750 FD swap - Torque and no turn

[petejw]

I havent done the final drive swap but,
wouldnt it be possible to just mark the nut to the housing
before removal, then tighten the nut back up to the marking?

[John]

That would work only if you use the flat washer from the 11's FD in the 750 FD, otherwise the thickness of the washer used may vary from the washer used in the 11's FD. The 11's washer is the correct diameter to block the oil holes in the 750 FD, but I don't know if they are the same thickness as the washer in the 750 FD.

[Ivan]

Pete, I would be wary of using a marking like that, since things usually don't seat the same way every time. Like John said you would have to have the same washer, but you also need to turn the pinion a few times after torquing it and check it again. It may be a good indicator of being in the ball park, but I wouldn't trust it.

The good news is that inch pound torque wrenches can be had for just a few dollars for the low end bar type, which will be accurate enough to get the job done. Seems like the local parts house had a beam type 1/4 inch drive calibrated in inch-pounds for $20.

[DGXSER]

Thanks for all the great input!! I took a week off to go to Boy Scout camp with my son so the bike is sitting in the garage with the drive shaft out and the FD still where it was.

The crush sleeve now makes ALOT of sense out of the torque issue. So the NEW sleeve needs the 75-105 ft lbs of torque to CRUSH it down to get the pinion gear lash set appropriately. Having NOT removed the pinion at all, I do not need that kind of torque. This has been my problem with figuring this out and feeling comfortable with not torquing the nut.

I tried Sears and HF for inch pound torque wrench and none had it? Being a 79, sounds like mine should be 10-15 inch pounds.

[3Phase]

I tried Sears and HF for inch pound torque wrench and none had it? Being a 79, sounds like mine should be 10-15 inch pounds.

Don, you'll have to look and see what Type of gear set it is before you dive into it too far. The inexpensive inch pound torque wrenches I've seen don't go down far enough to use on the mid and final drive gear sets. You can't use a "click-type" torque wrench to measure bearing preload, you need a small beam-type wrench calibrated in inch pounds or an experienced elbow. The exact torque required will depend on if you are checking a Type I or Type II gear set and whether you're re-using the old parts.

Stock XS1100s use Type II mid and final drive gear sets. The 750 and 850 may use Type I or Type II gear sets.

Type I final drive bearing preload: 9 - 10 in lbs @ 54 - 61 ft lbs torque

Type II final drive bearing preload: 3.4 - 4.3 in lbs @ 72 - 108 ft lbs torque


Type I uses shims and spacers to set both the input pinion depth and input bearing preload. Add or remove shims and spacers to achieve the correct depth and bearing preload in the specified torque range.

Type II uses shims to set the pinion depth and a crush washer to set the bearing preload. Add shims to set the input pinion shaft depth and torque the large input shaft nut until you reach the correct bearing preload, then stop. It will be somewhere between 70 and 110 pounds of torque if you use a new crush washer.

If you are re-using a crush-washer: use Locktite on the nut and go by the bearing preload value in inch pounds, not the final torque value on the nut in foot pounds.

Do not over-torque the nut. You will ruin the crush washer and you will have to start over with a new one or ruin the input shaft bearings. The crush washer is still available from Yamaha. I got one for ~ $15 last year when I put a 750 final drive on my bike. I've had no mechanical problems at all with the final drive.


Regards,

Scott

[DGXSER]

I found the 750 FD manual and read through it to determine that since mine has the phillips head screw in the hole it is a type II. Being a type II it would only be around 4 inch pounds.

That is so small, I think I could blow on the end of my torque wrench and cause that much torque. So I removed the nut, coated it good with red locktite and tightened until it just started to cause friction or difficulty in turning the drive. Then backed it off and re-tightend to just before that.

The drive shaft is not to bad to install once you slide the rubber boot back and control that joint. I skipped the second o-ring, I figure the drive shaft, the coupling and the copper bushing will turn in unison, so no real wear could occur.

One hint for those doing this project, remember that spring on the end of the drive before you get the tire mounted and ready for brake reinstall, it sucks tearing that all back out for a spring!

Now for the ride report.....WOWWW It really is the bomb schnizzle sheitz. 50 MPH at about 3k. I totally agree that 4th gear is much more than a passing blink on the way to fifth now!! And I can sense no lack of get up and get out of the way!!! Well worth the effort!

Thanks again for all the input and advice!

[3Phase]

Thanks again for all the input and advice!

Amazing, isn't it.


Regards,

Scott