Drive bearing assembly -preload question

[supercab78]

Ok, here is what I've done and here is my concern. 1984 140hp, Mercruiser with a Jasper outdrive installed in 1999. I had gear oil leaking past the seal and into drive shaft boot. I replaced the drive gear yoke (new) and a new double lip seal into seal carrier. Upon assembly with the used bearings I used a hose clamp around the large spacer. ( I don't believe there is a small spacer in this unit). When I had the drive gear nut on but not even toughing the washer under it, I checked preload torque it already had 4 inch pounds. I continued to tighten the nut down until it was snug plus a little more and it is still 4 #s. When I removed the hose camp I'm able to move the large spacer that is between the roller bearing cups. Is it normal to move the large spacer if there is proper drive gear assembly preload? My concern is the preload is not enough. It's like I'm getting a incorrect reading because of the new double seal giving it extra drag. So I'm looking for input from some experienced people. Thanks

 

[Don S]

Re: Drive bearing assembly -preload question

Do the bearings turn perfectly smooth? Absolutely no roughness? If not, you need to inspect and clean the bearings. They must turn freely or the readings will be useless.
That front seal is NOT a double lipped seal. Just a single lip and there can't be an groove in the yoke where the seal rides
Now, if all that is right, you are probably seeing the rolling torque at 4 inch lbs. because of seal riding on the yoke and friction in the bearings. You need to set your torque wrench to 0 before tightening and tighten to specs above the friction.

 

[supercab78]

Re: Drive bearing assembly -preload question

Yes, smooth no roughness. The yoke is new, I realize must seals are single lipped but this one is double lipped. So keeping the 4 inch pounds as a base, maybe go up to 6 1/2 - 7 inch pounds? All at rolling torque of coarse. Since my first post I have tightened it some. It now has 6 " #,s. The large spacer between bearing cups can now only be moved sideways when tapped with a brass hammer. Before then I could slid it with my finger.

 

[Bondo]

Re: Drive bearing assembly -preload question

I realize must seals are single lipped but this one is double lipped.

Ayuh,...

Have you got a manufacturer,+ part # for that seal,..??

 

[supercab78]

Re: Drive bearing assembly -preload question

No manufacturer name is on the seal. As described on the wed site of supplier it's custom made for them. I probably shouldn't list the web site but the kit is called " A-Upper Drive Seal Kit Deluxe#1 Alpha". Part no. IMUS2 . I think all their seals are double lipped. Sorry for the delay in response, worked 24 hour shift with no i-net available.