Dropping Crank For Rear Main Seal

Ok... this feels like an amateur question, but I have to ask it:

I bought new neoprene seals for my 61 CJ5 after dealing with a continuous leak after driving. I took the oil pan off and the rear main cap and removed the original seals, which were neoprene to my surprise, so someone else has been in there I assume.

No I am going in and trying to put in the top seal with crank in place, i can barely even get it started. I loosen all the mains and the crankshaft barely budged. I loosen all the rod caps too to see if those are holding them up. Nothing there either.

All I can assume is that the flywheel and clutch is holding the crank in place? I assume I am going to need to take the transmission off to drop the crank to get that top seal in?

Any pointers, I thought I could do this with crank in place like my old 4.0L I6 Jeep TJ, but apparently not. Seal was from KaiserWillys, I assumed it would be good quality .

 

Push in the clutch?

 

Try having someone turn the crank as you push in to help “pull” the seal around. Oil the end of the seal as well before inserting.

 

Iharding, I actually tried this with no effect. Then it occured to me that the trans input shaft is in the pilot bearing so it probably wouldnt move anyway right?

65cj5, working on getting some help to try this out too. Was attempting to do it one handed, but that was a failed attempt

Thanks for the help so far guys, I appreciate it!

 

Ah. True. I tried this job but couldn’t even get the main cap bolts loose and gave up so don’t listen to me!

 

I definitely benefitted from a second set of hands! My seal was also front/back specific so I took special care to make sure I was sliding it in correctly. All I had to remove was the rear main cap. It was an awesome feeling seeing it slide up in place. Good luck!

 

Wow didn't think of that, I put mine in on an engine stand it was easy, pulled the crank pully, and loosened the mains, piece of cake.

 

65Cj5, where did you get your seals from? I am starting to wonder if my KaiserWillys seals are too large. Very difficult to even get one started in the groove. I am certain I am putting it in correctly, it's just very tight in there.

 

Put that seal in the freezer overnight, it will shrink a tad.

 

Hmmm good idea, I will give the freezer it a try! Thanks

 

I used this one from eBay and I have had very good luck. I’ve had this seal in place for almost a year and haven’t had one drip. I am very happy with mine. The seller says they are one of the best on the market and I believe him.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/112320472680

 

This is the second time i have been referenced to this seal on ebay. Went ahead and ordered on based on your experience. Worth it to me fo try it out. Thanks!

 

When you install the upper side of the seal, position it on the underside of the crank, and push the old top half out as the new one guides in. Leave about 1/4" offset at the block/main cap line.
I've bought the seal on eBay from QTM/quarterton military and it was real nice quality-no leaks!
-Donny

 

That looks like the one I used. I got it from Midwest Military. They also tell you not to "clock" the ends. Just leave them up equally on each side.
I turned the crank while a friend fed the seal in. He got a lot of oil on him and was unhappy.

 

Good to hear the success stories, my new seal will be here Friday, so I will be eager to try and get it in. Hopefully I just needed this better seal.

 

….and a friend to feed it in while you turn the crank...

 

That too! I have a buddy lined up to help

 

Not sure what it is meant by don't "clock" the ends.

 

Got this picture from another thread (thanks Johns1967CJ5)
The top half and the bottom half are turned 3/8-1/2” so they don’t line up straight across. That way the seam where they meet isn’t straight across. Hope this makes sense. BTW, I did not do this, my instructions said not to.

 

Thanks. I have seen this and it makes sense to me. I did not do it AND it leaks. Next time I'll do it this way.