DivByZero]

That's where I'll leave things for today. Next time I'll cover the reassembly of everything back into the intermediate plate and the reinstallation of the shifting system, and anything else I have time for.

 

[DivByZero]

Finally got some time to add more to this story. Where we left off is with the output shaft, counter gear, and input shaft rebuilt and ready to go, and the intermediate plate cleaned up and painted. It's now time to continue reassembly and mount everything in the intermediate plate. Time to go back to the FSM at MT-40 - Component Parts Installation.

Step 1 - Install output shaft assembly to intermediate plate
Before we get started, we've got to mount our empty intermediate plate back in the vice on our workbench, using those bolts through the holes so we don't chew up the mating surface. Get everything together and prepare for installation.

1a - Now we're going to slide the output shaft back into the intermediate plate. I like to put a smear of grease on the outside of the bearing race and the the mating surface of the intermediate plate. The FSM talks about tapping with a hammer to get this thing installed, but honestly in my experience it's a relatively loose fit between this bearing and the plate. It should slide in easily by hand without any force, just get it lined up and in it goes.

1b - Time to install the snap ring for the output shaft bearing. Since it's a loose fit you don't want it dropping out on the bench! It's just the larger ring we're installing from the set shown here in the picture.

Step 2 - Install input shaft
Before we get to step 2a, we need to fit our synchronizer ring to the input shaft. No point installing it before now, we don't want to risk damaging it, best to fit it right before reinstallation. Clean the synchro cone and put the ring on.

2a - Now it's time to place those 12 loose roller bearings inside the input shaft. Grease them up good and proper, and stack them up. They'll lock fairly well into place and the grease will stop them falling off until you complete the stack.

2b - Now that the shaft is all back together, line up those keys on the shifting hub with the cutouts on the ring, and slide the input shaft on.

Step 3 - Install counter gear
This part is a little fiddly. Get some padding installed on your vice so you don't damage the counter gear, as per the removal step. Get your new rear bearing for the counter gear ready to go. It's an unusual split bearing. Note that with a new bearing, the snap ring comes installed with the bearing new in the box. There's no need to remove it, and we don't need the one we originally removed to get the bearing outer race off. When we install this thing, we're just going to slide the entire outer race in with the snap ring installed. The snap ring will set the "depth" of the outer race for us.

3a/b/c - The FSM makes this sound so easy, but really it's quite a fiddly job. No good pictures here I'm afraid, I needed both my hands to do the reinstall, but basically you need to slip the counter gear too far through the intermediate plate, being careful not to damage any of the gear teeth, fit the two halves of the plastic bearing cage together with the race poking out the other side, then move the counter gear back into position and slide the outer bearing race over the edge. I applied grease to the outer edge of the bearing race here, but not to the intermediate plate since it would have gone everywhere when messing with the counter gear.

The bearing race is shown resting here, not installed, but it just slides in with no real force. Certainly doesn't need to be driven in with a brass bar like the FSM suggests, just a smear of grease and it'll just about fall in place. No need to do step 3b as I described since a new bearing comes with the snap ring installed, so unless you're reusing the bearing (which I REALLY don't recommend with this one, given the plastic cage), it's just the outer bearing race to do. Doesn't look like I snapped a pic with the race pushed in but you get the idea. I supported the counter gear lightly with a ratchet to free up my other hand here. A helper would make this step easy, and even if it's just you it shouldn't be too hard, since you won't be trying to snap pictures on the way.

 

[DivByZero]

Step 4 - Install rear bearing retainer.
Since those bearings are fairly loosely installed, we need that bearing retainer to hold the output shaft and counter gear into the intermediate plate securely. The snap rings stop them falling out forwards, now this bearing retainer will stop them falling out backwards. Time to get it fitted. Clean it up and torque the four bolts to 13ft-lbs as per the FSM:

Step 5 - Install reverse gear, hub sleeve No.4 assembly, and needle roller bearing
Now we're up to the reverse gear. As per the other gears, carefully clean and inspect the reverse gear for signs of wear and damage, paying particular attention to the engagement teeth on the synchro cone. When you do, if you've ever found reverse a bit hard to shift into, you'll probably find something like this waiting for you:

Badly worn, mashed teeth. This I believe you'll find typical on these boxes. You see, when the hub sleeves and engagement teeth wear a little, they don't have a nice sharp point anymore, it gets a little rounded. Depending on the exact rotational angle of the gear to the hub sleeve, you can get a "point to point" condition, where these two sets of straight engagement teeth hit each other on the tips. With other gears this is less of a problem, because the output shaft will have a little movement when the vehicle is in motion, and when the gear oil is warm things move more freely. For reverse though, you're often shifting into it from a cold start at a standing stop. If it doesn't slide in right away, what we should probably do is "double clutch" shift, so with the gearstick out of gear (neutral), release the clutch most or all of the way to get the output shaft rotating a bit, getting out of that "point to point" condition and getting a little movement, then it'll shift into reverse easily. What I often do though (and most other drivers I'm sure) is mash that shift a little harder, which is blunting those engagement teeth on the gear and the sleeve, making the problem worse as time goes on.

