tranny leak problem

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Sep 30, 2012 | 08:05 PM

#11

Potato_Potato

Outstanding HDF Member

Joined: Sep 2005

Posts: 2,600

Likes: 7

From: Minnesota

Quote:

Originally Posted by Born2cure

I put in 75/90 gear oil in tranny, think I messed up. I have an oil leak just the tranny for now. seems like it is comeing from the pan. I changed the o-ring just hoping but still bad. would a bad oil pan gasket cause the tranny to leak. should i drop the pan and change the gasket. or could there be another cause. wondering if the 70/90 could have caused to much pressure and blew out a seal or gasket. or crap i doun't know.
thanks guys

75w-90 is not an overly viscous gear oil for your tranny and is approximately equal to 20w-50 motor oil, as gear and motor oils are measured on different scales. But in any event I don’t see how any weight oil could blow seals or gaskets because the tranny is vented.

If the leak started after changing your tranny oil could it be that you overfilled it and it is coming out of the vent on top of the tranny and leaking down giving the appearance of leaking from the pan area?

I’d bet a silver dollar (if I had one) that it is leaking through the vent or as flhrbill said, the bottom 2 bolts of the tranny side door that also fasten the exhaust bracket.

Last edited by Potato_Potato; Sep 30, 2012 at 08:08 PM.

Oct 1, 2012 | 06:08 PM

#12

WAYJO

Cruiser

Joined: Apr 2012

Posts: 143

Likes: 20

From: Tonawanda, N.Y.

Did you replace the o-ring on the drain plug when you put it back in? Or at least take a good look at the old one before re-using it?

Oct 1, 2012 | 07:05 PM

#13

Scorpion07

Road Warrior

Joined: Jun 2008

Posts: 1,602

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From: Southeastern Michigan

Sounds like it could be the main drive gear seal. Problem is its usually a bad main drive gear bearing that causes it. You'd have to tear down the trans to change it. Big job.
Could be coincidental that it let go at the same time you changed the oil.
I've never heard of the pan gasket going.

Oct 2, 2012 | 08:07 AM

#14

Born2cure

Thread Starter

Road Captain

Joined: Oct 2007

Posts: 743

Likes: 0

From: Morris, Il

Thanks guys going out to spray down with breakkleen and see where it's at. Seems to be from top of pan so hoping its coming from the vent (wasn't aware of the vent) I did change the o-ring. It's shifting good will check levels and go from there. Will post when I find the cause.
Thanks again HDForums always come through

Oct 2, 2012 | 11:30 AM

#15

TUCCI

Extreme HDF Member

Joined: Jun 2011

Posts: 10,216

Likes: 224

From: Glendale AZ

Have you checked the header bracket bolts that attach to the bottom of the chrome cover. When I had my cover off to install a longer cable I removed the bolts and gooped them with locktite. Its worthwhile to take the header away from the mount and do likewise.