Rear Main Seal

[athawk11]

A serious question for serious Willys men.

I'm replacing my rear main seal. I jacked it up bad while searching for that knock last year. If you don't believe me, ask Lee. He has photos.

I removed the old seal and found it to be bone dry. Sahara Desert Dry. The bearing and crank are getting oil, but the seal doesn't have a drop of oil on it. Thoughts? How can this be this dry?

My leak appears to have come from the dowel area. I'll work hard to eliminate as much of this as I can.

I use rope seal.

[Deleted]

Hmmmm..... I'm trying to think how the rear main cap looks... But your right, I don't believe the main seal can run dry without doing damage....

[athawk11]

Hey Gary,
Missed a call from you last night. Must have been in the crapper. This is a photo of the rear main area. This is a different engine. You can see the neoprene seal. The crank has a disc on it that rides in the gap just in front of the seal. It would act as a oil slinger (I'm guessing) to keep large amounts of oil from hitting the seal. It just seems odd that the oil seal is bone dry.

[Deleted]

Yo Tim!

Just got your voicemail, and called you back.... Reckon you ate something that didn't agree with ya?? Lol!!

[Haines Garage]

I am going to take a stab at it. Does that rear cap have a tube into the oil pan ?
Here we go....

[athawk11]

This bearing cap does have the drain tube. After all, it is a GPW engine.

I use it as a handle.

Tim

[Deleted]

Ok, Tim. I'm stumped......(not stump broke, Bo )....Just stumped.....

MINNY-SOTA LEE AND OILY HEEELLLLP!!!

[Deleted]

I guess I'm no help here. Never took one apart to see if it was dry or wet. Wet most likely would be leaking. If it was too dry, I would expect to see it coming apart and chunks around. So, maybe it's perfect! I don't know. Oilly

[Haines Garage]

I'm reading back through this again. You had a leak at the rear main on your running Jeep, and to fix the leak you found the rear main seal....the rope one, bone dry....
You pullin a Haines Garage Fargin Trick Question Icehole ?

[Haines Garage]

Oh Annnnnnnnnddddddd you also asked the serious Willys guys.
Your problem seems to be with a F O R D product.....go figure.....

[Deleted]

Well if it was leaking it would be wet, it's not. Tim also said it was the side rubbers leaking. If it were mine I would redo the side rubbers and try it!, after all, that's fairly easy. Also, yes the disc is an oil slinger!..............

[Haines Garage]

Those rubbers.....hard to put on, easy to take off !!!

[Deleted]

May 29, 2015 16:36:02 GMT -5 Haines Garage said:

Those rubbers.....hard to put on, easy to take off !!!

And one time use only!!!

[athawk11]

You guys aren't talking Willys rear main seals anymore...are you?!

When I pulled the bearing cap last year, I made enough of a mess out of the rope seal that I had no choice but to replace it. Doing this without pulling the crank is a task to be avoided. I don't wish this hell on anyone. The hardest part is over. ( getting the seal over the crank). It was such a bitch that I had to take a couples day away from the damn thing.

Tim

[Haines Garage]

May 30, 2015 20:08:19 GMT -5 athawk11 said:

. It was such a bitch that I had to take a couples day away from the damn thing.

Tim

Yeah....I like those " couples days off" myself LMFAO!!!!!

[Deleted]

Tim...so you lower the crank in the rear as much as it will go, right? How much of a gap did you have then?

Afterwards, once you threaded the new rope seal around, how did you flatten it and stuff? Using arm strength against the crank shaft several times?

[jeffwho]

May 30, 2015 0:19:02 GMT -5 @gmcjr said:

May 29, 2015 16:36:02 GMT -5 Haines Garage said:

Those rubbers.....hard to put on, easy to take off !!!

And one time use only!!!

OOOOOOOOOOOOOOOOH. So that's what happened ...oops

[Deleted]

That rear main cap is such a pain on the engine stand, that I wouldn't attempt it underneath a Jeep. Those rubber tubes are a joke. Poor design. I hope it works for you and doesn't leak worse. Frankly, every Jeep I've ever owned, leaked all over the place. You have to cop a attitude about leaks. Identify and bad one from a good one. Normal from abnormal. A clean perfect Jeep is either out of oil, or never got filled. I'm amazed at a TJ Wrangler, they seep a little, but really don't leak. They don't call me Oilleaker for nothing. Standard operating procedure is cardboard, and jug of old cleaning solvent, and rags you scoot around on the garage floor where needed. English sports cars and motorcycles leak just as bad. They even have a rally named: The Oil Spot Rally. Nice parks with car shows include a drip towel in your packet for the show. What does that tell you? Ever see a rear main seal that is a scroll? No kidding, a MG midget's rear main seal is a reverse thread that screws the oil back in while running. Wait until you park it on a steep hill. Oilly

[jeffwho]

I'm going to copy this quote out and pin it to my garage wall - I'm a slow learner, so maybe this will help me get over my leak paranoia.

[athawk11]

Well, I did this rear main seal swap..for the third time on this engine.

First time...Neoprene seal. Disaster.
Second time...Rope seal. Decent results until I ruined it when looking for an engine knock.
Third time...Rope seal. This is now leaking worse than it was after I ruined the seal on the second round.

I'm not sure why. I'm going to pull it apart again. The one thing I noticed when installing the cap was one of the rubber dowels compressed nicely into the passage. The other did not compress very well. Almost as if it were a larger diameter. But now I'm thinking it may not have seated fully.

This is really beginning to piss me off.

Tim

[Deleted]

I feel for you Hawky. The job just plain sucks to do. Oilly

[Ryan_M]

If nothing else I am feeling much less inclined to dive into mine chasing a "minor" leak. I can deal with a half dollar sized puddle every morning at least until Tim gets this procedure down to a science and posts the expert tutorial.

Joking aside, it's pretty annoying to get that pissed at what's supposed to be an enjoyable hobby. I'm there at least once a week or so.

[Haines Garage]

Nothing worse than doing it thrice. You will get it. I had the same problem with the two sets of rubbers I had. The smaller diameter is what went into the chain drive L134. Are you using RTV on the mating surfaces? Is there a possibility that the Crankshaft has a groove wore into it?

[athawk11]

Upon further inspection, I believe I spun the seal. The dowels were well sealed. ( to the point where I had a very hard time pulling the cap). The rope had spun. The seam was 90 degrees from where it was suppose to be. I don't know if it was spinning with the crank, but it wouldn't surprise me. I got a little aggressive with the RTV on the mating surface next to the rope seal. It gooshed into the rope...which is a no-no. The two pieces of rope were stuck together.

I learned a trick on the 503. A fellow used a bit of Permatex 2 in the seal groove on the bearing cap prior to setting the rope seal. This should help eliminate another spinning seal. I'll let it set up for a day before I reassemble.

HG, no grooves in the seal surface. It looks almost like the surface was sleeved, but I'm not sure how they could have done that in this location.

I will say, it is not ideal to set the rope seal without pulling the crank. You can't seat the upper seal deeply in the upper seal groove, but as hard as it is to pull that seal in, it's probably compressing fairly well.

I'll set the cap and oil pan tomorrow. I'll test drive it on Wednesday. Hopefully, I'll have better news.

Tim

[Deleted]

I can't imagine how in the world you are cutting off the excess of the rope, up in that terrible place to get to. They are hard to do in a engine stand, before you install the crank. Tell us your technique. Oil