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Lower unit oil overheating causing seals to fail.

B

BJK

New member
For two seasons the oil in the lower unit has overheated and seals have failed. No one local seems to know the cause. The smell of burnt oil is evident. I have a Bravo 3 outdrive. :confused: I would really like some help so I can direct the mechanic toward a course of action.
 
kghost said:
Drive shower...google them...
Click to expand...
Thanks for the reply but I don't think that's the answer. The boat is a 1999 Parker 25'. Why would I now need something the boat didn't need for 15+years? I think it would help but I don't think it will correct the cause of the problem; whatever that is! Thanks, again. BJK
 
What gear lube are you using?

Are the seals being replaced Mercruiser or aftermarket like Siera brand?
 
Not sure on the seals as I didn't do the work. All the gear lube that I have added is Mercruiser. Thanks for giving this some thought. BJK
 
Try to give any and all information. Hate to ask basic questions over and over.

So based on your responses.......what has changed in the last two years that may have caused this issue?

COMPLETE HISTORY ON THE BOAT!!!!!!!!!!!!!!!
 
Your issue is probably a flow problem.....There is no pump in the drive but...The gears cause a negative pressure to occur and hence move the gear oil between the upper and the lower. I removed a one inch square piece of paper towel from the lower on a B3 and it burned up the drive.

The seals failing because of High temp is a reach.
 
More likely, seals fail ( seal seating surfaces OK???... shaft scored?) water gets in, oil/water emulsion not a good lube.... then it overheats.
 
Need to know what engine pump, water pickup type , If you went to a thru hull and capped the water inlet thru the transom you not flowing water THRU the drive.
 
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