Transfer Case Swap - A Couple Questions (1 Viewer)

[bicycleagent003]

Hey Mudders,
I bought a used T Case to swap into my rig while I regear my original T case. Tomorrow I am going to swap in the used T case so that I can keep driving my 80 while I regear its original T case.

Couple questions:
- Am I going to lose/spill any ATF out the backside of the torque converter? I'm hoping no.
- How do I ensure that the CDL is in the proper position on the temporary T case I am swapping in? I watched OTRAMM's videos (real gold there) and I saw him fiddling with the T case at the top after removing the locking motor, but he doesn't describe or show what he's doing there. What am I looking for? Can I just put the donor T case in without removing the center diff lock motor?

Please feel free to throw any tips my way. I've never done this before and I'm a bit intimidated by the project. Any advice would be happily accepted.

Thanks.

 

[Fosters]

If just dropping the T case…you should lose any atf from the transmission

You won’t need to lock the cdl,
If your donor T case has its own cdl actuator it’s a simple plug and play deal…if not you’ll be pulling the cdl actuator from you old t case and swapping it over to the new case…this is when you’ll need to manually check that the t case isn’t locked

 

[CharlieS]

If I recall correctly, the fsm says to lock the center diff switch before removal. I'd recommend reading the fsm to be sure. I forgot to do this the first time and it was no big deal, I just made sure the switch position was the same as the physical position when I reinstalled (locked the switch and made sure the actuator gears were in the locked position). Agree that you shouldn't expect to lose transmission fluid, but DON'T start the car when the transfer is removed, it will hemorrhage ATF. There are electrical connections on top that Ryan might have been fiddling with, or reconnecting the linkage. Keep an eye on the H-N-L actuating rod as you reinstall, it can get jammed up if you aren't careful. As said above, if both t-cases have working CDL actuator motors, you shouldn't have to do anything, just swap in the spare transfer case with the CDL actuator intact. Plug in a few connectors, reattach the breather hose, reconnect the linkage, reattach the driveshaft, and you're done.

 

[bicycleagent003]

Great. Thanks, guys. I appreciate your advice, thanks for taking the time to share your wisdom.

 

[CharlieS]

Ps. Maybe me being overly cautious, but to avoid any uncertainty and extra work, you can test the cdl actuator function in the spare box by moving it with a 9 volt battery before you install it. I had a used actuator that was dead on arrival, and was able to figure that out before installing it and having to redo a bunch of work.

 

[bicycleagent003]

Ps. Maybe me being overly cautious, but to avoid any uncertainty and extra work, you can test the cdl actuator function in the spare box by moving it with a 9 volt battery before you install it. I had a used actuator that was dead on arrival, and was able to figure that out before installing it and having to redo a bunch of work.

Right on. Thanks, I'll try that. Much appreciated.

 

[jonheld]

- Am I going to lose/spill any ATF out the backside of the torque converter? I'm hoping no.

You're not going near the torque converter. It's just an output shaft from the transmission and there should be no fluid leakage, assuming the output shaft seal isn't leaking.

- How do I ensure that the CDL is in the proper position on the temporary T case I am swapping in?

Not necessary unless you're taking the transfer case apart or removing the actuator.

Please feel free to throw any tips my way. I've never done this before and I'm a bit intimidated by the project. Any advice would be happily accepted.

If your engine mounts are in good shape, you can remove the transmission crossmember bolts and lower the driveline with a floor jack and let it hang. This makes getting to the bolts easier. Just check under the hood and make sure nothing is getting stretched.
After removing all the bolts, the transfer case will remain attached to the transmission. There are pry points between the 2 that you use to break the FIPG seal. There are locator pins on the TC and mating surface of the transmission that can pop out and be repositioned as needed.
The transfer will hang on the output shaft of the tranny and will slide backwards about 3" before it lets go. Have a floor jack and at LEAST 1 other pair of hands to steady it as it comes off as there is no flat bottom and it will want to roll off the jack. It's freakin' heavy.

Installation is the reverse, but make sure both mating surfaces are clean and the locator pins match. Use the red Toyota FIPG on the mating surface of the tranny before installation.
Position the shift linkage forward on the transfer case as you raise it into place. You won't be able to reposition the linkage afterwards.
Follow the FSM for torque specs.

NOTE: While the TC is removed, take the time to re-wrap the 4 connectors into a harness. Likely, the original wrap has deteriorated.

 

[Malleus]

What he said.

I just did this several months ago, and I'll never remove a transfer case without the transmission again. Far too much of a PITA. Much easier to bolt them together while they aren't under the truck and then lift both in place. Clocking the transfer is a true PITA. The lift carries all the weight, so the pair is no more work than either separately, in that regard.

I removed the spinner from my floor jack and replaced it temporarily with a piece of wood. More balancing area and no risk of breaking anything I care about.

Oh, and make all the harness connections BEFORE you bolt them in place. You cannot see the top of the case(s) when they are bolted in. And mark the connectors before you pull them off. There are two that use the same connector housings (genius, that).

 

[jonheld]

I just did this several months ago, and I'll never remove a transfer case without the transmission again.

IMO it's really not that bad to R/R just the transfer case. That said, I did have to do the swap 3 times due to unforeseen issues, so I got pretty good at it.

 

[CharlieS]

I found the cheap Harbor Freight transmission scissor jack to work well for this job. It isn't very well made, but I got a lot of use out of it before the cheap pot metal cage for the bearing exploded (part not available separately). It sure beats bench pressing the transfer case. The only trick is to make sure the vehicle is high enough to wheel the transfer out including the height of the lowered jack.

