assemble Alpha 1 gen 2 lower unit issue

Sashap

Petty Officer 2nd Class
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May 1, 2016
Messages
145
When I put in the new bearing carrier and just hold it in place by hand, the prop shaft and vertical shaft appear to operate normally. When shifting the lever, it changes direction correctly and smoothly. However, when I tighten the prop shaft with the big nut, something binds up and I can't turn the vertical shaft. It appears to be binding on something. I can't figure out what is wrong. Ideas?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Vertical shaft is called the 'lower drive shaft'.
Are you just replacing the carrier or did you fully or partially strip the rest of the housing? Did you put the same shims back in that came out?

Chris.
 

Sashap

Petty Officer 2nd Class
Joined
May 1, 2016
Messages
145
I am using a brand new fully assembled bearing carrier. The old bearing carrier was cracked.
 

Sashap

Petty Officer 2nd Class
Joined
May 1, 2016
Messages
145
Also, I did verify the pinion gear was shimmed properly using the shimming tool.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Using the old (reverse gear) bearing and its shim?
 

Sashap

Petty Officer 2nd Class
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May 1, 2016
Messages
145
The bearing carrier was supplied completely assembled. All new parts, including the gear etc.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Did you do a backlash check on the reverse gear(to pinion)? If you've installed the new carrier without shimming, that's why it's locking up. The starting shim is 0.5mm, and adjustment is usually only a few thou either way.

Chris......
 

Sashap

Petty Officer 2nd Class
Joined
May 1, 2016
Messages
145
Found the issue. I compared the gear to the old one. Way different size. The new gear was a good 1/2 inch smaller. So I pressed out the old gear/bearing and the new gear/bearing and put in the old gear/bearing. The condition of the old gear was excellent and the bearing was not removed from the gear itself so all is good now! Put it together and it works perfectly. Pressure tested and all is good. Thanks to all who offered help!
 
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