A1 G2 upper unit bearing part numbers

willett

Cadet
Joined
May 24, 2011
Messages
23
Picked up a leg from a neighbour to replace my blown up leg. Upon inspection of the upper unit I noticed the bearings have been sitting for a few years with moisture intrusion. I need to replace the upper unit bearings.

Does anybody on her have TIMKEN,SKF, F A G, or similiar MFG part numbers for these bearings? I don't have a guillotine at home and I would like to get these suckers ordered up today.

Also I'm assuming that the gear reduction happens in the lower leg as both gears in the upper unit havea 25 tooth count. Can somebody verify

Thanks
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Picked up a leg from a neighbour to replace my blown up leg. Upon inspection of the upper unit I noticed the bearings have been sitting for a few years with moisture intrusion. I need to replace the upper unit bearings.

Does anybody on her have TIMKEN,SKF, F A G, or similiar MFG part numbers for these bearings? I don't have a guillotine at home and I would like to get these suckers ordered up today.

Just remove the nut off the end and pull the bearings off. The numbers are on the edge of the races. No requirement for a guillotine.

willett said:
Also I'm assuming that the gear reduction happens in the lower leg as both gears in the upper unit havea 25 tooth count. Can somebody verify

Incorrect. The ratio in the lower is fixed at 1.62:1 (yes, there are a few exceptions, but mostly, ok ;)). The upper is the one that gets the different ratios and drives the overall ratio. Your upper with 24:24 (recheck your count) means the total ratio is 1.62:1... So I'm guessing you've got that behind a V6....(4.3 litre). If the ratio was 1.47:1 (used for the V8's), then the upper would have 22:20, or for 1.94:1 (used behind the 3 litre engine) would be 20:24....

Chris........
 
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willett

Cadet
Joined
May 24, 2011
Messages
23
Thanks for the info. Your right. 24 teeth not 25.

The bearing numbers are all on the inside except for the outermost bearing.

This is bad news about the ratio as this leg will be going behind a 260hp 5.7

I guess I'll be going 10% slower for now :|

Do you think it would be possible to swap in the old upper gears from my old Gen 1?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Thanks for the info. Your right. 24 teeth not 25.

The bearing numbers are all on the inside except for the outermost bearing.

Remove the nut off the end of the yoke and pull the bearings apart. Once there are all off, then you have access to all the numbers...

willett said:
This is bad news about the ratio as this leg will be going behind a 260hp 5.7

I guess I'll be going 10% slower for now :|

Not really... Just prop up a size....

willett said:
Do you think it would be possible to swap in the old upper gears from my old Gen 1?

No... And even if they were the same, the tools needed to set them up are EXPENSIVE!

Chris........
 
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tednv

Seaman
Joined
Aug 6, 2012
Messages
60
a gear job on a stern drive is no fun. if I needed one I'd probably get an SEI aftermarket drive for ~$1500 and call it a day. Too many special tools needed, very small tolerances, and high probability of failure if it's not something you've done before
 

willett

Cadet
Joined
May 24, 2011
Messages
23
Thanks for the input. Stripped everything to the point of the bottom bearings but didn't want to yard on the cages too hard. Wasn't sure how tight the bearings were going to be. Had to lay some heat on the bearing closest to the nut to get it to pop off.

I'm a ticketed mechanic and I've done lots of rear ends. Just new to all this marine stuff.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Simple press and a press plate is all that's required. Do you have the procedure to fit the new bearings?
 
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