Leaking Transmission

[MikeyB]

I have an '01 2500 HD and the trans has now started leaking. It appears to be seeping out a seal at the gear selector shaft that goes into the transmission on the left rear of the fluid pan. Anyone else experience this and if so what was the fix?

Thanks,
Mike

[DmaxMaverick]

This is not common by any means, but it's a seal, and they can leak.

If you don't have a subscription at www.alldatadiy.com (http://www.alldatadiy.com), get one. It details the seal replacement. It isn't difficult, but there is a process, and several caveats and tips to prevent damage and ensure proper operation. Too much to go into in a thread without posting the entire procedure page and diagrams (it's copyrighted). Major skill isn't required, and it can be done in your driveway.

[MikeyB]

Dmax,

Thanks for the info. I did sign up for Alldata but it doesn't have part numbers and isn't specific if I can just replace the seal or if I must replace the entire Park/Neutral Position Switch. Any advice?

Thanks,
Mike

[DmaxMaverick]

The part number (and/or the part) can be had at the GM dealer, or an Allison distributor (way cheaper, and you'll get the right part the first time).

You don't have to replace the switch, shaft or detent lever. Removal and reinstallation, however, is necessary to replace the seal. The switch only needs to be moved out of the way so you can access the shaft. If you have trouble locating the correct page in alldata, let me know and I'll tell you how to find it. Alldata lists many part numbers, but rarely for the smaller stuff, like single seals. It is probably part of a seal kit, but should be available from Allison as a single part, which GM may not be able to get separately. Read the procedure carefully and have the parts and tools on hand. Shouldn't be too difficult.

[MikeyB]

Dmax,

I would appreciate that. Alldata doesn't seem too user friendly to someone like me. All I can find is Park/Neutral Position Switch Replacement. Nothing regarding just changing the seal or a parts diagram with numbers and breakdown, etc.

Thanks,
Mike

[DmaxMaverick]

Alldata takes some getting used to, but once you can find you way around, it's pretty easy.


-Transmission and Drivetrain
--Automatic Transmission/Transaxle
---Shift Linkage
----Selector Shaft
-----Service and Repair
------Selector Shaft and Detent Lever Replacement