OMC Stringer Upper Gearcase Pinion Bearing Preload

[imported_Gary L]

I am working the upper gearcase on a 1980 low profile 800 stringer mechanical shift drive used with a 5.7 liter Chevy. I was replacing the water pump and found the spines were bad between the drive shaft and the water pump shaft. I have the new shafts and seal kit etc. but my question is about the preload on the bearing housing bearings. After replacing the drive shaft that the water pump shaft fits into and using the same bearings and shims the fit seems to be very "sweet" to me. I don't have a 0 to whatever inchpound torque wrench. There is no play at all and not too much resistence. Do you think I'm ok without buying the torque wrench or pressing the bearing off and removing a shim to see if it is too tight? Thanks again for all the good infor I get from the forum. Gary

 

[supercab78]

Re: OMC Stringer Upper Gearcase Pinion Bearing Preload

I did mine like that 17 years ago, no problems. I had to do it again (rust) 2 years ago. I had a inch # torgue wrench this time. If I remember correctly there was some preload on the top bearing. There was a bit of resistence when turning it by hand. Also in cause you didn't know you can use regular outboard gear lube in the upper gear case instead of premium blend..

 

[KaGee]

Re: OMC Stringer Upper Gearcase Pinion Bearing Preload

The shims are the important thing. There is a special tool to get the shim thickness. Unless you removed the bearing, in theory the existing shim should be fine.

I reused the shim on the bottom side, and since I did not have the tool, I measured the the shim thickness on the topside with my calipers for the correct replacements. They got tore apart when I pulled that shaft.