Best rear seal?

[clinem03]

I've been dealing with all sorts of oil leaks and have taken care of most of them, except the rear seal. I'm dropping the transmission next week and plan to take advantage of the access to the rear seal to replace it. I picked up a felpro two piece seal but have found a few other threads that state that they might not be the best seal.

What is the absolute best brand to use for the real seal?

76 wagon, original 302, original 3 speed manual transmission.

 

[Rustytruck]

the factory rear seal was a 2 piece rope seal you will have to drop the oil pan and remove the rear main bearing cap to deal with it. the cap has a sharp pin the stabs the rope seal to keep it located. if you use any other type of seal you have to punch this pin out and not reuse it. so your not just removing the tranny. later model 302's used different seals some 2 piece and some one piece. I don't know whats interchangeable. this is not an easy job in the truck. I would look for some u-tube videos before getting started. I would rather pull the motor than pull the tranny and transfer case for this job. once you pull the motor you can do allot of other things like cleaning painting new gaskets everywhere and not just the rear seal and you can give the engine bay a good cleaning while you have access.

 

[clinem03]

the factory rear seal was a 2 piece rope seal you will have to drop the oil pan and remove the rear main bearing cap to deal with it. the cap has a sharp pin the stabs the rope seal to keep it located. if you use any other type of seal you have to punch this pin out and not reuse it. so your not just removing the tranny. later model 302's used different seals some 2 piece and some one piece. I don't know whats interchangeable. this is not an easy job in the truck. I would look for some u-tube videos before getting started. I would rather pull the motor than pull the tranny and transfer case for this job. once you pull the motor you can do allot of other things like cleaning painting new gaskets everywhere and not just the rear seal and you can give the engine bay a good cleaning while you have access.

Whoa! I didn't think it was that involved. Going to look up some you tube videos now. Thanks!

 

[dougsride]

I have done a couple two piece seals in the later motors with felpro seals. It's a messy but not a hard job. That being said unless your seal is bleeding I wouldn't mess with it. To be honest I think they don't lend well to being replaced outside of pulling the crank. But if it is bleeding you have nothing to lose by replacing it in the frame.

 

[clinem03]

I have done a couple two piece seals in the later motors with felpro seals. It's a messy but not a hard job. That being said unless your seal is bleeding I wouldn't mess with it. To be honest I think they don't lend well to being replaced outside of pulling the crank. But if it is bleeding you have nothing to lose by replacing it in the frame.

I watched a few videos and it really doesn't seem that hard to replace it in the truck with the transmission on (from the oil pan side). It's leaking a lot so I'll have to do something. I plan to tackle the job here in the next week or so

 

[blubuckaroo]

There are a number of good videos on Utube about replacing the rear main seal on a Jeep 4.0. The process is very similar to a Ford engine.
Just be sure to clean the cap mating surfaces, oil free, with acetone or Chem tool, then use an anaerobic sealant from the seal to the edges of the cap.

 

[jamesroney]

I watched a few videos and it really doesn't seem that hard to replace it in the truck with the transmission on (from the oil pan side). It's leaking a lot so I'll have to do something. I plan to tackle the job here in the next week or so

The youtube video from nashville Bronco is not good.

They show someone replacing an improperly installed 2 piece lip seal with another 2 piece lip seal.

Someone installed the first lip seal (long before the video was made) without removing the anti-rotation pin for the rope seal. It's no wonder that it leaked. Then someone took an abrasive grinder and ground the pin IN THE CAP. This is flirting with disaster. One small slip, and you will nick the cap and create a leak path. You are better off driving out the pin and sealing up the little hole.

It's a minor miracle that the lip seal works at all since it's running against a knurled crank shaft. I like to polish out the knurl if I have the crank out.

On my last 289 build, I just bored the back of the block for a late model 5.0 one piece seal, and machined off the crank flange. That one didn't leak.

When you pull your main cap, check the bearings. I usually pull all of the main caps for inspection, and let the back of the crank fall a little bit. It makes it easier to get the seal in and out, but it will also tell you the condition of the crank. I usually inspect all of the rod bearings as well. So far, EVERY time I've done it...I've needed new bearings. Cheap and easy to do in frame.

 

[clinem03]

The youtube video from nashville Bronco is not good.

They show someone replacing an improperly installed 2 piece lip seal with another 2 piece lip seal.

Someone installed the first lip seal (long before the video was made) without removing the anti-rotation pin for the rope seal. It's no wonder that it leaked. Then someone took an abrasive grinder and ground the pin IN THE CAP. This is flirting with disaster. One small slip, and you will nick the cap and create a leak path. You are better off driving out the pin and sealing up the little hole.

It's a minor miracle that the lip seal works at all since it's running against a knurled crank shaft. I like to polish out the knurl if I have the crank out.

On my last 289 build, I just bored the back of the block for a late model 5.0 one piece seal, and machined off the crank flange. That one didn't leak.

When you pull your main cap, check the bearings. I usually pull all of the main caps for inspection, and let the back of the crank fall a little bit. It makes it easier to get the seal in and out, but it will also tell you the condition of the crank. I usually inspect all of the rod bearings as well. So far, EVERY time I've done it...I've needed new bearings. Cheap and easy to do in frame.

Funny, as I did watch that video. Thanks for all the tips. When you say to tap out the pin, what's the best method for that?

 

[clinem03]

Funny, as I did watch that video. Thanks for all the tips. When you say to tap out the pin, what's the best method for that?

Scratch that, it looks pretty self explanatory to just tap it out. What are you plugging the remaining hole with?

 

[NicksTrix]

drain the oil and let it sit for a night or so before you pull the pan if you have time. helps let the oil work it's way off the rotating assembly. sucks being under the crank while it's dripping on you.

be sure flywheel bolts have a sealer on them as well while trans is out.

 

[clinem03]

drain the oil and let it sit for a night or so before you pull the pan if you have time. helps let the oil work it's way off the rotating assembly. sucks being under the crank while it's dripping on you.

be sure flywheel bolts have a sealer on them as well while trans is out.

Great tips, thanks Nick!

 

[jamesroney]

Scratch that, it looks pretty self explanatory to just tap it out. What are you plugging the remaining hole with?

I grind the pointy end off of the pin and then put it back in. But a single daub of RTV in the hole would also be adequate.

(Actually, what I did last time was to tap the pin further in, grind off the point, and then tap it back so that it is flush...being super careful not to nick the cap with my die grinder.)

 

[clinem03]

Got the rear seal in today, letting it sit for 24 hours for the anaerobic cure. Fingers crossed it cures my major oil leak at the bell housing. Thanks for all the help along the way!

 

[ared77]

Fingers crossed !

 

[clinem03]

Rear seal is fixed! No more leaks at the bell housing - thank you again for all the help!!

 

[Broncobowsher]

So what seal did you end up using?

 

[clinem03]

So what seal did you end up using?

Replaced the rear main seal (felpro 2 piece) and a 1 piece felpro oil pan gasket. The rear seal was actually a lot easier than I had planned. Came out in about 5 min (after everything was out of the way) and the new one went in in about 20 min. Lots of work around that, but just the rear seal wasn't too bad. Let's hope it holds