Well we're here now, what do we do about it? You could order a new gear, but the original part, 33031-60010, is no longer in production. They dropped it years ago for a cost-cutting single-piece cast version:

Yuck. You could go that way if you want, but as it turns out, there are other options available. Unlike the single-piece cast shown above (used from 1996/09 onwards), the original gears are an assembly, with a separate synchro cone pressed onto the gear, as we've shown before. We can swap over this synchro cone. What do you swap from if all the original reverse gears are likely to be a mess though? Chances are, any spare you get will be in similar condition. Well, the synchro cones aren't all unique per gear. Reverse gear actually has an identical synchro cone to 5th gear.

This is fantastic for a number of reasons. While reverse is probably the most likely gear to have mashed teeth, 5th gear is the least likely, since of all the gears it probably sees the least number of shift events over the gearbox life, and with the smallest rotational speed differential of all the gears. In my case, with spares on hand, I had a 5th gear with an immaculate cone I could readily use. Even if this isn't the case for you when doing a rebuild though, the original 5th gear part 33036-60010 is still in production since unlike reverse, it hasn't shifted to a single-piece cast. This means you can buy a new 5th gear, remove its synchro cone, and fit that onto your reverse gear to make it like new again.

I'm going to show that process now, swapping the synchro cone from 5th to reverse, but basically it's the same kind of thing I showed above when I did the three piece synchro upgrades. To pull the synchro cone from 5th, I used a bearing splitter and the press:

To pull the cone from reverse, I used a three jaw puller with one of my bearing press sleeves:

Old vs new:

Now we press the replacement sleeve onto the gear:

We now have a nice remanufactured reverse gear assembly, with neat engagement teeth on the synchro cone.

 

[DivByZero]

With the reverse gear itself sorted, it's now time to proceed with step 5 from the FSM, and install the reverse gear and hub.

5a/b - Get some gear oil on the needle roller bearing, and slide the bearing and gear onto the output shaft, then install the synchro ring. Pretty straightforward.

5 c/d - Now before proceeding, it's time to rebuild the reverse hub. Get your parts together.

You WILL need a new hub sleeve here. It's not optional. You saw the state of the engagement teeth on the reverse gear synchro cone, the teeth on the shifting sleeve are going to be similar, as you can see here:

Rebuild your hub as per all the others you've done to get to this point, and have it ready to install.

5e - It's time to install the hub itself onto the output shaft. We grease the splines as per the other hubs. How are we going to install it though? We can't just use a press, since everything is mounted together in the intermediate plate. The FSM calls for a fancy driver to install this hub. If you have some kind of deep bearing presses you might have something that'll work. I didn't, so instead I got a brass drift and drove the hub on, slowly. I worked my way around, kind of the same way you'd torque a flywheel, a few bangs on one side, a few bangs on the opposite side, shift 45 degrees or so and do another few of bangs, working it slowly onto the output shaft. It takes awhile, but it works. The key is to try and keep the hub as straight on as possible. You don't want to drive it at an angle, as much as possible you want to be driving it when it's aligned straight on. Expect this to take 10 minutes and for your arm to get tired, but eventually it'll go on all the way. You need to be careful of the synchro ring though! As you wail on the hub, it'll be pretty much impossible to keep the synchro ring lined up with the shift keys. This would be the same with the SST tool Toyota use in the FSM. What I recommend is you take some shop cloth, a rag, whatever, something soft, compressible, with some volume to it, and push the ring up into the hub, so that the ring isn't on the gear, it's seated in those keys on the hub as you drive the hub onto the output shaft. Keep on checking its placement frequently. Be paranoid about this, you don't want to ruin the ring, although it is the cheapest of the lot it'll still mess you up and delay things if you have to source a new one. The bit of cloth keeps the ring where it should be as you slowly drive the hub in place, so that's what I recommend, just make sure you move it more and more out of the way as it gets closer. Cloth isn't shown in the pictures below and the ring is against the gear before driving, but don't do it that way. Move that ring up into the hub and put something behind to keep it there.

Step 6 - Install snap ring
As per the FSM, drive that snap ring on with a brass drift.

Step 7 - Measure reverse gear thrust clearance
Same as the others, let's check our thrust clearance on our reverse gear.