Transfer case rear seal leak (1 Viewer)

[OwnerCS]

There is a ratio on the bottle, I don't recall off the bat.

I guess the Amazon version comes without instructions.. LOL. I found this old BITOG post that is 1.333 oz per quart as @2001LC noted above.

 

[OwnerCS]

Looking back at a picture from early Feb 2021, I think the seal was starting to weep a bit.

Soon after this picture was taken this was covered in mud on a monthly basis. I would clean up after each mud adventure. This problem has been a while in the making.

 

[nissanh]

Thank you @nissanh for the very detailed write-up and parts list.

My only question at this point is did you have any difficulty reinstalling the rings in this picture? I've gotten around this in the past by using some tacky grease to parts like this in place during reassembly. Or are these the shims that were secured with super glue?

Thanks again and I'm sure I will have more questions as I start digging deeper into this.

I used superglue! Yes, I'll be more than happy to help!

Make sure to align the oil pump arm to the main transfer case body. If two half's don't lign up, DON'T tight the bolts.. remove and inspect the two spacers and oil pump arm are all in correct positions.

 

[Mauser]

You pull the rear half and then pull the the axle (output shaft) to replace the oil seal. I document this repair (link below). Also replace the bearing. Use OEM parts.
That was my first time doing this and is doable without much effort.

Transfer case rear output shaft oil seal and bearing removal and installation

Disclaimer: Author is NOT responsible for any problems that you may run into. This is Demonstration purposes ONLY. Special Thanks to 2001 LC in the forum Parts needed: Oil seal and Bearing (USE OEM only: MAKE SURE YOU INSTALL BOTH) Bearing $ 40.00 Oil Seal $ 20.00 FIPG (I used TOYOTA Black)...

forum.ih8mud.com

I used this write up a couple months ago to replace the bearing in mine. It is a pretty easy repair. I also used super glue.

 

[OwnerCS]

Here's a link to the ATP product use chart. I'm giving it a try.

http://atpautomotive.com/wordpress/wp-content/uploads/2016/05/ATP-Chemical-Additive-Brochure-2016.pdf

 

[2001LC]

With 244,000 miles, I guess it's time for a transfer case seal to start leaking. After each off-road trip, I check everything to look for issues. This week I found a drip from the rear seal. This is the only t-case leak at the moment. I change diff and xfer case fluids often. This just started after last weekend's adventure.

Any suggestions for replacing the rear seal or is a full t-case removal and reseal in order?


View attachment 2849568

AT-205 may help, as it puts back what plasticizer time leached out of the rubber. Which time span, is shortened with standard gear lube gunk build up on seal. We then cleaned off with synthetic lubes/oils and leak reveals. AT-205 effective swells seal back to factory size, by soaking in plasticizer.

That's quite a leak. Leaks that bad. Are more often from: Long term bad fluid and building gunk on seals. Which may have errodong seal surface and damaged bearings. We then flush with synthetic gear lube, which cleans the gunk revealing bad seal. AND/OR Bad bearing causing vibration/wobble.

Let's hope AT-205 does the trick and bearing okay! But you seem more than capable R&R the bearing if needed.

AT-205 arrived today from Amazon. I guess 3.5 tbs for the 1.4 quarts in the t-case?

Bottle is 8oz, which states for 6 qt. 8oz / 6qt = 1.333oz. 1.4qt cap. TC x 1.333oz = 1.867oz (round up to 1.9-2 oz. is okay) added to TC. If that's what 3.5 tbs =.

Here's a link to the ATP product use chart. I'm giving it a try.

http://atpautomotive.com/wordpress/wp-content/uploads/2016/05/ATP-Chemical-Additive-Brochure-2016.pdf

ATP chart state 1.5oz to 1 qt. Than next column states: approximately 1/6th of the bottle (1.333 oz.). Fact is when dealing with such small amounts, we lose some in measure and pour container(s). So a little more to compensate is fine.

If i can't pour directly in from my 1 zo. measuring cup, like in T-case. I pour into gear lubes bottle as I refill transfer case with gear lube. Here again I add just a tad extra for lose.

I have done second dose a year later, which worked out for me. But AT-205 support stated to me: not needed or recommended for another 7 to 10 years.

 

[OwnerCS]

AT-205 may help, as it puts back what plasticizer time leached out of the rubber. Which time span, is shortened with standard gear lube gunk build up on seal. We then cleaned off with synthetic lubes/oils and leak reveals. AT-205 effective swells seal back to factory size, by soaking in plasticizer.

That's quite a leak. Leaks that bad. Are more often from: Long term bad fluid and building gunk on seals. Which may have errodong seal surface and damaged bearings. We then flush with synthetic gear lube, which cleans the gunk revealing bad seal. AND/OR Bad bearing causing vibration/wobble.

Let's hope AT-205 does the trick and bearing okay! But you seem more than capable R&R the bearing if needed.

Bottle is 8oz, which states for 6 qt. 8oz / 6qt = 1.333oz. 1.4qt cap. TC x 1.333oz = 1.867oz (round up to 1.9-2 oz. is okay) added to TC. If that's what 3.5 tbs =.

ATP chart state 1.5oz to 1 qt. Than next column states: approximately 1/6th of the bottle (1.333 oz.). Fact is when dealing with such small amounts, we lose some in measure and pour container(s). So a little more to compensate is fine.

If i can't pour directly in from my 1 zo. measuring cup, like in T-case. I pour into gear lubes bottle as I refill transfer case with gear lube. Here again I add just a tad extra for lose.

I have done second dose a year later, which worked out for me. But AT-205 support stated to me: not needed or recommended for another 7 to 10 years.

I used a syringe to squirt it into the t-case opening after I had drained and before refilling. It seems to have slowed the leak. Though I'm not sure this will be the fix.

I really think that I'm the culprit from high-centering the slip yoke part of the drive shaft while climbing up this side of a mountain. I normally descend this part. We decided to get brave and run it in the opposite direction. I can see where others have high centered coming out of the switchback and going over the first hump in the picture.

I believe the hill thrust the driveshaft into an unnatural position and put pressure on the t-case shaft and seal. In talking to my local LC guru, he said to make sure that I didn't bend the driveshaft. I'm not getting any t-case vibration that would be coming from a bent drive shaft.

I like the straight drive shaft and not having to worry about a center diff bearing (pictured below) and double cardan joint.

But then I can see how a center diff bearing may absorb some of the shock that goes directly into my t-case when I start climbing the rough stuff.

 

[2001LC]

"picture from early Feb 2021" This was before hit to slide yoke, I thought!

Hit hard enough perhaps you did damage seal. Yoke should show signs of hit, and I would think you'd get vibration..

 

[OwnerCS]

AT-205 appears to have slowed the leak by 50%. I've only driven it 70 miles. I wonder if it will improve over time.

 

[2001LC]

AT-205 needs 5 hours of cumulative run time.

 

[OwnerCS]

AT-205 needs 5 hours of cumulative run time.

Yay. It's trending in the right direction.

 

[2001LC]

I've been hopeful, that it just a case of dry seal. But I have seen AT-205 work, than hours later leak back. That means seal damaged.

If you indeed damaged by hitting this would likely be the case. But I'd really think propeller shaft/slide yoke would show hit and very likely vibrate, with hit that hard.