Need To Replace Rear Transmission Seal

[terceltoy]

I replaced my trans/diff unit and now the rear seal on the transmission is leaking, not bad, but leaking.

Can this seal be replaced without disassembling the transmission? I have a seal removing tool (kind of like a claw hammer) but the seal is inside (recessed) the dust cover (?) and seems it would be hard to reach.

I searched the forum but couldn't find anything on this.

Terceltoy

[xirdneh]

just did one a week ago. pulled the driveline. removed dust shield on end of tranny (just wiggle it off). popped old seal out using screwdriver (some drill two small holes in seal on opposite sides and put screws in them then grab the screw heads with vise grips and pull)
tap in new seal evenly

[Petros]

if the leak is not too bad you might try adding seal conditioner in the trans. It is an adative the softens old stiff seals and sometimes will stop a leaky one. easier than replacing the seal, but the rear one is not a bad job to do, you just have to remove the drive shaft to get to it.

[terceltoy]

"removed dust shield on end of tranny (just wiggle it off)"

I thought maybe the dust shield came off.

Thanks for the help.

[ARCHINSTL]

xirdneh -
OK - I have discovered a leak from the rear trans seal. Oddly, it leaks only when the car is on a nose-up incline of 15-20 degrees - never on level ground. The leakage is maybe 10-15 drops overnight. This is after draining and filling it 250 miles ago.

From your preceding post it is not a big deal - right? I presume you dropped the shaft per the FSM?

Would you now recommend finding a tube (like a PVC pipe) of appropriate size to tap in the seal, or stay with your method of carefully using a flat punch all around it? Would you recommend buying two seals in case I booger the first one?

When the shaft was removed, did a lot of oil come pouring out? Should I raise the back of the car higher than the front to maybe eliminate this? Should I improvise a plug or just go ahead and drain the trans prior (less messy?)?

I may do this in concert with replacing the really worn center support bearing - dunno yet, although it would be expedient.
Thanks!
Tom M.

[4wdchico]

Just replacing the rear seal on the tailshaft housing (TSH hereafter) of the transfer case, what others are calling the rear trans seal, may be a short lived solution to a leak. My car developed a leak less than a year after replacing the seal in question. I found a really good former 'yota line tech in Boulder City NV to fix my car while I was on the road. What was the underlying issue turned out to be the non-replaceable u-joints in the drive shaft assembly were starting to fail and had gotten pretty notchy. This situation, in concert with a sloppy rubber bushing in the center drive line assembly support bearing, had caused the sleeve in the rear of the TSH, in which the front yolk of the driveshaft rotates, to wear out. So I needed a rebuilt driveline. A good driveline shop can do this for about $400, it costs this much as the whole thing has to remade. The upside to this is that you end up with a new and rather pricy center driveshaft support bearing installed on a driveshaft that can have it's u-joints replaced if need be. Sorry, but I bought the last two remaining rear tailshaft housing bushings from the local 'yota dealer. The parts fellow that told me this was pretty adamant that these were the last that Toyota would ever sell for our cars. YMMV. But I'm fairly sure that a good tranny shop could get you an aftermarket bushing. The bushing can be replaced fairly easily with the whole tranny/diff/ transfercase in the car. That is if you have your car on a lift while doing this. Groveling on the ground while doing this may provoke a Tourette's moment or three.

In light of all of the above, I'm going to suggest that anyone who is having this particular seal problem inspect their driveshaft well for bad/notchy u-joints when it is out of the car. Check the center support bearing in the middle of the DS assy. also. Then, after the seal has been removed, reinsert the front of the front driveline yolk back into the rear of the TSH and feel for radial play between the bushing and yolk. Any more than just a little radial play and a new seal only repair will be short lived.

FWIW: I bought one of these tools: http://www.napaonline.com/Search/Detail ... 0006402328 to pull the seal when I did the job myself the first time. It worked like a champ. It was a whole lot cheaper a couple of years ago.

[ARCHINSTL]

This is interesting...While looking for info on this, I encountered exactly what you are talking about, but in regards to other Toy vehicles - don't recall if Celica/Cressida/Truck.
I was hoping this might not be applicable to our cars...
I guess I'll follow your advice - and hope for the best...
Thanks.
Tom M.

[ARCHINSTL]

> See new Parts Forum thread for some OE part #s for this and some other stuff: https://tercel4wd.com/forums/viewtopic.php?f=3&t=5743
> See https://tercel4wd.com/forums/viewtopic.php? ... ken#p42177 for info on drive shaft rebuilding.

Also - to 4wdchico - you mention that the TSH bushing can be replaced "fairly easily with the whole tranny/diff/transfercase in the car." The FSM mentions that the extension housing must be removed and heated to 212 degrees F and then the bushing is pressed out (actually in towards the front of the housing) and then the new one is quickly pressed in.
What is your method to replace it in situ? Looking at the diagram, the FSM method looks like the only way to do it - and then with some kind of big press.

Also on this bushing - Butler advised that there are now only 4 left in the entire USA...
Tom M.

