1972 Mercury 140 lower gear case

[irongenny140]

I just bought this about a month ago. It is on a 1972 16 foot checkmate. We lost reverse and I then noticed a lower gear oil leak coming from a big pin hole on the front of the bullet. Did we shoot reverse through the case? Fixable??? I am thinking I am now looking for a lower gear unit. It has a bad skeg and another chunk missing as well. Perhaps there is a dead one out the with a good gearcase? We also have a broken motor mount thanks to my son's WOT turns in rough water. Thoughts?

 

[daveswaves]

Re: 1972 Mercury 140 lower gear case

I just bought this about a month ago. It is on a 1972 16 foot checkmate. We lost reverse and I then noticed a lower gear oil leak coming from a big pin hole on the front of the bullet. Did we shoot reverse through the case? Fixable??? I am thinking I am now looking for a lower gear unit. It has a bad skeg and another chunk missing as well. Perhaps there is a dead one out the with a good gearcase? We also have a broken motor mount thanks to my son's WOT turns in rough water. Thoughts?

Likely the shift dog is rusted due to water intrusion through the pin hole. The actual gears may or may not be OK, depends on how long they sat corroding in water. As for the broken motor mount it should have been able to stand up to turns at any speed. Likely it was cracked or damaged previoulsly. It just happened to break when stressed. Sounds like you are looking at a replacement gear case. They do come available on ebay. Check the gear ratio of your 140 before getting a replacement. Most used gear cases are 2:1 ratio, yours may or may not be, it may have been replaced . If you can post a picture of the broken mount it will be easier to help you with that problem.

 

[irongenny140]

Re: 1972 Mercury 140 lower gear case

Thanks.

The motor mount was previously welded. I think it would be better to replace than to try to repair. I will be watching ebay for another 140HP. Either the parts or a whole motor with a bad powerhead.