H150F rebuild and enhancement - and everything else along the way (dropping the gearbox, doing the clutch, etc) (2 Viewers)

[DivByZero]

Step 8 - Install shift fork shaft No.2 and shift fork No.2
At this point we're ready to reinstall the shift forks and shafts. First one is easy, no locking pins or balls to worry about. Get the shift shaft and fork, install them, and torque the nut to 27ft-lbs.

Step 9 - Install shift fork shaft No.1 and shift fork No.1
9a - Before we install the next shaft, we need to fit the interlock pin inside that long channel in the intermediate plate between the two shafts. I found it easiest to attach it to the end of the magnetic pickup tool, slide it in at the front opening and drive it all the way back, then stick my finger into the shaft opening to "detach" the pin from the end of the pickup tool and keep it in place.

9b - Push the interlock pin into the shift fork shaft as per the FSM

9c/d/e - Being careful not to drop the interlock pin, fit the shift fork, and slide the assembly into place. Torque the bolt.

Step 10 - Install shift fork shaft No.3, reverse shift head and shift fork No.3
10a - First up, install that very long interlock pin into the intermediate plate

10b - Install the interlock pin into the shaft hole

10c/d/e - This shaft needs the reverse shift head installed. I found it easiest here to test-fit everything to make sure I had the orientations all sorted before proceeding, taking care not to drop that interlock pin.

With that all sanity checked, it's time to fit this into the intermediate plate and torque the bolt. We just let the reverse shift head here hang down for now. We don't install the locking ball into the head yet, that comes soon.

 

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Step 11 - Install shift fork shaft No.4 and reverse shift fork.
11a - Once again, first step is getting that locking ball in place in the intermediate plate, before we install the shaft.

11b/c/d - Now we don't have an interlock pin in this last shift fork shaft, but we do have a locking ball to insert inside that reverse shift head we left dangling when we installed the previous shaft. In order to fit that, the best way to go is to install the shift fork and shaft most of the way, but once you get the shaft into the reverse shift head a little bit, leave it there for a second. You should now have the reverse shift head level, and the side-access hole visible to install the locking ball. Place that locking ball in now.

With the locking ball inserted, push the shaft in the rest of the way, and torque the nut on the shift fork.

Step 12 - Install fork shaft snap rings
Now the FSM doesn't mention this, but there are two different sizes of snap ring here:

The smaller snap rings are used on shaft No.4 with the reverse shift head, which has a slightly smaller diameter. The larger snap rings are used on shaft No.3 behind it. Using a brass drift, gently drive them into place, being careful not to send them flying across your workshop.

Step 13 - Install locking balls, springs and screw plugs
We've nearly got the shifting system back together. It's time to do the last part and install the balls, springs, and plugs. First of all, they'll need a cleanup. These screws used loctite from the factory, and they'll have residue that needs to be scrubbed off the threads of the screw plugs before we reinstall them. I prefer to use a small brass brush for these screws which are pretty small and in relatively good nick. You should also cleanup the balls and springs well with some degreaser, removing any old lubricant and residue.

Now at this point you'll need some threadlocker. The original Toyota goo is Threebond 1344, but the FSM lists Loctite 242 as a possible option too. Nowadays, that really means Loctite 243, which didn't exist when Toyota wrote this FSM, but handles oil and grease contamination better while having the same lock strength. I opened a new bottle here since I'd misplaced my open one.

As per the FSM, place in each ball, followed by each spring into the plug holes. After that, take the plugs one at a time, put a smear of loctite on the threads running down the length of the plug, around 1/4 of the way around the diameter, and torque them to 14ft-lbs using a T40 torx socket.

And that's the shifting mechanism reassembled.

 

[DivByZero]

At this point the FSM calls for the reverse idler gear to be reinstalled. That's a terrible idea. No way it magically stays sitting in place when you go to dismount the intermediate plate from the vice, it's going to hit the floor, break teeth, and roll under your workbench. That said, doing a test-fit isn't a bad idea at this point. Now is a great time to stop reassembly, and test what we've done so far. With the shift forks all in place, we can actually test-shift into each gear, and with the intermediate plate mounted, we can turn the input shaft and check the mechanism, making sure everything is engaging as it should, and nothing is jammed or binding up. So to that end, I'm going to go ahead and remount the reverse idler gear now, for test purposes. We'll take it off again shortly.

