Author Topic: Gear box leaking 85 K20  (Read 1005 times)

Offline silverchev08@gmail.com

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  • GMC K20
Gear box leaking 85 K20
« on: February 23, 2019, 08:23:43 AM »
85 GMC K20
Spots of trans fluid on driveway. Had the rear seal of transmission replaced where drive shaft attaches due to minor leak. Well come to find out the leak seems to be coming from the top of the gear box. Truck runs and Shifts ok. Is the leak as simple as pulling the great box and replacing gasket? Something I can do our should I have this done?

Also have minor oil leak from what I think is the rear main seal. Probably getting this fixed soon along with oil pan gasket.

What is the expertise or technical factor/degree with doing this myself or is it better to have a professional mechanic do the work?

Offline JohnnyPopper

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  • Posts: 2548
  • Old Goof
Re: Gear box leaking 85 K20
« Reply #1 on: February 25, 2019, 12:44:09 PM »
Welcome from SoCal.

From what I can tell, you seem to have a manual transmission, right?

I would start there, by saying just what you have.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction