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Oil Leak

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Category: CJ-2A Discussion Area
Forum Name: Tech Questions and Answers
Forum Description: CJ-2A technical questions here
URL: https://www.thecj2apage.com/forums/forum_posts.asp?TID=44691
Printed Date: 28 Mar. 2024 at 9:30pm
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Topic: Oil Leak
Posted By: Lhead
Subject: Oil Leak
Date Posted: 03 May 2019 at 4:58am
Finally after wading through 10 miles of Calif DMV red tape, I can drive my CJ2. The engine has been rebuilt. I have maybe 75 miles on it so far, mostly very short drives (2-3 miles). After a longer drive (5-10 miles), it pukes oil after stopping. Seems to puke out a couple ounces from the drain hole in the bell housing indicating a rear main leak. My question is, is there any chance the rear main seal will settle in after a few more miles or am I dreaming? It is a rope rear main type seal. Thanks, Larry



Replies:
Posted By: willyt
Date Posted: 03 May 2019 at 1:05pm

My jeep sat for a few years before I purchased it. It had a small seal leak, which got bigger, I also hoped would go away. It didn't. I tried a can of seal leak stop stuff, didn't phase it. Mine was a two piece neoprene Victor seal. The stop leak stuff may work better with a rope seal, but the only good coming out of it will probably be the stores profit line. lol



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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: Lhead
Date Posted: 03 May 2019 at 3:35pm
I'm afraid you are right Willyt. I was really careful putting the seals in, leaving a bit exposed to compress. Same with the rubber plugs that seal the rear main cap. Obviously something didn't seal. I'll drive it for awhile like it is mainly because I don't have time to fix it right now. Looking at my profile picture compared to yours, It looks like I chopped, channelled, and widened my jeep through the magic of photo editing. I guess I'll try reducing the size of the pic again to get the right proportions. Thanks, Larry

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Larry
46 CJ2A L134
33 Ford Merc Flathead


Posted By: willyt
Date Posted: 03 May 2019 at 4:45pm
Now that you mention it  I looked at mine and it seems short in length and then tall. I will leave it alone, I was lucky to just get it posted. lol
 
I went with the Best Gasket rubber seal. I have just installed it, I'm waiting on the arrival of my carb then I'm nervously going to fire it up. Fingers crossed.


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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: smfulle
Date Posted: 03 May 2019 at 8:56pm
Transmission front will drip out that same hole in the bell housing. Tough to tell the difference sometimes.

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Stan
48 CJ2A (Grampa's Jeep)
59 Chevy 1/2 ton
https://www.thecj2apage.com/forums/grampas-cj2a_topic16836.html" rel="nofollow - Grampa's Jeep Build Thread


Posted By: Lhead
Date Posted: 03 May 2019 at 9:56pm
I put a new sealed front bearing in the transmission and plugged the return hole so it shouldn't be coming out of the transmission, at least in theory. I've had the pan off 3 times and finally got it to stop leaking. Looks like it will be coming off again. This engine serial # is 4T31539 so I think that means truck and probably a later model. So from some earlier threads I read on here, it might require the neoprene (or whatever) seal vs the rope seal i have in there. Guess I'll learn more when I pull the pan.



Posted By: cpt logger
Date Posted: 03 May 2019 at 9:58pm
Originally posted by smfulle smfulle wrote:

Transmission front will drip out that same hole in the bell housing. Tough to tell the difference sometimes.


For me the easiest way for me to tell the difference between engine oil & gear lube is by the smell. Gear lube is very potent. If you are unsure what fluid is leaking, get a sample from a piece of cardboard set below the leak. Then compare the smell of the sample to the engine oil on the dipstick. If you are unsure if it is engine oil or not...It is! Gear lube has a very different odor.

Of course it could be both. I know, I know, hush my mouth.


Posted By: Lhead
Date Posted: 03 May 2019 at 10:14pm
Well, it passed the smell test so I guess it's off with the pan. Someone recommended that pulling the engine is the best way to fix the rear seal. That seems like a ton of work to me but I can see their point. I have new both rope and neoprene seals. I guess I'll see which one fits better.