[4wdchico]

> See new Parts Forum thread for some OE part #s for this and some other stuff: https://tercel4wd.com/forums/viewtopic.php?f=3&t=5743
> See https://tercel4wd.com/forums/viewtopic.php? ... ken#p42177 for info on drive shaft rebuilding.

Also - to 4wdchico - you mention that the TSH bushing can be replaced "fairly easily with the whole tranny/diff/transfercase in the car." The FSM mentions that the extension housing must be removed and heated to 212 degrees F and then the bushing is pressed out (actually in towards the front of the housing) and then the new one is quickly pressed in.
What is your method to replace it in situ? Looking at the diagram, the FSM method looks like the only way to do it - and then with some kind of big press.

Also on this bushing - Butler advised that there are now only 4 left in the entire USA...
Tom M.

I was not there when The Bushing was replaced. The tech said that the old bushing came out fairly easily & the new one went in with a reasonable tightness. He described the process in detail and it seemed like not a big deal. Given your input on the FSM procedure, I guess that I might go as far as applying boiling water to the outside of the region inside of which the bushing is fixed in place, to help with extracting said bushing. Then more boiling water again to assist with the install of the new bushing and I would also pull the very cold bushing from a freezer. My guess is that with this great a thermal differential betwixt the TSH & bushing that the bushing would very likely slip right into place without being driven at all. Just in case, I would have a pre-selected socket and extension from my 3/4" drive socket set on hand with my dead blow hammer standing at the ready.

But hey, if you would prefer pulling the TSH to do the above, please let us know how it went.

[ARCHINSTL]

So I presume the tech inserted some kind of puller and extracted it that way - as opposed to the FSM method of driving it through to the front of the removed housing? Wonder what he used?
If so, this is definitely easier than the FSM method!
Tom M.

[4wdchico]

So I presume the tech inserted some kind of puller and extracted it that way - as opposed to the FSM method of driving it through to the front of the removed housing? Wonder what he used?
If so, this is definitely easier than the FSM method!
Tom M.

The tech thought that the old bushing was so easy to remove because of all of the abuse it suffered from the messed up driveline assy. IIRC you may be able to get onto the back end of the bushing with one, or preferably two, needle nosed vice grip pliers and wiggle that sucker out. What have you got to loose?

I'm pretty sure that you will be getting a rebuilt driveline once you see what the condition your u-joints are in. I'll bet that they are quite notchy .

[ARCHINSTL]

Part of my confusion is because I just now realized the shaft on the end of the front drive shaft is internally-splined and that it therefore fits around the trans output shaft; ergo, there is a space between the output shaft and the bushing. D'oh...
So, while the bushing is driven into the TSH, it makes no contact with the output shaft. Another D'oh...

Atec makes a tool for some cars which is a really thin sleeve with external "prongs" on the end that slips between the output shaft and the bushing. A threaded rod is then tightened against the shaft's center and the bushing pulls right out. I wonder how much space there is between the shaft and the bushing?
The new bushing is driven in using a tool similar to the Toy SST, which is essentially a pipe with a shoulder and a thick end for the press.

I hope I'm not being obtuse here, but...I can see how the bushing might be "easy" to wiggle out if it has the wear you describe. But how did the tech get the new one in? Did he use a "pipe?" Maybe a thickwalled PVC pipe?

Incidentally, I also froze the bushing as an experiment; it started at 37.04mm and finished at the same (my freezer is set at 26-28 degrees).
I'm all for doing it myself and would of course rather not remove the TSH, as it is kinda involved.

Thanks for the advice! Lots of food for thought.
Tom M.

[Highlander]

Tom- You need a much greater difference in temperature than that to help you out. go to the supermarket, and buy some dry ice (Solid CO2) which exists at -78* C (or -109F). That should give you great enough delta T to shrink the bushing by ~0.002" (0.05mm) or so. I have the advantage when it comes to things like this because I regularly work with materials between the temps of -269*C to +250*C (-469*F to 500*F), and have access to Liquid Nitrogen (75.8 K or -196C) on an ongoing basis to shrink (or swell) anything that i need to shrink fit.
Put the bushing on a piece of foam inside a small cooler (Lil playmate size or so) and put the dry ice on top of the bushing (be sure to wear gloves-it'll burn you quickly) and put the top of the cooler on. Give it 5-10 minutes, carry the cooler out to the car, slide it under, pull the bushing out (again with gloves, silly) and install it directly, it should be a nice slip fit, but only for a little while, so don't dawdle or F up.
Just a hint from the cool side of things....

[ARCHINSTL]

Wow! Thanks!
I must confess, while I've been aware of dry ice, I had not considered it.
Today is a big day for "D-ohs" for me - my forehead keeps getting flatter...
.05mm should be enough to do it, I'd think, as long as it doesn't distort any and the hole in the TSH is still nice and round.
It will be a week plus before I get into this, though. In the meantime, some of you may want to get the other four bushings... 'Member, next time they come from Japan.
Tom M.