Jump to content

Chasing Tranny leaks


drtidmore

Recommended Posts

I am about to replace the bottom tranny gasket (and filter) with a FelPro gasket and am curious if it is even possible to replace the side pan gasket short of pulling the transmission?  The leak I am having is clearly around the drivers side in the area where the side and bottom pan meet.  I discovered that the bolts on the side pan were a tad looser than I expected so I snugged them up for the time being, but as the side pan gasket is original, it is likely brittle and could well be the source of my leak.  Any thoughts on its potential replacement difficulty.  I have not yet looked in the FSM as I know that it tends to take the yank and replace strategy rather than what is possible short of yanking the tranny out. 

 

Thoughts appreciated.

Link to comment
Share on other sites

A complete rebuild is possible "in frame". It's a matter of taking the cradle apart, removing the axle, knuckle-strut combo, stabilizer link, dogbone, shift connections, etc. then lowering the entire powertrain down at an angle. The side pan can then be removed, then a new gasket and axle seal installed. You don't have to remove any internal transmission components for simple side pan removal.

 

The most difficult bolt to remove will be the one Subframe bolt just under the AC compressor. Slightly lifting the engine will allow access to it. Penetrating oil everything first. I only use 50-50 acetone-ATF in a pump oil can.

 

A short video- describing this procedure is on my channel. The original video job is an in depth 3-part series; I took a part of part 1 and edited it for content. I completely removed my unit- but I also had many more issues to tackle.

 

VIDEO

Edited by 89RedDarkGrey (see edit history)
  • Like 1
Link to comment
Share on other sites

89RDG, 

Thanks for the video.  I am going to watch to see if tightening the bolts seems to have made any difference and of course I intend to drop the bottom pan and replace the filter and gasket as well before deciding to do the side pan gasket.  At least I can see that it is possible to do in-frame.  

  • Like 1
Link to comment
Share on other sites

My best luck with filters has been Pro-King. Rubber is superior to paper or cork. OEM side cover is usually cork- worse than useless, especially if leaking; tightening will probably make it crack and leak worse. I also don't recommend adding any "stop leak" to a transmission.

Edited by 89RedDarkGrey
brandname (see edit history)
Link to comment
Share on other sites

For the filter seal- use a flat blade screwdriver and small hammer. Hold the blade perpendicular to the seal lip, tap sharply to cave it in, pull it out. DO NOT pry against the aluminum body. Use Vaseline to lube the seal before filter insertion. I always use 3M spray adhesive on the pan side of the gasket to ensure seal, never RTV. Make sure the washers are freely moving, to ensure even torque.

 

DCP_5537.thumb.JPG.d1822a9a2f21af7c35c070462b4fc5a0.JPG DCP_5546.thumb.JPG.0a9359ec8c49ecf5a9868b07a0d0ca45.JPG DCP_5547.thumb.JPG.0aa30524feaf84f9d184a88693b6b6ad.JPG DCP_5548.thumb.JPG.332e59982eb97a090f2dc6fd8f57843c.JPG

 

 

 

 

Link to comment
Share on other sites

28 minutes ago, 89RedDarkGrey said:

My best luck with filters has been Trans-King. Rubber is superior to paper or cork. OEM side cover is usually cork- worse than useless, especially if leaking; tightening will probably make it crack and leak worse.

In looking at the side seal that is protruding at the edge, it appears to be a cork/composite material rather than solid cork.  The lower bolts that I snugged up were actually pretty loose as I was able to move then using a short box end with just pressure from my fingertips.  I just snugged them up as I know better than to tighten gaskets too much, especially old ones.  I agree on the use of rubber gaskets such as the FelPro line.  I will look into the Trans-King line of filters.  Thanks for the tip.

Link to comment
Share on other sites

  • 2 weeks later...

Just a followup on the tranny leaks.  I chose to install an AC Delco Pro filter and gasket set.  Using my handy oil extraction pump, I pumped as much of the old tranny fluid as possible and then I removed the pan.  As I loosed the pan bolts such that the back side would drop down first, I found still more fluid, but not as much as when I have done this job without pulling fluid using the pump.  There were no shavings on the magnet and no unexpected pieces laying in the pan (thank goodness).  I cleaned up the pan, replaced the front accumulator hose located just above the filter and then installed the new filter and gasket on the pan and reinstalled the pan.  Added in 5 quarts of Dextron VI initially but then added in an additional 2 quarts (7 total) to get the fluid level to the full mark once the tranny was at operating temps.  The good news is my leak issue has vanished, so despite my fears that it might be the side pan, the leak was around the bottom pan. Shifts, up and down, are positive and smooth. 

Edited by drtidmore (see edit history)
  • Like 1
Link to comment
Share on other sites

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 account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...