Pressure test results found the leak now what..

[sheboyganjohn]

Did a pressure test on one of my MC-1 outdrives from my 73 sea ray. At 8 psi it started leaking where you could hear it and would leak down to 5 psi and stop. Found the leak on the drive shaft between the lower and upper half. Separated the halves and found the oil seal had a tear in it. Did some reading on here and from what I can tell if the lower one is leaking, the upper one is also leaking. So I am guessing that means I should change both of them. I have copy of both manual 1 and 2 (thanks to the guys that provide the downloads for them). However the manual tells you how to completely disassemble the drive down to the last shim. If I am just replacing the two oil seals, can I just remove the main imput drive (the one with the u-joints) pull the upper drive shaft out of the housing, replace the two seals, then put everything back in, or do I need to play around with gear lash and preload and all those other fun terms that tend to turn gears into metal shavings.

Thanks in adavance.

 

[sheboyganjohn]

Re: Pressure test results found the leak now what..

OK I think I found my own answer. Looking over the manual a few more times, it looks like the oil seals can be changed with-out removing the lower bearing cup for the driven gear. If I leave that in place the only detail I need with the gears is to make sure the timing marks are lined up between the drive and driven gears, the preload should not change on any of the bearings. Correct me if I am wrong.

 

[achris]

Re: Pressure test results found the leak now what..

OK I think I found my own answer. Looking over the manual a few more times, it looks like the oil seals can be changed with-out removing the lower bearing cup for the driven gear. If I leave that in place the only detail I need with the gears is to make sure the timing marks are lined up between the drive and driven gears, the preload should not change on any of the bearings. Correct me if I am wrong.

The only gear-set to have timing marks is the 1.65:1. What engine is this drive behind?

 

[sheboyganjohn]

Re: Pressure test results found the leak now what..

The drives are behind 140's.

The manual did not state a specific gear ratio, just said drives with the same number of teath on both gears, guess that is not mine.

 

[achris]

Re: Pressure test results found the leak now what..

The drives are behind 140's.

The manual did not state a specific gear ratio, just said drives with the same number of teeth on both gears, guess that is not mine.

Actually the manual did mention a ratio, the one with the same number of teeth... Because there were 2 different lower units that could go on those uppers, they can't mention the numeric value...

As you have a 140, the ratio should be 1.98:1, and they don't have the same number of teeth on drive and driven gear...

Chris.......

 

[sheboyganjohn]

Re: Pressure test results found the leak now what..

That makes sence.

Just need to wait on my spanner wrench seals and I will tear into it. Maybe while I am waiting I will drain the other lower and dothe pressure test on that one. I'll just leave that one in one peice, don't need to turn both units into a stack of parts at the same time.