Tracking down a tranny leak

So I've been having a very small manual transmission leak, or so I think, on my '01 3.4 4WD for the past year or so. I initially thought there was either some spill or overfill from a clutch replacement, but now I'm not so sure. There was a thin film of fluid covering most of the tranny, so I've washed it all off with degreaser and the entire bell housing is pretty clean now. I'm goign to try to track down the source, but I'm afraid I'm not exactly sure where I should be looking. Anyone have any experience tracking down small leaks and have any tips for me? I definitly haven't noticed any problems shifting, and everything seems to be fine. Should I even worry about it, or just make sure to keep the fluid level topped off if it ever gets low?

Thanks guys!

 

You definitely started off right by washing and degreasing it to start. Given the severity and how slow the leak appears to be, start by putting a (few) hundred miles on it and climb back under for a recheck. It'd be helpful to have one of those mirrors with the extendable handle and folding/angling mirror so that you can see any seals or mated surfaces on top of the tranny as well.

If you are still unable to find the exact source, or if fluid appears to be coming from more than one area, you can try adding UV dye to the system and running it again, then rechecking with a black light. Most parts stores have kits for this or you can source it yourself, but either way, I've had to go this route before when tracing a slow leak.

Good luck!

 

Thanks for the tips! I'm hoping I won't have to use them… I went ahead and checked the fluid level just for fun, and as soon as I took off the filler cap, about half a quart of oil came pouring out of the filler hole. Best guess is that during some service done somewhere a well-meaning mechanic way over-filled my transmission. Not quite sure how they managed to get that much fluid in there though… Best guess is that it's been spilling out the breather on the top? It does seem like there was quite a bit of oil and grime on the top of the bell housing. So I drained it down to the point it was level with the fill hole, hopefully I won't see any more leaking. It does kind of make me feel dumb for not checking that first, and also makes me grumble a bit about the quality of some of the random oil changes and tune ups I've had done while on the road when I was too busy.