Got a 1990 C-4 with the L-98 engine and automatic transmission. There is one small leak coming from the front of the transmission, took it to the Stealer, err I mean the dealer, to get it checked out. it is small but since it is transmission fluid it spreads out on the floor and looks worse than it is. The dealer mechanic put it on the rack and pulled the inspection cover. he showed me the leak, it is near the pump and will require taking the tranny completely out, removing the pump, putting in a new seal and then putting it all back together. Estimate of nearly $800 for the repair.

The mechanic checked my mileage and said the problem is so small that he does not recommend spending that money right now. he estimates I will lose approximately 1 pint every 3 months or so. I brought it home based on his recommendation, but would like to hear from you guys if you think that is a sound decision. I have no problem checking my levels and adding as needed but I am slightly worried I may cause larger or different problem by not fixing it now. Suggestions and advice are welcome.....

P.S. The rest of the car is dry as a powder keg with no leaks anywhere....

 

i would go somewhere other than the dealership. you know the problem and should be very simple for any trans shop. the deal is that its a leak. i wont seal itself only get bigger. if you let the fluid go down then you risk damage thats gona cost more than the initial investment. also if the trans is all stock then you could also have them install a shift kit for little to nothing extra and you wouldnt be disappointed. how many miles are on the trans anyhow? is it time for a service? there would be more than one benifit to getting this fixed. how mechanical are you? not sure how hard it is to remove a trans on one of these but i have pulled several and as long as you have a second set of hands its pretty easy.

 

The transmission was just serviced last month, it already has a shift kit installed, not much extra to do to it. I am NOT a mechanically inclined person and usually have to pay for anything other than standard service work. I am definately not comfortable enough to do this myself, but have thought about calling a few of my friends that are more accomplished and having a transmission party.....

 

I think the "stealer" was right on the money,maybe even a little low. R&Ring the tranny in a C4 takes a lot of time and more tools than the average home handyman has in his garage and there are a few things that could bite you. The exhaust will have to come down with the ever present danger of twisted off manifold bolts,ruined O2 sensors not to mention the clamps and hangers that are rusted firmly in place. There are some "Transmission Stop Leak" products out there that MIGHT work. In the old days we dumped a little brake fluid in there which softened the seals(?) and once in several thousand applications actually helped. We sometimes dump a Lucas product in the school bus tranny's and the boss seems to think it helps. These are 200,000 mile plus Allisons and they need all the help they can get!
In your shoes I would drive it and keep an eye on the fluid level. When it gets too bad take it to a good shop, and have the tranny rebuilt while it's out of the car. Maybe hang on a new exhaust system at the same time. my $.02
Ron

 

Thanks Ron,
Sounds like a plan to me. I checked it today and there is litterally no movement in the fluid level. Will keep an eye on things, after all she is 20 years old, she has to have a leak or two along the way.