Checking fluids on H42 swapped into '91 FJ80? (1 Viewer)

[mvdm]

Hi, I'm new, and very tempted to buy a '91 FJ80 (3FE) that's for sale locally. I took it to the Toyota dealer and got one of the more experienced mechanics to take a look at it. There's some good and some bad. But one thing no one could figure out is this: some previous owner swapped in a H42 manual transmission and transfer case. The 2nd gear synchros are in bad shape, so I want to check the trans fluid to get a better idea of what shape it's in. But how?? There is a weird hose with banjo bolts connecting the H42 to the transfer case, see pic. Any ideas what is going on there, what's that hose for? How to check the fluids?

Anyway, I want to use the truck for light adventure (day hikes, mountain biking, xc skiing) and for trips to the local home depot as I do some work on my house. I'm comfortable doing basic maintenance tasks and simple repairs, but don't have the expertise or tools for more complex jobs like head gasket replacements and transmission rebuilds. Any words of warning, or encouragement, are welcome -- am I taking on more than I can handle with a modified truck like this?

 

[jonheld]

The seal between the transmission and transfer case went bad and one was pumping oil into the other. This hose was supposed to be a "temporary" fix to keep oil in both units.
How's that for a guess?

 

[gummycarbs]

What @jonheld said. Seems somewhat common over in the 40/55 forum.

Transmission pumping oil into transfer case?

I read that when the seal goes between the tranny and transfer case the oil would overfill the tranny. What could be the cause of the transmission pumping oil into the transfer case and leaving the tranny low? How hard is it on the tranny to drive a long distance with it like this? I have no...

forum.ih8mud.com

Gearbox leaking into Transfer Case

Hello all My Gearbox (5spd H55 manual on a 2h) appears to be leaking oil into the Transfer box. I just took 2 litres of oil out of the transfer and put it back into gearbox. The transfer also appears to be leaking oil around its gaskets (not surprising with so much pressure). I think it is...

forum.ih8mud.com

It's a band-aid fix that may not even work:

Transmission to Transfer Case By Pass Hose Concern

Recently I saw several threads about using a hose connecting the transmission fill plug to the transfer case fill plug. The theory is this hose will save you transmission and transfer case if a seal connecting the two goes bad, and one or the other forces oil into the other case, leaving that...

forum.ih8mud.com

 

[Stuckinthe80s]

In the big scheme of things, it really isn't any different than a manual swapped 62 series. The bell housing they used to do this swap is stamped "3F" and the H42 was designed to bolt directly to it. Actually, what I should probably say is that the H55 was designed to bolt to the 3fe (sorta). You'll need to make sure that the H42 is a later style with an adapter between the tranny and the transfer case. This makes it dimensionally identical to the H55 and if you get to that point, an H55 is a direct replacement for you to get 5th gear.

I had an H42 swapped into my 1992 80 series for about a year and a half and I really liked it. Well, I liked it better around town, not so much on really technical trails where I had to be a tap dancer to control momentum and on the highway where the lack of overdrive gets old. The only reason I don't still have it is because my wife totaled her 100 series and now I'm putting the 2uz into my 80.

If the H42 needs a rebuild, they are pretty simple and it should be a relatively easy job for a decent tranny guy. They are also relatively easy to find for a few hundred $$$ as people toss them in favor for an H55. I would probably pony up the extra cash for the H55 vs having a H42 rebuilt though. Toyota still sells the H55 new for around $3k.

One thing I would check for sure is how the clutch pedal is mounted. There is a factory pedal bucket available but people also fab something up sometimes to bolt to the firewall. This is what I did and the firewall started to tear from the constant use. This isn't the end of the world, just something to look out for.

Again, all this to say I wouldn't fret about this kind of swap other than a matter of preference between manual and auto. Toyota designed these pieces so that they bolt right up and you just have to know what years this setup came in from the factory when you go ordering spare parts.

 

[mvdm]

Thanks all, that explanation makes perfect sense -- puzzle solved!

So the correct fix would be to remove the temporary hose, somehow flush the fluid (and metal shavings, I suspect) out of the tranny and transfer box, separate them, install a new seal, and bolt back together?

Or drop in a H42/H55 that's in better shape "while you're in there"...

One thing I would check for sure is how the clutch pedal is mounted. There is a factory pedal bucket available but people also fab something up sometimes to bolt to the firewall. This is what I did and the firewall started to tear from the constant use. This isn't the end of the world, just something to look out for.

Nice, I hadn't considered this. If the car has the wide brake pedal that's used in automatics, does that mean it doesn't have the factory pedal bucket for a manual (which I assume would have a narrow brake pedal)?

 

[mjosoba]

Thanks all, that explanation makes perfect sense -- puzzle solved!

So the correct fix would be to remove the temporary hose, somehow flush the fluid (and metal shavings, I suspect) out of the tranny and transfer box, separate them, install a new seal, and bolt back together?

Or drop in a H42/H55 that's in better shape "while you're in there"...


Nice, I hadn't considered this. If the car has the wide brake pedal that's used in automatics, does that mean it doesn't have the factory pedal bucket for a manual (which I assume would have a narrow brake pedal)?

The factory bucket mounts should be there. But I think meant that some people fab up mounts instead of utilizing the factory setup, using the mounts that are there.

Edit: So all US spec 80’s were auto. So it could still have the wide brake pedal, but also utilize the stock mounts, if they bent the clutch to the side. Maybe shoot some pics of the clutch bucket mounts.

 

[gummycarbs]

So the correct fix would be to remove the temporary hose, somehow flush the fluid (and metal shavings, I suspect) out of the tranny and transfer box, separate them, install a new seal, and bolt back together?

The transfer case has to come out to get to the transmission. The question then is whether you can replace the seals without tearing it down further. Personally, I would probably want to disassemble it at least partially to inspect it. See if the bearings, races, and teeth all look good.

You already know that the transmission has to be rebuilt, so no point in flushing it beforehand.

 

[Stuckinthe80s]

yeah, like @mjosoba said, the brake pedal bucket would be the same for auto and manual but the auto would have a wider pedal pad. If the person doing the swap used a factory pedal bucket, it pretty much bolts right up next to the brake pedal bucket. The way you can tell is, well, looking at it and look down into the cowl near the windshield on the outside of the vehicle. The factory clutch pedal bucket support bracket bolts to the well of the fresh air intake cowl (whatever it is called) This 80 wouldn't have nut spot welded there from the factory but it will have the indent that would be used to locate it and you would see a bolt running up through a nut in that spot.

Here is a thread for reference:

80 series clutch pedal install Help.y

I have started to install a spring over center toyota clutch pedal in my 1992 80 series. I have drilled the two holes on the firewall and have it lined up however it seam strange having the assmbly sitting on the firewall on those small tubes and not the flat metal. I also do not have any place...

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[Toyoland66]

Pulling and reinstalling the transmission and t-case as a combo isn’t very tough. You have to disassemble the t-case down a ways to replace the input seal. No way I would attempt it in the vehicle.

I would bargain a good price with the known issue and swap in a H55. Do you have a side pic to determine if you have a long or short h42?

Also notice that the wire harness next to the speedo cable appears very close to the driveshaft flange.

 

[alphaeighteen]

In the big scheme of things, it really isn't any different than a manual swapped 62 series. The bell housing they used to do this swap is stamped "3F" and the H42 was designed to bolt directly to it. Actually, what I should probably say is that the H55 was designed to bolt to the 3fe (sorta). You'll need to make sure that the H42 is a later style with an adapter between the tranny and the transfer case. This makes it dimensionally identical to the H55 and if you get to that point, an H55 is a direct replacement for you to get 5th gear.

I had an H42 swapped into my 1992 80 series for about a year and a half and I really liked it. Well, I liked it better around town, not so much on really technical trails where I had to be a tap dancer to control momentum and on the highway where the lack of overdrive gets old. The only reason I don't still have it is because my wife totaled her 100 series and now I'm putting the 2uz into my 80.

If the H42 needs a rebuild, they are pretty simple and it should be a relatively easy job for a decent tranny guy. They are also relatively easy to find for a few hundred $$$ as people toss them in favor for an H55. I would probably pony up the extra cash for the H55 vs having a H42 rebuilt though. Toyota still sells the H55 new for around $3k.

One thing I would check for sure is how the clutch pedal is mounted. There is a factory pedal bucket available but people also fab something up sometimes to bolt to the firewall. This is what I did and the firewall started to tear from the constant use. This isn't the end of the world, just something to look out for.

Again, all this to say I wouldn't fret about this kind of swap other than a matter of preference between manual and auto. Toyota designed these pieces so that they bolt right up and you just have to know what years this setup came in from the factory when you go ordering spare parts.

What are you doing with the old H42 if you don't mind me asking

 

[Stuckinthe80s]

What are you doing with the old H42 if you don't mind me asking

I sold it a while back.