6.2L rear main seal replacement

[cucvrus]

Murphy's Law

A few of these points are fact, and nothing is infallible. I never seen more then a drop of oil beneath the truck after running your M1009 and letting it sit for days. I put clean cardboard under vehicles to find hard to find leaks. At the age of a CUCV nothing short of a complete teardown of the engine is going to prevent leaks. If you start fixing 1 you may as well pull the engine and change all the gaskets. This costs lots of time and money. The yoke on the drive shaft is probably the out put shaft leak. It has a plug cap in he end and they leak on occasion. Clean the inside U joint side of the yoke and use a sealer. Or purchase a new yoke and press a new U joint in the drive shaft. I will not put myself in this scenario again. Good Luck with the truck. Quick question is the truck running again? I done nothing to the engine and it drove 6 hours after I changed the sending unit in the fuel tank. The fuel gauge works and that was the entire point of my pulling the tank to begin with. The transmission leak I can't explain. I can't see it. Is it a shift linkage seal leaking? I don't know. Take Care and I hope you have a complete recovery.

 

[ssdvc]

This is over 4 days, both oil and trans fluid.




Seems like the pan gasket maybe leaking, so I see about tightening up the bolts a bit. The rear seal has leaked from day one and I think that is the nature of those seal since these trucks sit for quite some time. I am going to try to replace it at some point, once I can get her running again.

This is a shot of the transfer case seal where the driveshaft to the rear end goes in. The yoke slides in and out on that and the seal is leaking as well. Looks like an easy replacement, if I can do it in place (is that possible?). Anyone have a PN for that seal?



And no, she is still sitting in the garage, patiently peeing on the floor and waiting for me to wake her up. I am delayed a bit because of this:



One week out and still swollen and tender. Sucks to be old !! At least I am now weight bearing (kinda).

And Rick, I have no idea how the water got in the tank. I have to lean towards a bad batch of fuel, because I didn't have any issues on my 6 hour drive home from your place, nor during multiple trips I took after that and before she just quit on me. Everything was running pretty damn good up until then.

 

[ehuppert]

Main seals on the CUCVs ALWAYS leaked. Drove them when they were new. Our Mnt guys would always ask how fast I was running as they would leak oil all over after running for hours at highway speeds!

As for transmission pan gasket. Several years ago I started using duraprene gaskets at work as I got tired of leaky comebacks. Gasket is much more forgiving (crush wise) and is worth the little extra. You also have to make sure the pan holes aren't "pulled" .

 

[SomeNewGuy]

OOF..
I sense an impending verbal bashing in the force headed this way.
View attachment 857027

The TM's are located here:

TM's for the CUCV

Listed below are a number of the TM's for the CUCV trucks. To save them to your computer, right click, select "save as". LO9-2320-289-12.pdf LO9-2320-289-12 Lubrication order for all variants of the CUCV. TM9-2320-289-10.pdf TM9-2320-289-10 Operators manual for all variants of the CUCV...

www.steelsoldiers.com

The TM for the rear-main seal is the -34 manual (specifically page 135, but CTRL+F and searching for Rear Main Seal will find it).
All the manuals that end in 'P' are the 'Parts' manuals.

Go get those manuals and look through them and learn how to read them.

Then the top of the forum has a Search feature:
View attachment 857026

Use that to search for things like 'Rear Main Seal' or any other seal you want to replace, and you'll most likely find the answer.
If after doing that you still need help, let us know.

People here are always willing to help people who want to help themselves, but to avoid the shade some of the saltier members will throw at you (you know who you are), do that stuff first.

Good luck on your project. Send some pics.

This is how a new member should be welcomed.

 

[Squibbly]

Hard to find leaks can become easier to find if you clean the area, let it dry and spray with some athlete’s foot spray.

The leak will leave a trace line through it.

Sent from my iPhone using Tapatalk

 

[ssdvc]

Hard to find leaks can become easier to find if you clean the area, let it dry and spray with some athlete’s foot spray.

The leak will leave a trace line through it.

Sent from my iPhone using Tapatalk

LOL!! I know it stops the inch, but will it stop the leak?

 

[Mullaney]

Hard to find leaks can become easier to find if you clean the area, let it dry and spray with some athlete’s foot spray.

The leak will leave a trace line through it.

Sent from my iPhone using Tapatalk

.
Real similar to finding vacuum leaks using ether...

Then when you have a leak confirmed and the motor speeds up - a few squirts of oil on or on the spot around an intake manifold - firms it up even more.

 

[SnowPlowed]

Well I was real slack on following up with this post but I did the rear main seal, transmission pan gasket, oil pan gasket, and oil cooler lines. Completed the work back in May of 2022. I appreciate all the help for folks on here.

 

[cucvrus]

Good Job. When things slow down weather wise, I would recommend changing the head gaskets.