Recently took my car to a shop to have the c4 rebuilt. Get the car back and it shifts AWESOME. Two days later I notice an oil puddle appearing under the transmission that was never there before. I start looking around and can’t find anything near my first though (valve cover). At this point, I’m beginning to think it’s a bad rear main as it only happened after putting the transmission back together. I’ve watched videos and read forums on how to do the process with everything still connected. My question is, do ya’ll think there’s any way it’s leaking from somewhere else?? The leaking doesn’t seem to be coming from anywhere on the top and it drips out a lot whether I drive the car and it thins out or it sits for a couple weeks in the garage. Really wanting to finally drive my car again. TIA.
Is the puddle oil or transmission fluid?
Definitely oil.
You did not mention which SBF engine you’re running or how many miles or age.
Original was a 2 piece RMS that can be done with the oil pan removed. Isn’t a difficult job but does require care not to damage the upper half of the new seal when it’s rotated in place (easily cut/shaved by the engine block knife edge) and - of course - it is directional and will leak badly if installed backwards.
Late model blocks went to a 1 piece RMS which would be a lot more work given the need for access to the rear of the crankshaft.
A leaking oil pan, intake manifold or valve cover are also prime suspects. Sometimes hard to see where I’ve had to resort to a UV dye added to the engine oil and light in a dark garage to absolutely identify (I once had a cracked oil dipstick tube base that drove me crazy for months and that is how I found it).
More unlikely are the oil galley plugs at the rear of the block and the rear cam plug. I mention them simply to make you aware but I have never seen these leak on an engine of mine and I’ve had plenty over the years.
Good luck.
Jim
It’s the factory 302 and c4. Mileage unknown. I’m leaning towards RMS simply because it only happened once popped apart. When the car was on the lift and trans was out, I stopped by and saw no leaks. Car only leaked after I drove it the 45min home the day I picked it up. Now, I’ve cleaned three huge puddles up from under it and can’t find anywhere obvious it’s leaking. Currently leaking.
I seem to have this same issue with my 1968 XR7 GT. It only leaks (small leak) when it has been running. Once if has been parked a while the leak will stop. Everyone seems to think it is the rear main seal. I would agree but I it has been replaced twice in the past few years.
As mentioned earlier the rear oil gallery plugs or the cam cover can leak as well. Since the transmission was involved I would focus on the rear main seal. It can be done without the transmission removed but it is a real chore.
I was thinking it had to be seal as it happened when I drove and it parked. Once I noticed the puddle keeps happening whether I drive or not, I started rethinking my diagnosis. I don’t want to have to pay labor to take it apart and replace it as I can’t blame the shop for it going bad at their fault. I got everything I’ve seen recommended for the job (sneaky Pete, etc.) but, want to see what others thought about possibilities before I cause a new problem.
IMO you should determine where the leak is coming from before you pull it apart. If it leaks when running then get it on a lift. I wouldn’t be afraid to see if the tranny rebuild shop would help take a look at it. Valve covers can leak a bunch of oil too. Hard to see from your pic where it might be coming from.
After a 2nd look at your pic- if your drip pan is where the leak is then it’s a transmission leak. Could be shift lever seal leak as those leak pretty good on a C4. That seal is on drivers side.