Gear installation AlphaOne

[affa]

Hi
I`m replacing my bearings on the drive and driven gear on my AlphaOne 86mod, my manual doesn`t say anything about how to set the rolling torque, does anyone know how to do this?
Regards
Affa

[Technical Support]

Affa,
To set the rolling torque correctly you need to first press one bearing on, then put the large spacer, and then press the second bearing on. Do not press the second bearing all the way on. You want to leave it so you can still move the large spacer freely. Then install the gear back on the the u-joint assembly. Now you need to hold the u-joint assembly from turning, while tightening the nut. What you want to do is just tighten the nut enough to get 6-10 inch lbs of rolling torque, while making sure that the large spacer stays centered between the bearings. You really need to use a dial torque wrench to do it accurately, and remember to put some loctite on the nut.
It would be a good investment to get a Mercruiser service manual. Any Mercruiser dealer should be able to order you one. There is alot of specs that need to be right in the upper housing, or you will have nothing but problems.
Good luck,
Tech Support

[affa]

Thanks!
I got the manual that covers this to 1991 mod, and it doesn`t say anything about this. Guess I need a newer manual then?
Should I clamp the bearings when I check the rolling torque, so the u-joints and gears will go round?
Regards
Affa

[affa]

Hi again
I was maybe a little quick with my questions...
If I get it right I need to check the rolling torque which will increase the more I turn the locknut, right?
I have a piston ring compressor I can clamp the bearings and spacer with, and my manual shows something with a fishline around the drive shaft to check for preload, maybe I can check the rolling torque on the piston ring compressor the same way?
Thanks again
Affa

[Technical Support]

Yes, you can use a piston ring compressor to hold the bearings and spacer in place. If you have the tool to remove the large retaining nut, you can put that in a vise and set the u-joint and gear assembly on it. Use a large screwdriver through the U-joints to stop it from turning. Then tighten the nut slowly. Basicaly as you tighten the nut, it pulls the back bearing closer to the front bearing increasing the rolling torque. Then to check the rolling torque you hold the bearing from turning while letting everything else turn. You lost me on using fishing line to check the rolling torque. You need a dial torque wrench to do it properly.
Tech Support

[affa]

Hi and thanks alot.
Since I don`t have a dial torque wrench, I was thinking off putting a rope or a line around the u-joint drive splines, and measure with a fishing scale how much I need to pull before it starts to turn.Could that work?
Regards
Affa

[Technical Support]

I saw on another forum that you were replacing your bearings, but not the gears. Do you know if the bearings are a slip fit on to the old gear?
Tech Support

[affa]

Hi
I had to hammer the old bearings off, they sat real tight, I haven`t been working on those bearings before, and don`t know if it`s a slip fit, how can I check?
But i found a crack on 3 teeths on the gear, so I guess I`ll have to replace the gears as well.
Regards
Affa

[Technical Support]

Well, the new gears will definately be a press fit then. You really should try to find a dial torque wrench for setting up the rolling torque.
Good Luck,
Tech Support