Engine gasket set

Discussion topics on Willys Overland M series vehicles
Post Reply
User avatar
wilfreeman
Jeep Legend
Jeep Legend
Posts: 1079
Joined: Sun Mar 12, 2006 6:00 pm
Location: Richburg, SC
Contact:

Engine gasket set

Post by wilfreeman »

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.
Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
User avatar
wesk
Site Administrator
Site Administrator
Posts: 16464
Joined: Sun Apr 03, 2005 6:00 pm
Location: Wisconsin
Contact:

Post by wesk »

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.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
User avatar
mrm38a1
Member
Posts: 4
Joined: Sun Feb 09, 2014 6:00 pm
Location: DUNEDIN FL

REAR MAIN SEAL

Post by mrm38a1 »

I USE REAR MAINS FROM JOHN AT MIDWEST MILITARY,WORK WELL ON MY 53 M38A1.
User avatar
wilfreeman
Jeep Legend
Jeep Legend
Posts: 1079
Joined: Sun Mar 12, 2006 6:00 pm
Location: Richburg, SC
Contact:

Post by wilfreeman »

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!
Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
User avatar
G740
Jeep Enthusiast
Jeep Enthusiast
Posts: 500
Joined: Thu Jan 26, 2006 6:00 pm

Gasket kit

Post by G740 »

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
Post Reply