Pulled gearbox, questions on evidence of leak and seals

audiocontr · Post by **audiocontr** » Mon Jul 05, 2010 8:04 pm

Thanks for everyone's help in removing my gearbox from the 710. Its out and I'm studying it for signs of which seals need replacing.

Question 1: I noticed thick black oil accumulation within the bell that surrounds the clutch. I'm wondering how can I determine if its a leak of the rear main seal of the engine (behind the clutch) OR the front seal of the gearbox (behind the clutch engagement fork)?

Question 2: Is it possible a leak could come from some other point and leak into the bell? I noticed it is wet with oil at the base of the fuel pump, but i wouldnt think its enough to drench the inside of the bell, plus leave quarter size spills on the ground. How could i tell if its engine oil vs gear oil vs brake fluid?

Question 3: I noticed gear oil leaking from the rear of the gearbox, where i disconnected the drive shaft. I need to replace that seal. Would someone be so kind to tell me the part numbers needed for new gearbox gaskets? I have the diagram but im afraid I am missing something. The diagram just does not look like the gear box.

Question 4: As i rotated the gearbox, gear oil came out of a small nipple at the very top of the case, next to the box that you connect the shift selection arm to. As a matter of fact, its 2 inches forward of that portion of the case. It had a rubber cap on it which i did not remove. Is this something that I should just leave as is?

Question 5: In order to replace the two main seals at each end of the gear box, will I need to replace other gaskets to get to it? If so, which so I can order everything at one time.

I really appreciate your help here.

-Will

audiocontr · Post by **audiocontr** » Wed Jul 07, 2010 2:52 pm

Sorry to be a nuisance. Any ideas here guys?

undysworld · Post by **undysworld** » Wed Jul 07, 2010 4:05 pm

Hi Will,

Sorry to leave you hanging. I assumed other, wiser, folks would chime in. But, here goes:

1) Without active leaking going on, I'd say you've got to go on the evidence. The oil will (generally) be flowing downhill, so where-ever you see oil, start looking upwards. I'd think in the event of a rear main seal, you'd find oil between the flywheel and block. The opposite for the tranny.

Cleaning the area, and running the machine, and then looking for fresh leakage is ideal, but then you'd have to put it all back together again...

But your 2nd question might solve that mystery.

2) I'm not familiar with any other possible sources of leakage in there, but perhaps others are. Oils will float on top of water, I assume brake fluid won't as it absorbs water. Engine oil will smell like the inside of your engine (oil fill tube), gear oil just plain stinks bad. Ask any local mechanic to let you sniff gear lube and you'll appreciate the difference.

3) I don't know off-hand, and my manuals are not here right now.

4) Ditto #3, dunno. Vent?

5) Can't help here either, sorry. I haven't had to do this yet. It's possible one of the vendors could tell you this info maybe?? Generally, I've had to rely on the manuals.

Best of luck.

audiocontr · Post by **audiocontr** » Wed Jul 07, 2010 5:10 pm

Much appreciated =)

I have a feeling i will replace the main seals on the transmission and hope that fixes it!

ahhhh. hope