Rear main seal

[Charlie]

I have a very minor leak at rear main seal, maybe a teaspoon every week or so. Should I just drive it and top off every few weeks or maybe have it done and do a rebuild since engine will be out anway. I only show 107,000 miles and it runs great. Opinions from everyone are requested, Thank you in advance

Charlie of the purist camp

[ImEvil1]

Charlie,

Not sure if I read your question correctly....are you planning on pulling the engine for a rebuild?

I've had rear main leaks on 2 of my cars....one was just seeping (like yours) and the other was much worse (on a 15K mile car). I had them both fixed at Ford, under warranty. They have both been fine since.

[Charlie]

Sorry Mike, Im just trying to find out if this small leak is ok to leave or if it is an immediate fix required. If I must fix than I wanted to see if doing a rebuild when the engine is out anyway is best. Thanks Charlie

[NoDrama43]

Charlie,

I would not pull the engine just to replace the rear main seal if it is only leaking that much. If the leak bothers you to the point you want to fix it you have several choices.

1. Drop the trans and just replace the rear main (simple fix).

2. Jerk the motor and trans, do a complete rebuild/overhaul fixing the seal then.

3. Jerk the motor and trans, detail the engine compartment and engine , replacing the rear main at that time. I would also do the timing chain, oil pan gasket, valve cover and intake gaskets while I was at it.

If the motor only has 107k and still holds good oil pressure, with no smoke, or rattles, etc. I would opt for number one. It just depends on your long term plans. If you had already planned to jerk the motor to detail the engine compartment, K member etc, then the only decision is when you want to jump in and get it done. If you have a drill and a small slide hammer swapping out the rear main is an easy job. These motors are hard as nails and based on my experience,if treated right, you can go upwards towards 200k before needing the serious stuff.

[ssp91ssp]

Charlie,
If you go with the drop the trans option , Felpro sells a crank repair sleeve just in case there are any imperfections to the seal surface area on the crank.
I have used several along with the Felpro marine rear main seal, leak gone !!
hope this helps some .

Hector

[NoDrama43]

+ 100 for using the Marine grade seal !!

[Charlie]

Thanks all: I will be better prepared to deal with my next project now. This car will never die. I will see to it

Charlie of the purist camp

[ajstoys63]

I just had mine done and it is dry now... I was leaking quite abit. I had a trans shop do it and they serviced the trans and replaced the trans valve body as well as a trans service for $900. They also installed my new H-pipe as well....

[SSPaul]

Just be sure that the leak is from the rear main before pulling the the trans. These engines are notorious for lower intake gaskets leaking oil. Try and look down the back of the engine with a flashlight and mirror and look to see if there is any signs of leakage from the lower. If you pull the intake don't forget to replace the valve Cover gaskets,pcv valve and the metal pcv valve filter below the valve.

[Cobra Jet]

Charlie,
... Felpro marine rear main seal... Hector

Does anyone have the part # for the Felpro "Marine" RMS? I know Felpro has the standard RMS (rubber) and the Teflon RMS - never heard of this "Marine" RMS....

If wanting to purchase one, where to buy and what is the cost compared to the standard or telfon?

[ajstoys63]

Question... Where do you find these marine grade rear main seals?? My Mustang is good now but my LTD LX is having an issue...My friend said he would help me yank the transmission to replace it but I refuse to put another Ford seal in it considering it would be the third one... Yes I do hav the Felpro crank sleave on it. The Ford seals just crumble. The LTD's front seal just fell apart. I just replaced that when I replaced the cam....