Final Drive Question

[conquest87tsi]

I have a XS750 final drive that unfortunetly has a cracked casing near the drain plug. Would it be possible to swap the ring and pinion gear into an XS11 case? I haven't really read anything about swapping the internals. Also what is the torque on the pinion nut supposed to be?

[mack]

Probably cheaper

and less hassle to just score one from one of the members or flea bay.

[conquest87tsi]

Well Mack,
You see I did get a 750 FD from a member. A very clean one in awesome shape and assumed lowish miles. Unfortunetly the case was damaged.

I did do some more searching and it looks like the 750 gears are not going into an 1100XS11 housing.

So onto my next question. I purchased another XS750 final drive, however the quality of this one is far far worse. I was thinking of disassembling the two and if the gears of the one with the damaged case are better, just swapping them into the ugly, scratched, and corroded case of the one I recently purchased. After sanding and repainting of course.
What precautions do I need to make when doing this? I have read about bearing preload, how is this checked?

[crazy steve]

Setting one of those up is a ticklish job..... Swapping cases/gears will mean you'll probably have to do the set-up from scratch. Look here: http://www.ringler.us/xs1100/ShaftDriveManual.pdf

[conquest87tsi]

Thanks a lot Steve!

[crazy steve]

To tell the truth, you'll be better off just getting another final drive. These were hand-assembled by Yamaha and they had all the special tools/jigs to do this. Much harder to do after the fact....

[crazy steve]

I'll add that if it's only cosmetics that's the problem, you can pull the ring and pinion gears out and then reinstall them as long as you make sure you get everything back the same. One thing I'm not sure of is if the 750 drive uses a 'hunting' or 'non-hunting' gear set. Makes a big difference, as a 'non-hunting' set will have a different wear pattern and will quickly fail if the gear teeth aren't matched back up exactly...

[Erik the Red]

Yeah, what Steve said.

I rebuilt my FD under the tutelage of a local mechanic a couple years ago. According to him, everything has to be put back EXACTLY as it was before you touched it, b/c as steve said, these were essentially individually handmade units.

To be exact, I counted turns of screws. Shims have to be kept in the same order, and go back in the same orientation. You have to mark which tooth meshes where it came from and be sure you put it back that way. Not incredibly difficult, but for me it was incredibly time consuming, because I was as precise as I could be. If you do choose to do this, replace the gaskets that you can easily get to (I think like 3 out of 4 are easy enough, or something like that), so that you won't get a leak in a year and have to do it again.

This is a fix where close enough is definitely NOT close enough. It's definitely easier to just get a whole new unit.

[motoman]

+1 what Steve and Eric stated. Unless your already an expert at setting up ring/pinion assemblies in the automotive world with a dial indicator and "reading" correct backlash patterns and other measurements, another drive IS your best option.