Step 14 - Install reverse idler gear to intermediate plate
Now the FSM gives no guidance here, just an exploded diagram showing the order of the parts, but honestly that's about all you need. You will need some new parts though. I replaced everything except the shaft and gear, so the bearing, thrust washers, and key.

Replacing the thrust washers is non-negotiable. This is typical wear you can expect to see:

Now it's pretty hard to get this wrong, but there is one interesting case you might run into, which someone actually DM'd me about not long ago. Which way around does the idler gear go? The FSM is silent on that, it doesn't talk about or show orientation, but the idler gear isn't truly symmetrical. While the gear teeth can mesh either way around, there is a bevel on one side. You can see it above, there's a "lip" on the surface of the inner cylinder of gear, surrounding where the shaft slides in. That bevel is only on one side, not the other. From the boxes I've torn down, that bevel has always faced the front of the case, so on the inside next to the intermediate plate. Here's a better pic of that lip from earlier during disassembly, showing the original orientation:

It's worth noting that this bevel seems to be purely a tooling artifact. The idler gear will happily install in either orientation, and indeed the gear has identical measurements from the gear face to the outer edge in either orientation. It is in fact reversible, which is probably why the FSM doesn't mention orientation. That said, you should install the idler gear back the way it was originally oriented, so that it meshes with the gears in the same way it always has. It's already been "worn in", so you want to keep that orientation. Technically, it could be possible that boxes shipped from Toyota either way around. In the ones I've seen however, the bevel has been facing towards the front of the box as shown.

Anyway, put the idler gear back together and fit it to the intermediate plate.

At this point, you can mess around with the gear assembly a bit, but a few precautions first. There are a few things you should note:

• The input shaft isn't secured to the output shaft in any way, it's just kind of floating there. It won't just fall off on you, but if you're turning the gear assembly, you might want to hold by the input shaft and push back gently towards the intermediate plate, to make sure the gear teeth on the input shaft stay properly meshed with the counter gear.
• You can drive the shift forks by pressing/tapping on the shift fork shafts, but there's nothing stopping you "overdriving" them right now, meaning you could slip the hub sleeves entirely off the hubs. Try and avoid doing that. While you could fix them up without pulling everything apart, it'd be a bit of a pain.
• Nothing stops you engaging more than one gear at a time right now. Don't do that obviously, it can't work and will stress the gears.
• Make sure the reverse gear idler assembly doesn't work its way out.

So here's me messing around with the gears at this point. I tapped lightly with a brass drift on the ends of the shift fork shafts to switch gears. You just need enough force to overcome the resistance from the springs. You can turn the input or output shaft to inspect the gear assembly, make sure everything is happy.

Once you're satisfied everything is as it should be, take a second to admire your work.

Now remove that reverse gear idler assembly and stash it for later. You don't want to leave it in place and forget its there when you unmount this thing from the vice.

 

[DivByZero]

I'll leave things there for now. More updates soon.

 

[DivByZero]

Continuing on from before, we've done our bench-test of the transmission and everything is looking good. We're not going to continue with reassembly right away though, we're going to turn our attention to the transmission case. Our case looked pretty dodgy. Lots of grime and build-up on the outside. If you're going to go to all this effort, you may as well make the case look a bit nice. This is something you should do in parallel with the rebuild steps, no need to wait until now to do it, and in my case I had this ticking away in the background while I was doing the gears. I ended up getting my case sandblasted. This is something you can do yourself at home, but I really couldn't be stuffed. I have a good engine rebuilder nearby and figured I'd see what they'd charge to do the work for me. For $80 I got the entire transmission case and bellhousing sandblasted. Worth it. Here was the case before and after:

Chem-tanked, sand-blasted, and a vanishingly thin spray of paint in these pictures. I was hoping to go bare aluminium with a clear coat alone, but far too much material would have had to be removed with all the grime embedded into the microscopic pits in the surface. I decided to paint and clear coat instead, which honestly looked much more like raw aluminium than I expected it would. I won't run through all the steps, this is more about the gearbox rebuild itself, but suffice to say, tanked, sand-blasted, masked, high temp enamel painted, oven baked (same kind of paint as we used for the intermediate plate). For the case, we only do the outside, the inside doesn't need or want this coating. It came out looking a little like this:

We also did the bellhousing as I said, but for this we do both the inside and outside surfaces, since it's all "external" and exposed to the elements. It came out like this:

I used Dupli-Color DH1606 aluminium and DH1616 clear for these parts, baked in the oven like the intermediate plate. The bellhousing was a squeeze but it fit in there too.

