willysmjeeps.com

Hey guys,

I am almost finished collecting parts for my long needed engine rebuild. I was looking at the Fel-pro full gasket sets. Under additional details, it mentions that the rear main seal is NOT included. Further reading reveals a note that says Rear main bearing seal for MILITARY engine is NOT included. Why would there be a difference in the rear seal between military and civilian engines? What are my choices with that? Can anyone recommend a good gasket set that DOESN'T cost $95. I saw the Omix Ada ones, but would rather not go that route.

Edit: after posting, I looked up the rear seal separately. They have a rope seal set for $21 MORE. BUT it also says NOT for military engine.

The statement on the catalog is misleading. There are no differences between military engine and Civvy engine rear seals. Both the military engine and the civvy engines started out with the rope seal and later production changes in the crank machining led to the preformed seal.

You can pre-buy a lot of stuff for an engine overhaul but do not buy anything that may have more than one choice is shape or size until you disassemble the engine and know for sure what you have.

My photo album is the second album. Go there and review the sub album on the rear oil seals. When the time comes to pick a seal first see what type machining is on your cranks rear seal surface. If it is machined properly for the pre-formed seal then you can use either preformed or rope. If it is not machined properly for a preformed seal you can only use the rope seal. Be sure you check dimensions and condition of the sealing surfaces closely.

Also beware any NOS surplussed preformed seals produced in the late 80's thru the end of the 90's.

I USE REAR MAINS FROM JOHN AT MIDWEST MILITARY,WORK WELL ON MY 53 M38A1.

It didn't make sense that there was a difference and had never heard that in the 20yrs I've owned/been working on these engines. Just wanted to make sure because I don't want to do it again any time soon. This engine was SUPPOSEDLY rebuilt before I bought the Jeep 20yrs ago, then I let it sit up for 10 yrs, during which a piston seized in the bore, a valve stuck and the exhaust valve guides cracked and broke apart. I have located and purchased new exhaust valves from Italy (cheaper to buy and ship 4 NOS Willys ones than 1 from the US!, so I might as well replace them all - these are the tapered, Rotoloc? ones).

So far, I have only bought the valves, valve guides and camshaft (bad fuel pump lobe). I rebuilt the distributor and carb, and had the starter, generator and head rebuilt. I know I can go ahead and buy the gasket set, but will have to wait for the machine shop to do their thing before I buy bearings and rings/pistons.

I'll have to check your album out about the crank and seals tonight Wes. I have a rear seal leak on the engine that is installed now (along with a front seal, transfer case pinion and a rear diff pinion leak). I am planning on running this engine/tranny/transfer case in on a stand and fixing anything that leaks before installing - again, I don't want to be doing this again anytime soon!

MWM also uses copper head gaskets. These are far superior to the felpro or other commercially available head gaskets. The new head gasket material used by them has issues, and not good ones.
John