Mercruiser Alpha 1 Gen 1 upper seal bearing pre load

othelloears

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I had the upper seal go on my Alpha drive and am compiling all the tools and parts for a weekend project. Its a SEI drive and has the "new" bearings without the spacer. Ive read everything and watched the videos and believe I fully understand the bearing preload procedure. My one question is whether I should bother splitting/seperating the bearings before I preload them. It seems like they are fine now and as long as I don't overtighten I should be fine starting where they are. Yes, I did buy the dial torque wrench which will be on ebay next week if everything goes right:)
 

tpenfield

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Yes, if you are below the rolling torque spec before you do any tightening, then you should be fine. If you over tighten, then you will want to take it apart and start over.
 

boatnut74

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If it doesn't have the small spacer (press fit) then it is 6-10 in lbs rolling torque.
 

othelloears

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HELP! I checked the rolling torque and it was 2.5. I barely tightend the nut and now the bearing is now completely locked...can't spin at all. 2 questions. 1) Can the bearing be locked just from over tightening or is there something else wrong and I need new parts and 2) how exactly do I split the bearing pack?
 

tpenfield

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How much did you tighten it? should be like 1/8 of a turn at a time, then re-check the rolling torque.

If the bearing is rusted or worn or defective, then it might lock up once it is tightened.

This is how you separate them . . .

bearingsplitter.png

It is a bearing splitter and it will wedge apart the inner races of the mated bearings. You probably need the bearings to separate a wee bit, not much (1/32")
 

othelloears

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I am confused. I bought one at harbor freight and all it does is squish the ring in the middle. I assumed from the picture it was supossed to wedge in between the ring and bearing and spread them apart. Is that correct?
 

othelloears

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I was finally able to get everything apart. It actually worked out better because there was some rust and corrosion inside the bearing which I couldn't see. I just ordered the bearing set to replace.

So after reading the online directions it looks like I've got to press the first bearing all the way onto the pinion then press the second to get my rolling torque for new bearings of 6-10.

My only question now is how do people press these bearings? (hammer down with socket, screw down with bolt)
 
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Have you watched Chris' video on the job?

My guess is your going to have to get your hands on a shop press to get that bearing on. Harbor Freight has a sweet 20-ton that goes on sale for 150.00 with the coupon. Been eyeing that baby now for a while.... just gotta make room for it first.

I don't think a hammer/socket is going to be a good way to do it.


 

tpenfield

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I was finally able to get everything apart. It actually worked out better because there was some rust and corrosion inside the bearing which I couldn't see. I just ordered the bearing set to replace.

So after reading the online directions it looks like I've got to press the first bearing all the way onto the pinion then press the second to get my rolling torque for new bearings of 6-10.

My only question now is how do people press these bearings? (hammer down with socket, screw down with bolt)

IMG_4393.jpg


You got to go over to Harbor Freight and get yourself a 10 ton press. Then you can get some PVC or metal pipe couplers of the appropriate size to use to press the bearings onto the gear using the inner race. Then the spacer and the second bearing gets pressed on but not quite touching the first bearing so that there is no pressure on the bearings.. (If I recall correctly).. You can always refer to the Mercruiser manual for details.

IMG_4395.jpg


Here is the whole business loosely assembled and ready for setting the rolling torque

IMG_4402.jpg


Setting the rolling torque with the Seekonk Torque gauge . . . you are tightening the nut on the drive shaft assembly in small increments and then checking the torque (1/8 or 1/16 of a turn at a time)

IMG_4409.jpg


SInce mine were new (and it sounds like yours will be), I set them to the higher end of the Spec range, figuring that they would wear-in a bit and loosen up . . . If they were not new, I would have set them towards the lower end of the range.
 
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othelloears

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Thanks. I'll look into harbor freight.

I am reading the manual re: shimming on install. If I am not changing the gears or shaft do I have to worry about new shims or can I go with the ones that were in there?
 

tpenfield

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Thanks. I'll look into harbor freight.

I am reading the manual re: shimming on install. If I am not changing the gears or shaft do I have to worry about new shims or can I go with the ones that were in there?

The ones that are there should be fine.
 
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