Posted By: 67charger
Date Posted: 03 May 2019 at 10:30pm
Make sure the crank surface the seal rides on is smooth with no pitting or grooves. It will leak if its not smooth


Posted By: willyt
Date Posted: 04 May 2019 at 1:49am
What seal are you using Lhead?

Who are the better manufactures of the neoprene seals?





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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: 67charger
Date Posted: 04 May 2019 at 2:05am
I don't know what my seal is, it's old and not leaking too much "knock on wood".  I just know that the seal surface is as important as the seal.  It's amazing how a rubber lip seal can groove a piece of metal.


Posted By: Bruce W
Date Posted: 04 May 2019 at 5:00am
Originally posted by Lhead Lhead wrote:

I was really careful putting the seals in, leaving a bit exposed to compress.

  The extra you left is now probably between the rear main cap and the block, not allowing the cap to seat correctly, allowing oil to run between the cap and block, and causing uneven wear on the bearing. The rope seal should be cut off flush with the block and the cap.  BW


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It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

We Have Miles to Jeep, Before We Sleep.


Posted By: Lhead
Date Posted: 04 May 2019 at 4:49pm
I'll know more when I pull the pan this afternoon. I just ordered Walck"s USA made seal kit. Not sure who made it. I have both rope and neoprene main seals here but I don't have any of the main cap seals so I ordered the high priced kit. I'll pull the pan and remove the rear main cap so I can see what is going on. First I'll inspect the condition of the crankshaft seal surface. It it's nasty, I'm not sure what I'll do next. Stay tuned and thanks for all the help and suggestions! Larry...


Posted By: Thad
Date Posted: 08 May 2019 at 1:03am
I have installed 3 neoprene seals with no luck. I have pulled the engine and found The clutch needs replacement and that the crank where the seal rides was pitted and could not be turned b/c of small diameter. I've had this area of the crank built up and turned to 2.311 and am ready to install with a rope seal. The cost for this one surface to be made new again was $60, a guide for what to expect. Sure hope it no longer leaks. I sure feel your pain but this might be your best way to proceed.
Thad


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Life is short. Buy a jeep


Posted By: Lhead
Date Posted: 08 May 2019 at 1:55am
Thanks Thad. Tomorrow I'm pulling the pan and rear main cap to see if I can figure out what is going on. I'll post my findings tomorrow. I'm sure hoping I don't have to pull the engine and crank but I guess I'll find out. 

Larry..


Posted By: Bufordjeep
Date Posted: 08 May 2019 at 3:40am
Larry am in the same boat.   Hope to hear good news.
May the flat fender force be with you,



Posted By: Lhead
Date Posted: 08 May 2019 at 6:00am
I've been thinking about the seal issue. Probably overthinking it! But it seems to me that the rubber or neoprene type modern seal would only contact the crankshaft in a very small portion of the surface, e.g. only a few thousands. That small area would be prone to significant wear creating a groove that would make the replacement with similar seals have a difficult time sealing. On the other hand, a rope type seal would spread the seal contact area over a much wider portion of the crankshaft possibly mitigating some crankshaft imperfections. Of course there is no way a rope seal could outperform a well functioning modern neoprene seal in a perfect scenario but maybe it would work better with a less than perfect crankshaft surface area. 

Further to that thinking, while the neoprene seal might have a better seal to the crankshaft, it might not be sealing on its outer perimeter, e.g.against the block and main cap. It seems this might be a critical installation issue considering that the block was originally designed for rope seals. 

I'll know more tomorrow.

Larry...




Posted By: willyt
Date Posted: 08 May 2019 at 1:12pm
Larry if it's not to late, when you install the upper half of the seal, look closely where the lips touch the crank. On my install one end of the seal flattens out and has good contact on the crank, on the other end only the tip of the lip touches the crank. That condition may change when the cap is installed and things are compressed. Just curious to know. Thanks
 


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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: Lhead
Date Posted: 08 May 2019 at 10:50pm
I pulled the pan and rear main cap. Not without incident of course, in prying the pan away from the block it finally gave way and immediately flipped upside down. I had drained the oil but there must have been at least a couple more gallons in the pan. Imagine the mess. The first observation was that one of the two rubber vertical bearing cap seals fell out. Not enough RTV I guess. I was wrong about the type of seal I had even though I'm the one who installed it. You can see in the photo that it is different than the one standing beside it.