With the case having had the necessary attention, we can proceed with the reassembly.

 

[DivByZero]

I lied, there's something else to talk about before we proceed with reassembly. There are some other parts I haven't shown the rebuild process for yet, which it's best to have sorted out before you reassemble everything. First one we'll cover is the oil pump. Instructions for this are in the transmission manual in their own section, called "Oil pump cover". Get them in hand and we'll go through them. To start with, you should have the oil pump assembly we bagged during disassembly:

It's worth noting there's two versions of this housing, something not mentioned in the service manuals, even later editions. There's an earlier version of the pump cover with a grub screw on the side of the housing, and a later version introduced in March 94 that omits it. You can see both versions here:

The grub screw serves no purpose, it seems to be due to tooling limitations in the earlier design. They needed to provide a diagonal oil channel in the cover, and the original design has two straight holes drilled that intersect, with one drilled from the outside of the housing. The grub screw closes this outside drill hole off to keep the oil inside where it's meant to be. In the later revision they were able to drill a diagonal passage and there was no external hole to be closed off. I'll be rebuilding the later version here without a grub screw, but yours might have one as shown above.

Anyway, moving on. First step is checking clearances as shown in steps 1 and 2 in the FSM. I did this, but won't bother providing pictures or going into it. It's all in the FSM, a simple check, but likely unnecessary since the pump showed no meaningful signs of wear on my box after 30 years.

Steps 3/4/5 - Remove oil pump drive rotor, driven rotor, o-ring
This is pretty straightforward, but be aware that the pump rotors can feel "stuck" to the cover by a layer of oil coating them. There's quite a bit of surface area contact to the case itself. You'll probably find they rotate easy but don't exactly fall off into your hands, but you don't want to scratch them up trying to pry them off or mar the housing by bashing on it. Best thing is to give the entire area a good spray of degreaser to release the seal. After that they should come out easily. Gently pry out the oring.

Step 6 - Remove screw plug, spring, ball and valve seat.
6a/b/c - As per the FSM, use a H10 hex bit to remove the screw plug. I rattled this off. Be careful not to lose the ball and spring below. Bag and tag them.

6d/e - The FSM tells you to pull out the valve seat using a magnet. It won't work. The valve seat has an oring on the end that'll hold it in tight. I got it out by giving the cover a sharp tap on my wooden bench over the hole. Came right out. Once you've got it free, pry off the small oring with a small flathead screwdriver. We have a replacement in the gasket kit.

Step 7 - Remove taper plug
I skipped this step because I have the later revision pump that doesn't have this plug.

Step 8 - Remove oil seal
As per the FSM, pry out the oil seal.

At this point you should give everything a good clean and inspect for issues. You'll need to have your gasket kit for reassembly, part number 04331-60200. We'll be using this kit for a number of seals in the box. I also had a new screw plug in my set of parts, so I used it. Totally not required.

 

[DivByZero]

Assembly of oil pump cover assembly
Step 1 - Install oil seal
The FSM calls for you to drive the oil seal into the pump cover using a hammer and a seal driver. I don't use that approach, I think it's far too aggressive and increases the chances of damaging the seal and/or the housing. My preferred method is to apply a thin film of grease to the outside edge of the oil seal, then press it in gently with my thumbs. It doesn't take as much force as you might think, and you have full control over depth, and will feel it if its going in wrong or getting bound up.

Note that there's a bevel on the inside edge where the oil seal is seated. The oil seal isn't flush with the face of the housing, it sits at the base of that bevel. Basically you want the outside edge of the seal to stop where the bevel starts. This matches what I observed on the oil pump cover on my box originally and the others I looked at.

