Alpha One Upper Drive Shaft

[lappa]

help
resealed upper drive shaft housing changed bearings time to re assemble question.
what is the tourge setting for the pinion nut i tourged to 85 ft lbs like the manual says now i can not turn bearings. anouther manual says 6-10ft lbs can anyone tell me what im doing wrong? and if i did any harm to bearings if i messed up at 85 ft lbs .
1990 alpha one 5.7 260
thanks

 

[Don S]

Re: Alpha One Upper Drive Shaft

What manual do you have?

Now I know about the 6 to 10 ft. lbs you talked about. That is INCH POUNDS, not ft lbs. and is rolling torque, not torque on the nut.
You get the rolling torque by tightening the nut just enough.
Follow the steps under the heading Reassembly without Small Spacer: starting on page 3A-19 of this link. Click Here

Especially read the note on page 3A-20 that reads.

IMPORTANT: If while accomplishing the preceding
procedure the preload goes over the specified
limit of 6-10 lb. in. (0.7-1.1 N?m), the bearings
must be totally separated from the gear and reassembled
following the appropriate previous
instructions starting with “U-Joint Assembly,”
‘Inspection and Disassembly’ section found
page 3A-8. Failure to follow these instructions
will cause premature failure of the unit.

 

[lappa]

Re: Alpha One Upper Drive Shaft

selco manual
out drive serial # OC778667
THANKS

 

[Don S]

Re: Alpha One Upper Drive Shaft

Re-read my previous post. I added to it after I asked what manual.
Then throw that seloc away.
Use the OEM manual only.

Here is a link to the complete manual. Scroll to the outline and click on the section you want to read.

http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf

 

[lappa]

Re: Alpha One Upper Drive Shaft

I Seem A Little Stumped
That Manual Says 6-10 Inch Pounds Then Tells That The Pinion Nut Letter E #25 Gets 70 - 80 Ft Lbs Im Confused.. Also How Do You Calculate Rolling Torqe
Matt

 

[Don S]

Re: Alpha One Upper Drive Shaft

That Manual Says 6-10 Inch Pounds Then Tells That The Pinion Nut Letter E #25 Gets 70 - 80 Ft Lbs Im Confused..

Read ALL of page 3A-19. There are 2 ways of doing the job, and it depends on the bearings and spacers you have.

Also How Do You Calculate Rolling Torqe

You don't calculate rolling torque, you read it off a torque wrench.

You REALLY need to read and understand the process before you do it, not just pick a few pictures out of the manual and try to do the job.

 

[flyinghi5]

Re: Alpha One Upper Drive Shaft

I agree with Don S...be very careful with the preload and if you go over specified torque, disassemble and do it over again. I have not done one on the MerCruiser but it is the same style of gear assembly as the rear axle of a vehicle. You will slowly put torque on the pinion nut (the one you are thinking should be 80 lb. ft.) and then you will check the preload of the you just put on the bearing by now using a torque wrench calibrated in inch pounds. You will put the inch pound torque wrench on the pinion nut you just tightened and use it to turn the pinion while looking at your dial reading on the wrench. If say you are at 3 lb. in. you would use your lb. ft. torque wrench to tighten the pinion nut just slightly more then remeasure preload again. Do this procedure over and over until you reach the 6-10 lb. in.

good luck

 

[Ryan00TJ]

Re: Alpha One Upper Drive Shaft

I've rebuilt a few Alpha's now and it's pretty easy with the right tools and a #6 manual. If you have the driveshaft bearing retainer wrench it makes it very easy. Put the wrench in a bench vise along with the assembled driveshaft assembly splined shaft pointing down. Having a large breeze clamp around the two bearings and races and gears keeps everything together. Add the pinion nut, I use blue locktite. Use a large screwdriver or punch to put through the Ujoint flange to keep the assembly from turning. Tighten the pinion nut with a ratchet until you get the right torque. Then move to your " lbs torque wrench. You can usually take off the B clamp now. Holding the bearings by hand spin the assembly with the torque wrench checking your reading. Keep tightening the pinion nut until you reach the desired torque. Off the top of my head new bearings are 6-10" lbs while used are 2-4"lbs. Check the manual on those specs for sure.

I've always used new bearings are set them around 8 "lbs with no problems.