lets talk pan gaskets and rear main seals

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dusterbd13

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never had good luck with oil pan gaskets, and this continues to be true.
im pulling the engine from my duster in a few weeks to change it, as well as do my tremec conversion, cleaning, etc.

anyway, im running an LA style 360, with a kevco 7 quart pan. what is the BEST gasket on the market for these? with the small block chevy, fel\pro makes a one piece silicne gasket with a steel core and crush sleeves that comes complete with alignment pins and new bolts. is one availible for the mopar?

really, there HAS to be a better option than the 4 peice cork/rubber piece of crap ive been stuck with for the last decade or two....

also, rear main seals: dont know if mine is leaking or not, but if it is, again, whats the best option here?
 
I have had no problems with the cork style gaskets, CLEAN is the key... I have a pan on my daily driver I installed 6 years ago, still dry as a bone!
 
fishy68 said:
JEGS and Summit both show steel core rubber gaskets for LA's. Here are the links

http://www.jegs.com/i/Fel+Pro/375/1807/10002/-1

The one odd thing is that it's still a 4 piece gasket, but at least it's steel core nitrile rubber. Price is real good too.

http://www.summitracing.com/parts/mil-41007/overview/make/dodge

More costly but it's a 1 piece gasket. I think if I were in the market it's the one I'd buy.
Click to expand...

I'm in the market for an oil pan gasket for my 360/408 as well...That one piece rubber unit looks like the key...maybe I will give that a try??

wonder if ya gotta use some RTV with it? or at least a dab in each corner?
 
I've never had much problem, the usual Fel Pro or Victor gaskets. I do NOT use the end seals either in the pan or intake.

CLEAN

Get the pan rails STRAIGHT, tap out any holes that have been dimpled form overtightening.

CLEAN

I can't remember "Hi tach?" Permatex is what I use, it s the dark read "soupy" stuff, glue the gaskets to the block, assuming it's inverted on the stand. Take the time to get them well aligned, use a few bolts, etc

When they are "tacked" in place, apply the last coats to the pan and gasket, then lay a huge bead of RTV front/ rear, and set the pan in place. DO NOT overtighten. If you're a big guy, use a 1/4" drive set. Or hold your 3/8 drive up around the head, and tighten criss--cross front to rear a little at a time.

As soon as you get it "seated" take your finger or towel, and smooth the bead into the gap, take care to make sure it's completely filled

Then a final tightening if necessary, and do not fill or start for 48 hrs if you can afford it
 
mopardude318 said:
whoops. NEVERMIND....read this thread. do not use that one piece rubber seal. its for a magnum motor only. use the MILODON crushproof oil pan gasket.

http://www.forabodiesonly.com/mopar/showthread.php?t=203796&highlight=oil+pan+gasket

http://www.summitracing.com/parts/mil-40650
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Yeah I remember that thread now. I did state that the magnum gasket doesn't fit right but the OP said he used a Fel-pro gasket which shows to be a magnum gasket. AutoX also said the magnum gasket didn't fit right but I didn't see where the Milodon was specifically mentioned, just Fel-pro and Detroit gasket.

I just did a search to see if I could verify what it's really for (LA or Magnum) and this is the only one I came up with that says it fits an LA but at the same time a couple of guys say the magnum gasket works fine on an LA, which I know is wrong cause me and AutoX have tried it. I guess take this thread with a grain of salt

http://board.moparts.org/ubbthreads...age=1&Main=5858423&Words=&topic=1&Search=true

Out of 3400 hits on Google I found no definete proof that the Milodon actually fits. Even Milodon's website just says it's for a 360 Mopar, doesn't say LA or Magnum.

With that said buy at your own risk. At least Summit is good about taking back stuff if it doesn't fit. Use their return label and it won't cost anything except time so if you order it way in advance you'll be ok.
 
as stated, cleanliness and straight faces are a huge deal, if black rtv doesnt suit you fancy, and if you dont feel like using a chisel next time, stay away from "right-stuff", or if you dont have to fill a huge gap, ive had awesome results with aviation form-a-gasket, or indian head shellac, same stuff essentially. Gooey, sticky, stinky, awesome stuff! just keep a bottle of iso-heet nearby so if you get some in a place you dont want it, you can clean it up easily. It works great for using as a high-tack product, and it is resistant to pretty much any automotive fluid known to man.
 
I did this on my latest 340 build. Cut the Magnum pan rails from a late model one piece Magnum gasket (rubbber with steel insert). Used the stock 340 rubber pan gasket ends. RTV'd the corners. This was a recommendation from Brian Halflinger at IMM engines. The steel core prevents the over tightening of a cork or solid rubber and distorting it. :glasses7:
 
You can get a standard Fel-pro gasket to seal, but here is what you have to do.
Make sure the flanges are straight.
Use a light coating of permetex on the cork, and end seals. Use rubber gloves and make sure every surface is covered.
Before putting the pan on make a 1/4" bead of the corners.
Do not use the factory torque settings, they will distort the gasket, just run them down to about 1/2 the recommended torque.
Let sit 48 hrs before placing in service.
You will not have a leak.
 
There a few local people I've seen in person have problems with aftermarket cranks and rubber/viton/whatever rear main seals. I have one in my 416 with Scat crank and it seaps.

I know of two people that have cured this problem with old fashioned rope seals. Sure they put more drag on the crank and "might" cost you a couple of HP. But I will trade a couple HP for a dry rear seal.

I'm putting in a rope seal next time aftermarket crank or not. I'm not going to take the chance.
 
I had to use a rear main "rope" seal in my 1948 flat head willys, it took up the "out of round rough seal surface" in a 60 year old part.
 
ill switch to a rope seal.

and the milodon works with the LA pan, right?


by the way, NOT looking forward to this job. not at all.....


if i could figure a way to do it in the car and be successful, i would. but never had any luck doing it in the car in an a-body.

michael
 
dusterbd13 said:
if i could figure a way to do it in the car and be successful, i would. but never had any luck doing it in the car in an a-body.

michael
Click to expand...

Gonna watch this thread to see if anyone chimes in on the rear main topic.

I also was wondering if the rear main can be replaced in my 340 without pulling the motor. I get oil drips from the back of my pan after driving hard/winding up the motor...gonna replace the gasket (again)...but fear it's the rear main. :banghead:

Pat
 
Have you guys with leaky rear main seals tried staggering the seal and using a very small amount of RTV on the ends where it butts together? I started doing that a few yrs. ago and haven't had one leak since.
 
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