Short version: is there anything I can do differently when two new input shaft seals both leak? Trans is a ZF 5 speed from E46/E36 M3. No obvious defects on input shaft.
Long Version: Trans in my E46 track car was craigslist sourced (donor car was an auto that I "converted"), so I don't know the history of the trans. Before putting it in the car for the first time, the detents, input, output, and selector shaft seals were proactively replaced with BimmerWorld kits using [presumably] OE quality parts. On shakedown run there was a puddle from bellhousing and input shaft was pretty obviously leaking. The seal was replaced with another the shop had on hand. Ran one session and leak persisted, though less severe. Shop didn't have anymore seals and I had a spare transmission that was also a marketplace/junkyard pull that hasn't been touched, so we put that in (this was all "day of" track event at VIR). Ended up with oil out of bellhousing again, but this appeared to be engine oil. So, either rear main had been also leaking this entire time, or with enough in and out's of the transmission, it somehow got monkeyed up. It was also fresh. I'm replacing the rear main now at my house, and would like to put the transmission with the refreshed detents back in the car, but if I spin it by hand, I can clearly see oil around the input shaft. So it's definitely still leaking. Any thoughts/tips/tricks, or is that transmission in need of some hard parts?
My guess is that input bearing is loose or input shaft is bent, possible missing or bad pilot bearing. Something preventing the seal from doing its job.
Trying to determine the exact source of a leak inside a bell housing can be a real bitch. Clutch whipping air around all over, can't see inside while it's running, all shiny and stuff. Input shaft seal will be distributing the oil onto the disc, in most cases.
Can you borrow a smoke machine to pressurize the engine or trans while the trans is out on the bench?
akylekoz said:
My guess is that input bearing is loose or input shaft is bent, possible missing or bad pilot bearing. Something preventing the seal from doing its job.
I figure the same, but pilot bearing is intact/new, and there's no discernible play in the input shaft. Granted, that's using the super high tech method of grabbing and shaking/spinning and eyeballing, so probably not really ruling anything out.
Streetwiseguy said:
Trying to determine the exact source of a leak inside a bell housing can be a real bitch. Clutch whipping air around all over, can't see inside while it's running, all shiny and stuff. Input shaft seal will be distributing the oil onto the disc, in most cases.
Can you borrow a smoke machine to pressurize the engine or trans while the trans is out on the bench?
In this case, 99% sure the answer was "all of the above". This was a fresh build, used/unknown motor and trans, that's only shakedown was a little bit of romping around the VIR complex/paddock, and otherwise went straight on track. Granted, everything got resealed, but I'm honestly pleased that this/these leaks were my only issues across two days of romping.
