Final drive woes / parts needed

[Jerry]

Came down an off-ramp, stopped, let out the clutch and nothing but a grinding sound. Hooked a ride home, went back and trailered the bike back to the garage. Pulled the final drive (differential) and found the driveshaft splines and splines in the differential both worn to the point where the driveshaft was - literally - spinning inside the diff.

Anyone have a good used diff / driveshaft they would part with? I see a couple on eBay, will bid there if necessary.

I had lubbed this a couple times in the last few years, suspect early neglect and my pulling a trailer both contributed to the wear and subsequent failure. So, just a reminder...when you pull the rear wheel, take time to remove the 4 bolts and pull the diff as well. Pull the drive shaft and lube both it and the inside of the diff....or you may end up stranded at the bottom of an off-ramp!

[TopCatGr58]

Hey Jerry,

I don't but several members should have a spare OEM final drive since they have done the XS750 final drive swap! Maximan is near you. I think Tod/TRBIG has also done this! Perhaps they will be willing to part with their OEM final drives!?
T.C.

[mason79]

ebay.... the great equalizer

[trbig]

Now sounds like a good time for the 750/850 drive!

If you are going back stock, I have one I could part with.... I just don't know if it's here or at John and Kat's house still?? I'll never go back to stock anyway.

This is honestly the first one I have heard of going bad.

Let me know.


Tod

[John]

Tod

You old FD is still here in my shed.

[trbig]

I was wondering about that.

So Jerry....

Play nice with John and see if he'll send it to you and how much to ship it... and when he can. I've got a spare here but it's still on the parts bike.

Tod

[Jerry]

Thanks.

Have considered gong to the 850 drive, but since most of my riding is between 5,000 and 6,000 feet, and I pull the trailer on almost all of my long trips, the higer numerically final drive still holds some appeal. Many of the passes I ride are between 8K and 11K, power fades even more at those elevations, so I'm thinking the stock FD may be the best way for me to go.

So John, could I impose on you to box and ship me Trbig's final drive? Will pay shipping and any reasonable price, paypal, money order, however you like to get $$.

Also need a drive shaft. While mine may work in a new FD, there is a wear pattern on the teeth that doesn't look healthy. Any chance you have one of those floating around?

I'll try to get some close-up shots of both the shaft and the FD splines. There appears to be about an inch or so in the middle of the FD splines that is badly worn.

[trbig]

This type of argument against the other final drives is something that just isn't getting through I guess. You have no less power, you're simply turning less RPM's at top gear at a certain speed versus the stock. For the few times you are going to the higher elevations, 4th gear is almost identical to 5th in gearing with the mod... so just downshift one if you need more rpms.

Whether you're at 4k rpm or 4700 at 70... you are still in your power range. I don't understand the argument... but it's your bike and your decision.

I had to use the driveshaft from mine since the 750 one I used is much smaller. Any 1100 final drives from any year will work... as well as the driveshaft. So if John doesn't have one, anyone should be able to help.

Tod

[Jerry]

Trbig:

The OEM gear ratio is not so much for cruising as it is for starting from a dead stop. With me at about 265 and another 180 pounds of trailer and gear, getting started from stoplights and corners can be an issue. The higher gear ratio of the stock diff would let me get started at higer RPMs, giving me a bit more accleration in the lower part of the rpm range. We are talking 1st - 2nd gear here, by the time I'm in 3rd I'm moving pretty well along. The stock ratio would give me better performance in this scenario.

Most of my pass riding is also sight-seeing; I take a lot of photos, particularly in the fall when the colors are changing. This involves a lot of stop-and-go. You loose HP with elevation; at 10K you are down around 15 percent or so. Since my XJ isn't the strongest engine around I often have to slip the clutch to get moving from the shoulder. Going with the lower-geared (2.9 vs 3.3) FD would mean more clutch slipping and lugging at low RPM.

I agree, would like to do the 850 FD mod for long trips, and will probably do so before next year's rally season starts, but for now I just want to get in a few more weeks of riding before winter.

[rover]

Jerry, I have the parts you need, XS1100 final drive and driveshaft. It is the only spare shaft I have for the 11, but I guess I won't need it. It is yours for shipping cost. PM me and let me know.

[JACKHAMMER01]

Last year, the final drive on my 81 went out (locked up) at 70mph. I found one from Roger, at the link below. he charged me $30, plus shipping. If all else fails, give him a call.

http://www.motorcycle-recycle-center.com/

[JWSanders]

Originally posted by JACKHAMMER01
Last year, the final drive on my 81 went out (locked up) at 70mph. I found one from Roger, at the link below. he charged me $30, plus shipping. If all else fails, give him a call.

http://www.motorcycle-recycle-center.com/

I could spend hours going through that place! What a great resource for old bikes! Thanks for the link.

[Jerry]

Thanks, guys, for the offers and contact info. At this point John is going to see if he can find Trbig's old unit and possibly a spare drive shaft and ship those out to me. I greatly appreciate his and Trbig's help! If I need anything else I'll follow up with another post.

Jerry

[JACKHAMMER01]

Since my shop specializes in the older metric bikes, I have dealt with Roger on many many occasions. Actually my wife usually deals with him. He and I are both considered grumpy old men, but my wife can get him to almost smile. He is a great resource for us, and only once did he not have the part I needed.

[Jerry]

First of all, thanks for all the help, patrticularly John and Trbig. I installed the replacement final drive last night and rode to work this morning, everything seems to be working fine!

A couple comments on the install. First, I had to peel back the U-joint boot and use a small screwdriver to lift up the wheel-side of the U-joint in order to get the drive shaft in place. Had a bit of a time getting the boot spring re-hooked, finally put a small piece of wire in each end and pulled the ends together, got them hooked, then removed the thin wire. Easier to do this on the XJ with the side cover removed.

Other than the boot spring it was just a bolt-in swap. I used wheel bearing grease this time to pack the differential splines, also put some on the U-joint end of the drive shaft. I topped off the FD with Rotella 80 - 90 wt. gear lube.

I plan to take a few photos of the old shaft this weekend and show it as a comparison to the replacment; you may not belive the difference in profile on the splines!

Again, thanks to all who helped and contributed to this thread.