[davidpaul]

One thing has become clear and that's how incredibly small the backlash clearance is. The manual says .1 - .2 I've got it to .4 at the minute, not an easy job to do.

[davidpaul]

Well here she is all rebuilt, refit and test next, report to follow

[Bobbed06]

As long as the tooth contact is proper, I would feel ok about a looser backlash spec, being to tight would possibly make it louder than the slightly looser setting. What backlash setting did you settle on?

Looks good, cant wait to hear the ride report!

[davidpaul]

around .3 - .4, the mesh looks good the backlash is set a new bearing on the crown wheel side, my fingers and toes are crossed hoping that I get the right result. Tomorrow should be test day 

[Bobbed06]

around .3 - .4, the mesh looks good the backlash is set a new bearing on the crown wheel side, my fingers and toes are crossed hoping that I get the right result. Tomorrow should be test day 

That sounds perfect, it will be more durable since its properly meshing now.

[davidpaul]

I have managed to get her up and running and the result's are....  around 25% improvement  when I was building her back up I wasn't convinced there would be any improvement.

To me she's now in the acceptable range, very happy

I only replaced one large bearing with a better quality item, it wasn't meant to be a no expense spared rebuild so all in all a good job done.
(bearing I replaced in picture 1)

I bought all of the different size shims (except the pinion shim) before I started, as it turned out the pinion didn't need any adjustment so the .60 shim she came with stayed in place. ( this only needs adjustment if the contact patch is in the wrong place, as in picture 2, picture 3 shows the shim you will need to adjust if the contact patch is wrong)

In the end the crown wheel shims were only .10 thicker that the standard .40 so it wasn't much more than she came with, maybe just some wearing in, I probably could have gone to .55 or .60 but I found it difficult to get a good reading so I left the backlash a bit on the wider side, it's still very small amount of play (.3 - .4 ish)
(the shims to adjust the backlash are in picture 4)

The other shim that needs to be checked is on the other side of the crown wheel, I found fitting a smaller shim with some plastigauge laid on the surface worked well to find the nearest shim size. The pain in the ass bit is reassembling the diff each time to check the contact patch or backlash.

I haven't taken a picture of the last shim but it fit's on the ledge at the bottom of the machined section in the
5 picture.

The other adjustment you'll need to do is the support peg in picture 6 which is done with a feeler gauge after you set the backlash, it's the adjuster on the outside of the face plate

[Bobbed06]

Now you know its done right, and the noises it makes are correct. Post up the part numbers you ordered and used. Dont forget the part# for the upgraded bearing!

I am sure experimenting with various gear lubes will result in further reduction of gear whine. It will need to wear back in some, now that the mesh has been changed. So expect it to get quieter with miles.

[davidpaul]

Odd how I was convinced she was too tight, a degrease and dial gauge proved me wrong

[NMKawierider]

Odd how I was convinced she was too tight, a degrease and dial gauge proved me wrong

May have been how it was meshing made you feel it was tight.

[davidpaul]

The bearings are standard size's so should be able to purchase at your local bearing store, the two bearings on the crown wheel are -
55x67x20mm (roller bearing) and the large one is -  Deep Groove Ball Bearing 85x130x14mm

I don't know the size of the pinion bearing but the number should be stamped on the edge.

I got the shims here-

http://www.alpha-sports.com/cfmoto_parts.htm

[Bobbed06]

Any more miles logged since the diff setup??

[Revolutionary]

Excellent post & thread, David. Wish I knew how to do stuff like this, I wouldn't trust me within a thousand feet of a disassembled differential...