Step 2 - Install valve seat, ball, spring and screw plug
2a - We now need to replace the oring on the valve seat. Get into that gasket kit (04331-60200) and you'll find not one, but two orings, with very similar but slightly different dimensions.

It's moments like this where it helps if you bag and tag all your used parts as you go, even things like orings you don't plan on reusing. The FSM gives no help to determine which oring is the right one here. By comparing with the used one I could tell it was the larger of the two orings needed here, but I'm sure the smaller one would have gone over that lip with encouragement, the old oring was a tight fit too, doubt you'd notice the difference. Make sure you get this right, you'll be needing the smaller one later.

2b/c/d/e/f - As per FSM, we need to apply gear oil to the value seat here. Make sure it's properly lubricated, then push it gently into the cover. Now lubricate the ball and drop that in, followed by the spring.

2g - Now we need to install the screw plug and torque it, but be careful! The FSM doesn't mention here that this screw plug originally had loctite on it. You'll find the green residue in the threads (which you should have cleaned up). I bought a new screw to confirm this is how it comes from the factory, and sure enough, the new part comes with loctite pre-applied:

If you're not using a new screw like I did here, apply some Loctite 243 like we did before, and torque to a measly 13 ft-lbs.

Step 3 - I skipped this since my version doesn't have a taper plug.

Step 4/5/6 - Install oil pump driven/drive rotors and oring
As per FSM, lube up the drive rotors, and install them, followed by the oring. We now have a rebuild oil pump assembly.

It's now time to get another part ready for reassembly - the front bearing retainer. Very simple - pry the old one off with a screwdriver, and install the new one. I removed the oil seal earlier when I painted the housing. The new seal comes in the gasket kit we used before. This time the FSM calls to use a bearing driver tool and a full on shop press. That's like using a nuke to swat a fly. Ignore the FSM, just get the seal, put a little grease on the outside edge like we did before, and press it in with your thumbs. There's an illustration in the FSM this time showing that there's a bevel on the inside edge here too, like we saw on the oil pump. We need to press it in so that it sits just at the base of that bevel. Note that the FSM shows it is possible to "overdrive" this oil seal. Just press it in slowly and carefully with your thumbs and that won't be a problem. You certainly don't need an obscure SST and a 20-ton press.

And that's the front bearing retainer taken care of.

I should mention - when doing these oil seals, I always grease the inside lip too where it rides on the shaft. The FSM doesn't mention it, but I consider it standard practice with rubber seals like this. They shouldn't go on dry.

 

[DivByZero]

And I'll have to leave it there again. Hopefully I'll finish this write-up soon, we're getting close to the end now!

 

[DivByZero]

We're now going to continue with the reassembly instructions, but we're going to do them out of order. The order shown in the FSM isn't viable. You see, you're going to be bringing the two halves of the case together at the intermediate plate, and torquing the bolts. Between all these parts there's liquid FIPG applied. Once you start running a bead of this stuff, you've started a clock running. The gasket starts curing on contact with air, and you need to get the parts together and fixed in place at their correct tension, or the gasket seal could be compromised. This means getting all your prep work done beforehand, so you can get all the parts together quickly. I'll list the order of instructions in the sequence I recommend doing it for this following bit.

Step 18 - Install oil receiver to front case
I didn't take pictures of this, but before sandblasting and painting I removed some parts. On the front case there's a long oil receiver that runs down the length of the inside and protrudes slightly from the rear. Very simple, two bolts hold it in place. Assuming you've removed it before, it's time to reinstall it. Fit it into the front case and torque to a tiny 9ft-lbs.

Step 23 - Install oil strainer to transfer adaptor
On the rear case section there's an oil strainer I haven't shown or mentioned before now, but I removed it when I cleaned up the case. Very simple, two bolts, and a small oring on the end. You could reuse this part if you're up for doing a lot of cleanup, but you should expect it to be pretty gunked up. If you wanted to clean it properly, you'd really have to bend back the metal edge holding in the mesh, so you could remove the mesh and clean inside. Since this part is still available new and fairly cheap though, I opted to replace mine, which is what I'd suggest you do too. Note that the new part does NOT come with an oring fitted, this is where you use that other smaller rubber oring from the gasket kit and fit it to the end. Push into place and torque the two bolts to 9ft-lbs.