 

[Malleus]

I looked at that really hard for a minute, then I decided to make a cradle for the transfer case from wood scraps, bolted in place of the spinner on the floor jack. And, since I don't have a lift, the frame was 3 inches higher off the ground to allow me to slide the transmission under it, bellhousing attached (because I really didn't want to torque those bolts lying on the ground). This made reaching the transmission with the transfer case more of a chore than it should have been, but it did provide needed extra work room to move around, so a mixed blessing/curse.

Truth be told, I did agonize over whether to install them separately, or assembled, and chose the wrong solution.

This job would not have been so frustrating if there was at least ONE FLAT SPOT on the bottom of the transfer case. I mean really, how hard would that have been?

A really decent transmission jack in on my Christmas list

 

[bicycleagent003]

Thanks so much, guys. My buddy and I got 'er done yesterday. We swapped out the original T case for the temporary case I bought while I regear the original case. Man, one of those electrical connectors was a really PITA. We spent 45 minutes trying to disconnect the large white connector near the back top of the T case. It was miserable. I was able to handle installing the temporary case by myself after my buddy had to get going. I'm expecting the swap next time to be much easier, of course. Part of me is wondering if I should take out the trans and T case together to replace my rear main seal that's leaking. That sounds like a lot more work. I don't know if I'm up for that.
Thanks again for the tips.

 

[dallen341]

Why not do the gear swap in the temp T-Case and swap it in? One and done.

 

[Malleus]

Pulling and reinstalling the A343F is the easiest transmission job I've ever done. The transfer case gave me fits, but the transmission went in so easily, I had to check it twice to make sure it was really mated properly.

The only bugger was breaking the nut on the return line loose. Even with the exhaust out of the way, it's a PITA with common tools.
You really need the Toyota extended crow's foot; it's well worth the cost. 09630-22020 (17-mm crow's foot); note: you cannot use a generic crow's foot - they're too short. This one is specially designed for the cooler line fittings on the transmission and the power steering high pressure circuit lines. There is also a 14-mm version. Pieces 1 and 2 of a set of two.

They used to look like this:

special thanks to @dmamj for this and the other awesome tool porn.

Current versions are similar to conventional crow's foot adapters, but longer.

But, now that you have the cooler lines off, you can flush them, and the cooler, for a really clean transmission!

Oh, and spray those connector housings with CRC plastic safe cleaner; you thank yourself later.

 

[bicycleagent003]

Pulling and reinstalling the A343F is the easiest transmission job I've ever done. The transfer case gave me fits, but the transmission went in so easily, I had to check it twice to make sure it was really mated properly.

The only bugger was breaking the nut on the return line loose. Even with the exhaust out of the way, it's a PITA with common tools.
You really need the Toyota extended crow's foot; it's well worth the cost. 09630-22020 (17-mm crow's foot); note: you cannot use a generic crow's foot - they're too short. This one is specially designed for the cooler line fittings on the transmission and the power steering high pressure circuit lines. There is also a 14-mm version. Pieces 1 and 2 of a set of two.

They used to look like this:
View attachment 3738947
special thanks to @dmamj for this and the other awesome tool porn.

Current versions are similar to conventional crow's foot adapters, but longer.

But, now that you have the cooler lines off, you can flush them, and the cooler, for a really clean transmission!

Oh, and spray those connector housings with CRC plastic safe cleaner; you thank yourself later.

Wow, thanks for the tips. Hmm... maybe.
Does that CRC cleaner help in removing tight connections? Or it's just for cleaning? Do you spray it inside the connectors once you have them open? I'm intrigued.

 

[bicycleagent003]

Why not do the gear swap in the temp T-Case and swap it in? One and done.

Yeah, I thought I'd do that initially. Then I reflected that I know my T case is quiet as a mouse and works great. The used one I bought? That's a question mark.
After I got the temporary one installed, I pulled the drain plug. I was actually thinking I'd just run whatever crummy oil was in in, because who cares, right? A couple of ounces of water case out first (!), then a quart plus of very, very filthy looking gear oil. I'm glad I drained it, to say the least. I put in the used synthetic Valvoline gear oil I had drained from my T case the day prior, which only has something like 15K miles on it. All is good, it's working fine.

 

[Malleus]

Wow, thanks for the tips. Hmm... maybe.
Does that CRC cleaner help in removing tight connections? Or it's just for cleaning? Do you spray it inside the connectors once you have them open? I'm intrigued.

Yes, it will loosen stuck connector housings; IME, they stick together becasue of trash intrusion - once they're clean, they pop open as advertised. After you disengage the halves, spray it liberally inside and out until the housings look new again.

I buy it by the case.

 

[Malleus]

Also, deoxit cleans the terminals ends pretty well; not as good as crocus cloth, but better than you'll find them after 30 years.

 

[bicycleagent003]

Also, deoxit cleans the terminals ends pretty well; not as good as crocus cloth, but better than you'll find them after 30 years.
View attachment 3738973

Thanks for the suggestions. Much appreciated.

 

[Malleus]

This guy actually reviewed the pan seal cutter and a Lisle (poor) copy (3:20 to 4:20).

He must have really small hands, because I can hide that thing in one of mine.

I think mine's a Tillman (but it's the same as the Toyota OEM SST from OTC):

the string of numbers after the J-37228 part number is the Toyota number.