Looking up at the crankshaft, the seal surface looks pretty good and you can see the rubber seal still in place. 

At this point, I'm starting to believe the problem might have been the round seals that go between the cap and the block as the main seal looks pretty good. I should have new seals arriving from Walcks today. I'll see what type they are. Any suggestions?

Thanks, Larry...


Posted By: Lhead
Date Posted: 08 May 2019 at 11:11pm
WillyT, to your point, the type of seal installed is almost like a rubber version of the rope seal, e.g. it didn't really have a lip (like the free standing one in the pic), but rather made contact with the crankshaft across a wider area, like 1/4". Another observation, when I took the seal out of the cap, there was a lot of oil around, under, and behind the seal. Makes me thing oil was going around the seal to block/cap area. I didn't use any sealant in there so that may explain the leak.



Posted By: willyt
Date Posted: 09 May 2019 at 1:31pm
I will be starting the engine this evening to see if my reinstall of the seal holds. This will be my third attempt. On install #2 I may have not used enough sealant on the packing rods, the bearing cap dropped as soon as the bolts were loosened. So a bit more sealant used this time.
If this reinstall fails I'm open to another type of seal. Right now I'm not considering a rope seal. If the Best seal is no.1, according to the parts counters people, I wonder who is no.2?


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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: Lhead
Date Posted: 09 May 2019 at 7:06pm
I got the new seal kit from Walcks yesterday and the neoprene seal has a pronounced lip in the front for sealing. However, I can easily slip the new seal into and out of the space between the block and the crank leading me to the conclusion that it would never seal properly. The old one came out pretty easily too. The best measurement I can get without a different set of calipers is about 2.307" which falls into the acceptable range of 3.02-3.12 but that measurement is suspect due to improper tools. The crank is too deep into the block to get a highly accurate measurement with normal calipers. I guess my next move is to try a rope seal.



Posted By: mbullism
Date Posted: 09 May 2019 at 8:12pm
Originally posted by Lhead Lhead wrote:

... is about 2.307" which falls into the acceptable range of 3.02-3.12 ...
.
Ummm...


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Those who do not learn from history are doomed to repeat it... Welcome to 1930's Germany


Posted By: Lhead
Date Posted: 09 May 2019 at 9:26pm
Duh!!! I guess I should read my own posts before posting! My measurement was 3.37 which is obviously bogus too, so I'll give up on the measurement technique since I don't have to proper tool. I'm beginning to agree with whoever said the only good way to fix the rear main seal is to remove the engine. I'm on my last attempt with engine in place. If that doesn't work, then out it comes.



Posted By: Lhead
Date Posted: 11 May 2019 at 4:07pm
It's all back together. I ended up using the rubber seal standing beside the main cap in the first picture. There was no way I was going to get a rope seal up and around the crankshaft without dropping it. The new seal from Walck's slipped in and out too easily so I knew it wouldn't seal. The one I used fit pretty well. I coated it with RTV and got it in place. I've only driven about 4 miles and so far only have very minor drips, about dime size compared to dinner plate size before. The real test will be a longer drive when it stops raining. Thanks for all the help and suggestions.

Larry...


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Larry
46 CJ2A L134
33 Ford Merc Flathead


Posted By: willyt
Date Posted: 11 May 2019 at 5:44pm
Luck to ya. Hope it goes well.

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1952 CJ3A (Lil'Green)
early M38A1(Ole Green)
1970 Jeepster Commando


Posted By: Lhead
Date Posted: 19 May 2019 at 5:12pm
Well, I finally got a decent long ride, about 15 miles. It leaked same as before. Ugh! Nice fresh oil in a big puddle the size of a saucer. Same when I came home. I guess I've reached the point where I pull the engine and crankshaft and start over. I really hate to do that since the engine runs so well. It seems to have plenty of power (relatively speaking) and easily runs at close to 50 mph. 

