robfg67 Posted January 16, 2008 Posted January 16, 2008 After degreasing the lower half of engine & transmission (to locate the source of the leak) I was able to identify the main rear seal as the source of an intermittent oil leak from my 1989 Comanche (with the I6 engine). I know the correct way of replacing the seal is to first remove the starter, transmission, and possibly oil pan to access the seal. I have never done this before and it is probably above my automotive skill level. Could I try Marvel Mystery Oil? Has anyone used this before? A mechanic friend of mine said it can be used to seal leaks, but he has seen it also seal the heater core in some vehicles. A half a bottle of Marvel Mystery Oil sounds like a reasonable attempt. What do you guys think? Here is a picture of my baby:
BLHTAZ Posted January 16, 2008 Posted January 16, 2008 The Marvel trick is typically to cause "gaskets" to swell a little and stop them from leaking. You could try it if you want as it would not hurt anything, but that seal is rubber and when it starts leaking...it just keeps getting worse. You do not have to remove the tranny to do that job...just the oil pan so you will need a pan gasket and a seal. If you are doing it yourself for the first time you will need to be VERY aware of how the seal is oriented. If yuo put it in wrong, your leak will be worse than before.
Geonovast Posted January 16, 2008 Posted January 16, 2008 I've never heard of it. I usually don't bother trusting stuff like that though. You do not have to remove the transmission in order to replace the seal. Drop the pan, then pop off the rear crank bearing thingermabobber. (I can't recal what it's actually called atm.) DO NOT SCRATCH THE BEARING. That's what my brother did and effectively put a stop to my J10 existing. The rear main is a 2 piece seal, one stuck in the block and one in the thingermabobber. Having the tranny out would make it a great deal eaiser, but you don't have to. Have fun getting the pan out from under the truck.
robfg67 Posted January 16, 2008 Author Posted January 16, 2008 Thanks Brent, I can handle oil pan removal-it was the transmission that had me worried. I understand that the MMO can swell some types of gaskets. I wasn't sure if it could do anything with a rubber seal.
robfg67 Posted January 16, 2008 Author Posted January 16, 2008 I guess my next purchase will be a repair manual!
robfg67 Posted January 16, 2008 Author Posted January 16, 2008 Yes I do. I'll assume that using a torque wrench on this project is important.
FxRacing282 Posted January 16, 2008 Posted January 16, 2008 dude... use the mystery oil in your oil. the stuff has worked wondors for me and others.... then if it dosent stop it id worryt about replacing the seal. why spend the money and time to change something when all you may have to do is spend $4.99 and 2 minutes putting it in?
Tonedef131 Posted January 16, 2008 Posted January 16, 2008 why spend the money and time to change something when all you may have to do is spend $4.99 and 2 minutes putting it in?Because even if it works it is a temporary fix and if he is planning to keep the truck long term he is going to need to replace it eventually.
FxRacing282 Posted January 16, 2008 Posted January 16, 2008 yeah but why bust your balls in the winter? you can do it in the spring when its nice out and the driveway/concrete isnt wet/cold
Tonedef131 Posted January 16, 2008 Posted January 16, 2008 yeah but why bust your balls in the winter? you can do it in the spring when its nice out and the driveway/concrete isnt wet/coldI actually get a lot more of my automotive work done during the winter. I can pull the truck in the garage and get it done when it is too nasty out to do anything outside. During the summer I would rather be doing outside activites than be stuck under a truck covered in oil.
BLHTAZ Posted January 16, 2008 Posted January 16, 2008 Yep...that's why I said give it a shot first...it can't hurt and if it works for a while to get you through, that's all the better ;) .
robfg67 Posted January 16, 2008 Author Posted January 16, 2008 I will definitely get the seal changed at some point-I just wanted to know if anyone had any experiences, good or bad with MMO. If it doesn't cause any harm and can possibly fix it, if only temporarily, that will be good enough for now.
robfg67 Posted January 18, 2008 Author Posted January 18, 2008 I drained about a quart of oil from the pan & addded about 20 ounces of MMO on Wednesday night (1/16/08). I'll update this post with any changes.
FxRacing282 Posted January 18, 2008 Posted January 18, 2008 hmmm i woiuld have just poured it in there :wrench:
robfg67 Posted January 18, 2008 Author Posted January 18, 2008 I didn't want to overfill. The directions on the MMO bottle recommend that you substitute a quart of MMO for a quart of oil at next oil change.
lawmanbsi Posted January 18, 2008 Posted January 18, 2008 machanic at work put some in my work van and for about two months it stopped the blow by. I didn't have any oil leaking so I don't knew if it would work or, how long .
FxRacing282 Posted January 19, 2008 Posted January 19, 2008 I didn't want to overfill. The directions on the MMO bottle recommend that you substitute a quart of MMO for a quart of oil at next oil change. you read the directions?? :nuts:
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now