Missing step - Prep your bolts
Assuming you're reusing your case bolts (and there's no reason not to), you'll need to get them all cleaned up. They'll have red FIPG material on the threads, as well as dirt and grime on the head. It's time to give them a proper clean, which I do using a brass brush on a dremel. Your gasket surfaces on the intermediate plate, and both halves of the case will also need to be fully cleaned of residual FIPG material. I did mine when I cleaned and painted the case, but if you skipped that, now is the time to get those surfaces ready for reassembly.

Missing step - Lay everything out and get ready.
We're about to do some time-critical steps. Make sure you know exactly what you're about to do and where everything is. This process is complicated by the fact that we don't just need to get the two halves of the case together and all the bolts torqued, we also need to reinstall the shift lever shaft and housing halfway through, with the clock still running on our gasket. You shouldn't rush, but ideally after we apply the first bead of FIPG, all the steps up to and including torquing the case bolts are completed within 10 minutes. Here's what we'll be working with:

The ThreeBond 1207C is OEM Toyota Red. That's Mr-T uses. I buy it in the brand because it's half the price of the one with a Toyota logo slapped on it, and available in any good local parts store here down under. I had an open tube so I used that. I had enough remaining in that tube to complete this job, with a small amount remaining. The isopropyl alcohol is what I use to wipe down the gasket surfaces prior to applying the FIPG. They need to be totally clean and free of oil residue, or the gasket won't stick properly. The grease is for the front bearing outer races when we fit the case, so that they slide in easily. We'll be using Loctite 243 on the bolts for the oil pump. The torque wrench will be used for all the bolts to torque to the correct spec. Note that I also have the shift lever shaft and housing in the pics, along with the locking pin. If you haven't already, give them a quick clean now, because we're going to install them halfway through this process.

Step 15 - Dismount intermediate plate from vise
Like when we mounted this in the vise, a second pair of hands here helps. I didn't have a helper and used my improvised gantry and a ratchet to support the gear assembly around the counter gear, put some padding down on the back of the vise, and loosened the jaws. I lifted the entire assembly off, and set it on my other workbench, laying on the output shaft.

Step 16 - Install oil receiver to intermediate plate
Now we reinstall the oil receiver we removed just before we mounted the intermediate plate. Three bolts, all accessible with the gear assembly sitting on an angle like shown. Make sure you've given it a clean.

 

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Missing Step - Prep the reverse idler gear
We did a test fit of the reverse idler gear earlier. We're not going to install it right away, but we do need it ready to install quickly. You should get the reverse idler gear together with its bearing, thrust washers, and woodruff key. Make sure everything is together properly and set it aside. Like the picture shown earlier, it should look something like this:

Step 19 - Assemble transmission case and intermediate plate
Here we are, time to fit the case back on the gear assembly. The front case comes first, the big part. Do your final checks now to make sure everything looks good. This is also your last chance to stop and plan the steps that are going to follow. Once you start reassembling the case, you can't stop until the main bolts of the transmission are back in place holding the two halves of the case together. Once you're ready, take a clean wipe of some kind - a clean cotton rag or shop wipe that won't leave material behind, load it up with isopropyl alcohol, and immediately wipe down the mating surface of the transmission case. Do the same to the mating surface of the intermediate plate. Don't touch those surfaces from here on out. Now we open the FIPG material and lay a bead down around the mating face on the transmission case. There's an image in the FSM showing where to run the bead, which shows a bead down one side of the bolt holes. I don't follow that. In my experience, when any seals like this fail, they always fail around bolt holes. I like to come back and join a bead around the other side of each hole.