I guess I'll take the crankshaft to a machine shop to have the rear main seal surface cleaned up while I have it out. Is there any other possible leak points on the real of the block into the bell housing? I just find it hard to believe a main seal can leak that much having just been replaced.

Thanks,

Larry...


Posted By: 67charger
Date Posted: 19 May 2019 at 5:35pm
Your post before the last said you coated the seal with rtv?  Do you mean you coated the actual rubber lip part in rtv silicone?  This could be your problem, the only thing that should be on a seal is oil, vasoline, or bearing grease. 


Posted By: Lhead
Date Posted: 19 May 2019 at 5:51pm
Well, I coated the outside of the seal with RTV, not the inside lip. BUT, like Rick Stivers said somewhere in his video series on rebuilding a T90, "RTV seems to go everywhere but where you want it to go". So there is no guarantee that some didn't find its way onto the lip part of the seal. Especially since you can't see anything once you start to work the seal over the top of the crankshaft. I'm thinking I'll go back with a rope seal but I'll have to see how things look when I blow it all apart. I'm going to live with the puddles for awhile so I can get some driving time in. I wish I could put a diaper on it! Ha Ha!

Larry...


Posted By: Thad
Date Posted: 22 June 2019 at 1:38am
I posted earlier that I had my crank where the rear mail seal rides built up and then turned to 2.311. It is now back in the jeep and no leaks with about an hour on the motor. I did use Walcks neoprene seal. Hope this will be the answer for you.
Thad


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Life is short. Buy a jeep


Posted By: Lhead
Date Posted: 22 June 2019 at 2:09am
Thanks Thad, I'm happy that your fix worked. I'm at the point that I believe I'll have to do something like what you did. What I think I'll do is build up another engine and swap. Then I'll have the leaker fixed for a future project.

Larry...


Posted By: scottpagesr
Date Posted: 07 Aug. 2020 at 3:57pm
Got a CJ3A and had trouble finding info on the rear seal (2 piece neoprene).  Things got confusing because I have not seen manufacturer installation information on any seals and it turns out there are several kinds of seals out there, so it in not just a 2 piece neoprene; it is a specific model/type of neoprene seal.  See my picture below, hopefully you won't have to re-invent the wheel and you will be successful. Please feel free to comment.  I have done some "massaging" on this picture, hopefully to eliminate questions.



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Another Day Closer


Posted By: oldscot3
Date Posted: 09 Aug. 2020 at 1:32am
There is a Youtube channel under the name "Metalshaper" that has vids discussing this issue extensively. Brian says the neoprene Best seals are manufactured to an incorrect spec and won't ever seal properly on a stock Willys crank. He has his cranks welded up on the seal journal and then turned back down to a dimension that works for the neoprene seals, otherwise he uses a rope seal and shows how to install them to best effect. Very interesting vids, should be easy to look up.

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James 4:6 God resists the proud, but gives grace to the humble.


Posted By: misterberry
Date Posted: 09 Aug. 2020 at 10:10am
This is a very interetsting thread. Been debated many places - many posts. 
Ai too had same problems and ended up with neoprene in my rebuilt. I installed an oilpan that was powder coated in an un-educated thinking that i was doing something good.
Opened the sump to correct the oil float hang up condition i developed.
In the sump were remnants of the now peeled interior coating.
To correct my leak - i bought new neoprene ones.
While i thought the oil issue was cured- it never stopped. So- i had it changed
Still had not figured out the idiot owner was issue. After a while -i bought decent new rope scales kits . Buying two , it gave me hope . I did install one set . Only thing i missed was soaking the crap out of thr rope longer than what I did . Needs a LONG time - not an hour or 24. 

Since the time spent on this in the beginning- i have come across an advisory from the american machinists authority which takes recurring problems in machine shops and corrects the issue.
I have a copy some where on a drive that i must locate. 
 Perhaps someone who is a longtime member can check their cranium and add it to this thread . I will still looking. Then it will be good .


-------------
James Berry

'48 2A ser.187593 "Jeep Jeep"

It's a "Lefty"....
Moved north from California-
Now waving the Canadian flag -
A Canuck back home in Edmonton



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