Gear oil leak, 2000, 90hp lower unit

[Jburke4689]

I was doing some maintenance on my lower unit. I replaced the water pump assembly, the propeller shaft seals and the bearing carrier O-ring. The unit was not leaking before I did the work. It was just 14 years old and I was doing preventative maintenance. The unit was filled with oil and I laid it down on its side where it sat for three weeks. When I lifted the unit upright today about one ounce of clean gear oil leaked out of a small vent hole in the side of the gear case and the water intake.

Nothing is coming out of the seals I replaced and the ones I didnt replace (driveshaft and shift shaft) weren't leaking before. The unit isn't overfilled.

My question is whether it is normal for some oil to leak as described if a lower unit is laying on its side for several weeks. I plan on pressure testing the unit before reinstalling it. Thanks

 

[racerone]

Re: Gear oil leak, 2000, 90hp lower unit

This motor has a 2 piece driveshaft.-------It can leak when laid down on the floor because the driveshaft is not centered.-----------Pressure test again.

 

[boobie]

Re: Gear oil leak, 2000, 90hp lower unit

You should have replaced the drive shaft and shift rod seals.

 

[Jburke4689]

Re: Gear oil leak, 2000, 90hp lower unit

You should have replaced the drive shaft and shift rod seals.

Are you saying that the fact that it has a 2-piece driveshaft and was laying on its side for 3 weeks has nothing to do with the leak?

 

[TD_Maker]

Re: Gear oil leak, 2000, 90hp lower unit

The two piece driveshaft drove me crazy too. I was confused because the upper drive shaft flexed so much, and this flexing made the drive shaft seals leak. When I installed the impeller and water pump housing (tightening everything up) the drive shaft seals no longer leaked. When the lower unit is bolted to the powerhead, everything stays center aligned and sealed up. Racerone is correct. Pressure test/vacume test it again while the unit is vertical and the drive shaft is supported. I will bet the weep hole oil is a non-issue.

I bet Mr. Boobie was suggesting that since you replaced the water pump impeller anyway, it would have been easier to dig a little deeper under the water pump base and replace the drive shaft seals just for good measure.

Mr Boobie and Racerone are very good on this forum. Listen to them.