If you've never used this FIPG material before, be aware that it can be harder to squeeze out of that tube than you might expect, and it can quickly make a mess if you shift around too much or try and push it with the nozzle. Ideally you can run a nice, clean, even bead all the way around, with a consistent thickness. Unfortunately the day I did this wasn't my best day, and mine came off looking a bit messy:

Certainly not my best work, but it'll still seal just fine. It's the thickness you've got to be most aware of. When we put the case together and torque things down, this is all going to compress and come spilling out both sides of the case. I aim for what I suppose is around a 2mm bead on a flush surface like this. I basically eyeball it. A few parts in the image above seemed a bit thin to me, and I went back and filled them out a little in a second pass before fitting. No pictures, I was on a clock to install, but basically you don't want too much material so that it intrudes into the inside of the case or the bolt holes excessively. Less is more. You want enough so that when the case is squeezed together, the gasket material fills the gap entirely, while minimizing the amount squeezed out. A bit of practice/experience involved, but use the picture above and the illustration in the FSM as a guide.

With the FIPG now curing, we need to get the case fitted. Bring it over to the workbench, where your gear assembly should still be raised on an angle ready to meet it, with a clean mating surface. At this point, a step is needed that's not in the FSM. Get out your grease and apply a little to the outside of the front bearing races. Doesn't need much, just enough to help them slide into the case easily. With that done, carefully, very carefully, lift the case with the FIPG material on it, and carefully slide it over the gear assembly. You must not get any FIPG material on the gears. You also really need to avoid smearing it around the mating surface. Lower it down carefully, to try and get it lined up just right. The bearing races will contact the case as you go and start giving resistance, which will stop you bringing the two surfaces all the way together. At this point, as the FSM shows, be prepared to give a few gentle blows with something like a rubber mallet or deadblow hammer. Keep the case aligned as you go, you do not want to have to twist, shift, or separate these surfaces once they contact, it'll mess up the FIPG and you'll risk having areas that are too heavy or too light on material.

The bolts aren't in yet and the gasket is still curing. We need to move on immediately to the next steps.

Missing step - Reposition the gearbox
At this stage, I lay the gearbox down flat, right side up. We need access to the shifting system at the top for the next step.

Step 22 - Install shift lever shaft and shift lever housing.
We need to do this now, as it has to be done after the front case is installed, but before the rear case is installed. Note that the shift lever shaft has an orientation! There is an oil hole in one end and two holes for the oil to escape down the shaft. This delivers oil to the shifting system. You need the shaft oriented so that the exit holes sit behind the shift lever housing, as shown in the image below. I also drove the slotted pin back in place. Push it in a little and a few taps with the brass hammer takes care of it easily, just don't drop it into you transfer case! If you do, you'll be taking it back apart and cleaning all that FIPG material off before you can try again.

Missing step - Reposition the gearbox
Before we can do anything more, we need access to the back of the gearbox. What I did to make this possible was rotate the entire case so that the input shaft was hanging off the edge of the workbench, with another bench/block beside it to support the case. In other words, the front of the case was pointing directly down, and the back of the case was pointing directly up. You'll need to do something similar so you can properly clean that side of the intermediate plate and install the idler gear without it falling out.

Step 17 - Install magnet to intermediate plate
If you tried to do this earlier it'd probably have fallen off by now. It's time to replace the magnet. I say "replace" because I just bought a new one. Cleaning fine metallic paste off a powerful magnet wasn't my idea of a good time. You can clean up yours if you want, no reason it can't be reused, but it was still available and cheap so I got a new one. Install to the intermediate plate in a little nook below the idler gear.

Step 14 - Install reverse idler gear to intermediate plate
We now install the idler gear for real. If you had it all laid out and ready to go, this'll be simple enough, just don't lose that woodruff key or drop the thrust washers. Make sure you've got the thrust washers with the dimpled sides facing towards the gear, that way they can hold oil and lubricate the surface like they're supposed to.

Don't forget the reverse idler gear! You are on the clock here, so it may be an easy thing to do.

Step 24 - Install transfer adaptor (rear case)
Time to clean up the mating surfaces of the rear case and the intermediate plate, and break out the FIPG again. Same as before, run a bead around the case:

 

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Now fit to the intermediate plate, and immediately start installing those bolts. Try and get in loosely all around first, then drive a couple of opposing bolts in to the torque spec of 27 ft-lbs. That'll help compress the FIPG somewhat evenly. Do NOT overtighten these bolts, you'll squeeze all the FIPG out and be left with a weaker seal as a result. Because I like to live dangerously, I did use power tools to zip the bolts in most of the way before proceeding to tighten with hand tools. That does same some time, there's a lot of thread on these bolts and 11 bolts to do. Just be aware of the implications if you go too far and overtorque while using the power tools. Best case you've created a weaker seal with the FIPG. Worst case you've got to pull it all apart and do it again.

