4.0L rear main cap "sealant"? - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 03-30-2001, 03:53 PM Thread Starter
Journeyman
 
gmoabrim's Avatar
 
Join Date: Mar 2000
Location: Moab, Utah
Posts: 199
Thanks: 0
Thanked 0 Times in 0 Posts
 
4.0L rear main cap \"sealant\"?

I'm replacing the rear main seal in a 1990 4.0L engine (in my 83 CJ-7). My 94 ZJ manual says to use a thin bead of Loctite 515 on the main cap to block mating surface which neither of the two parts stores in town have ever heard of. My 83 CJ manual (258 engine) says to use a small amount of silicone on the edge of the cap. Is the 515 an anerobic sealant or a silicone sealant and is it really necessary?

Thanks in advance,

GaryM

gmoabrim is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 03-30-2001, 10:25 PM
 
Join Date: Sep 1999
Posts: 2,137
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: 4.0L rear main cap \"sealant\"?

Gary-
The whole idea is to prevent oil from the crankcase from migrating across the 'seat' of the rear main and it's cap.
The rear main seal is for the crank but the 'very' thin bead along the back edge of the almost completely flush surface areas were the cap meets the block is what they are talking about.
If you gob on too much on the seat you will alter the cap's ID and cause too much clearance for that rear main bearing.
Just put a little dab of silicone or locktite on you finger and wipe it across the rear edge of the cap's (very clean ... use alcohol) seat ... no more than 1/16" wide.
That should 'smoosh' out and seal the seam without altering the cap to crank clearance...

P.S.
I got a lot of tips on 258 pan gaskets and chose this very sucessful method ...
Use 3M Weather Seal (AKA: Gorilla Snot) on the rubber end gaskets and brush on Permatex Aviation gasket goop on the block's pan seat area and let it dry a little ... then place the cork on the sides.
Next put a 360* bead of the 3M 'snot' ... paying particular care to gob at the gasket junctions.
Set the pan on and use only a nut driver (the handle style), carefully settle the pan down.
Then, carefully snug down the bolts from the middle of the block to the seams en a very even fashion...
The trick is to squish the side cork a little without causing it to move out of positon... it doesn't take much pressure ...
Then, after a hundred miles or so, had tighten the bolts again ... once more being careful not to over do it ... you shouldn't have any leaks.

The trick in this is that the Aviation Permatex is thin but tacky - to keep the gasket in place and perfect for the smooth seat on the block and the cork.
The pan's seat is very irregular and hence, use the rubbery, oil impervious 'snot' for this seal.
Hey, It worked for me ... and others - or I wouldn't be passing this tip along ...

Good luck ... mine has well over 500 miles so far on my home rebuild and I've not seen even one tiny drop or smudge of oil yet ... better 'n factory ...


JAF
http://www.monsterslayer.com/jeep
Jaffer is offline  
post #3 of (permalink) Old 03-31-2001, 04:34 AM Thread Starter
Journeyman
 
gmoabrim's Avatar
 
Join Date: Mar 2000
Location: Moab, Utah
Posts: 199
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: 4.0L rear main cap \"sealant\"?

Thanks Jaffer, I bought the g.snot to secure the gasket to the block since I'm in an upside-down position and will use some silicone on the flat surfaces as suggested. It always worked on the ole' 258 and the 4.0 looks the same (from the bottom up anyways).
GM

gmoabrim is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome