78'105 Lower Unit Rebuild-pics-?'s

fishinrado

Petty Officer 2nd Class
Joined
Nov 8, 2006
Messages
137
hello all, creating a new post in connection with post titled ( 78 magna power -gear box ?'s) in hopes to continue to add to this forum. I have read many a post with issues regarding "clunking, griding, in and out of gear at wot, gear pop etc.....but did not see any pics to explain the parts in question. Thanks to "frank", who I hope will find this post, I want to submit a detailed new post with pics to name all of the parts in the lower unit and a step by step guide. Before I do so will someone please chime in to make sure I am not in error for mis-naming or for innapropriate procedure! thanks.....
I have removed the parts in the lower unit due to issues in that earlier post, please reference.
Enclosed are the first 3 pics to clarify:
1) worn reverse gear - notice the concaves in the inner circle causing the gears to slip by each other? actually creating a point where two 45 degree angles intersect.
2) the 6 worn legs of the dog clutch. some have started to be dremmeled back to square from right to left
3) the prop shaft with attatched dog clutch showing why the two worn parts create slippage when in gear.
 

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Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 78'105 Lower Unit Rebuild-pics-?'s

WOW! You have your work cut out for you. I rarely have seen that much damage to a gearset. last time was on an old '60s 45 horse.

You need to be careful to ensure that all three sets of dogs are ground so that they all engage. Just take your time and keep measuring as you go.

It would be a lot easier to take it to a machine shop but that's going to cost--a good bit, but less than a new gear set. On the positive side, it will be more accurate than you can get by hand.
 
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