Whew! If you've reached this point, you can put the stopwatch down and take a break. We're not done with FIPG yet, but we don't have anything actively curing anymore waiting to be torqued down.

 

[DivByZero]

Missing step - Reposition the gearbox
At this stage, I lay the gearbox down flat again, right side up. We need access to the bearings at the front of the case.

Step 20 - Install bearing snap rings
As per the FSM, lets reinstall the snap rings for the front bearings. I personally found it easier to do this by hand rather than use tools. They're very large rings. Just get one side hooked in, and work it around the outside, and it'll just pop itself right into place. Note that you may have to pull the shafts towards you to get the channels for the snap rings fully exposed. This is easy for the input shaft, just pull it gently forward. If you have problems with the counter gear, you may have to pry gently in the channel to pull it forward.

Step 21 - Install front bearing retainer
Similar to the case install, for this we get our isopropyl alcohol and clean both the mating surfaces of the case and the bearing retainer. We then run a bead of FIPG material, and being careful to line things up, push it gently onto the case. Put one screw in finger tight to hold it in place, but don't torque yet, because as per the FSM we need to apply threadlocker to these bolts.

With the retainer plate in place and held by that temporary bolt, get your hardware, apply threadlocker, and install them one by one. You'll see FIPG material on that bolt picture above, because I started putting these in without the threadlocker at first - I'd forgotten it, so I had to pull the bolts out, quickly clean them up with a rag, and reinstall with the threadlocker. It's easier if you get it right the first time. Torque to 12 ft-lbs, and try and do it in an even pattern in a couple of stages like we did before.

Step 25 - Install oil pump body
It's now time to install the oil pump on the back of the case. We rebuilt this earlier, so it should be ready to go. First of all though, make sure you haven't lost the two pins that fit into the output shaft. They'll hopefully be stored away securely in the bag you put the pump in. Get the pump, the pins, and the cleaned up bolts together:

Now orient the output shaft so that the two holes for the pins are horizontal, to stop them falling out. As per the FSM, apply a little grease to them and install into the output shaft. These pins are so small I chose to use the magnetic pickup tool to install them to lessen the chances of dropping them.

With the pins installed, align the cutouts on the driven rotor in the oil pump with the pins, and slide the assembly on until it locks onto the dowels. Note that there's no gasket material here, the oring does the job of sealing the channel, and you must not apply any. If you do, you risk likely clogging some of the oil channels in the pump. We do however have to install loctite to the bolts here that secure the pump. Loctite each bolt and torque to 12 ft-lbs.

 

[DivByZero]

That's where I'll leave things for now. Next time we'll do the shift lever control retainer.

 

[DivByZero]

Bumping this thread to say I haven't forgotten about finishing this write-up. I ended up moving house, and between work and life I've barely had a spare minute lately. The gearbox rebuild wrapped up months ago for the record, it's been back in the vehicle for ages and it's been fantastic, I haven't neglected this because it's all gone pear-shaped or anything, just need to find the time to close this off. Hopefully before I forget everything about the last few steps...

 

[frankenyota]

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:
View attachment 3650605View attachment 3650606View attachment 3650607

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:
View attachment 3650608

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:
View attachment 3650609
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:
View attachment 3650610View attachment 3650611
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.
View attachment 3650612View attachment 3650613

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:
View attachment 3650614

Some great tech tips in this thread @DivByZero . I am currently chasing parts for my H151 gearbox build and ordering a new sleeve which can only be the later version as mentioned above (from a H150, VDJ79 gearbox)
The No1 hub is NLA from Amayama and wondering if the later No1 hub from the same VDJ gearbox would also upgrade?
Old number is 33361-60010 and newer number is 33361-60031.(VDJ79 H150 box)
Also the filter pick up screen is NLA.
Might be able to source the original No1 hub from elsewhere but at double the price.

Thanks Matt