lower unit rebuild

jimbos

Recruit
Joined
Jun 21, 2015
Messages
4
Made a big mistake did not check gear oil on a used boat( grumman 19 foot super fisherman) I purchased last fall it has DT75 ser. 07501-708717 I think it is 1987 when I took it out this spring the pinion bearing in lower unit locked up. I have removed unit and disassembled it gears are all good I ordered all new bearings and seals, pump impeller. Has anyone had any success rebuilding one of these? I own a auto repair shop and have rebuilt differentials for the vehicles any thing I should know about setting it up?
This boat sat and I have had a lot of issues getting it to this point it was taken to a marina before I purchased it and carbs were cleaned and I was told it was ready to go but when I ran it last fall the water pump was shot replaced that and when I got around to taking it out this spring it would not come up on plane found carbs full of varnish cleaned carbs, fuel pump,reed valves, filters, removed plastic in hull tank cleaned it, replaced all fuel lines ran good when I took it out then this happened.
 

jimbos

Recruit
Joined
Jun 21, 2015
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4
I do have a manual that purchased as a PDF and it gives all the info for setting gears up it is similar to setting up an automtive differential
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
If only changing bearings and seals and there was no damage to the housings you should be able to keep track of the shims and put it all back and it should be fine, IMHO
Swapping housings is where you have to look into shimming to get proper specs.
the machine work in the housing is never the same, but bearings and races are usually in good enough tolerance
 

jimbos

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Joined
Jun 21, 2015
Messages
4
Got lower unit all back together and all is well only issue I have is a slight grind when going into reverse don't seem like a big deal
 
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