Bravo Three Drive (SN:0W958159) Shaft Bearing Assembly

[RonJNash]

Hi,
Just fitted new Bearings to my original Bravo Three Drive Shaft and have set the preload for new Bearings. The issue I have now is when fitting the Drive assembly into the housing I find that the pinion gear is tight and binds when tightening the Retainer Nut. I read that the drive shaft may need to be shimmed, current assembly has no Shims. Cannot find any detail related to this in the service manual #28. Reason for bearing change was that initially I over tightened (Preload) ft -lbs instead of inc -lbs, so thought may as well renew bearings.

 

[alldodge]

Assuming you have not replaced the clutch assembly bearings and your only did so in the drive shaft.

There are no shims on the drive shaft but there is a spacer. On page 3A-38 illustration shows spacer g and how it is oriented. The parts have specific patterned for each part, the items must be free to move prior to installing the preload nut.

The clutch assembly needs to have the timing marks aligned prior to installing the drive shaft.

Are your bearings and races Merc/Quicksilver or after market?
Nothing wrong with after market so long as they meet the specs

 

[RonJNash]

Hi AllDodge,

The bearings are OEM Mercruiser New type but same as originally fitted. There is no spacer the Spacer is part of the first Bearing Race. The Preload was set to 1 NM for new bearings, however, how far the pinion gear goes in would seem to be governed by the first bearing race flange as this flange buts up against the lip in the housing. So it looks like a shim needs to be fitted up against the hosing lip to hold the bearing race back. The document that came with the bearing Kit sates that the bearing kit (Mercury Marine) needs to be fitted using the Special Tool 91-865114A01. Document also states - Kit contains tools needed for shimming the Bravo drive shaft housing. So I assume this is shimming the housing shim wold fit over first bearing between race lip flange and lip in housing. Can't seem to find any other detail online for this procedure.

 

[alldodge]

Looked up your serial number (I should have done that first) and you/we need manual 39.
In manual on page 3B-14 it does show a shim (item 42) which would be used for pinion depth

http://162.144.28.33/lib/mercruiser/manuals/mercruiser39.html#/204

Preload with new bearings is 6-10 in-lb, old bearings is 3-7 in lb, and preload is done with the driveshaft in the housing, not using the wrench

Pulled some stuff together

 

[alldodge]

And some more of it



The rest of the manual starts here using the shim tool

http://162.144.28.33/lib/mercruiser/manuals/mercruiser39.html#/306

 

[RonJNash]

Hi AllDodge, Many thanks for the excellent response, appreciated. This is what I thought was required but not really sure. This confirms what is required. Great Forum!

 

[RonJNash]

Hi AllDodge, Following your excellent response and attached information adding the shim sorted the issue. Many thanks your a star