Failed XS750 Final Drive (Images and video link)

[BA80]

When are you gonna learn how to post a link CZ?

http://www.xadoshop.com/scienceofxado.html

[motoman]

Looks like some serious snake oil in a can...........

[natemoen]

Looks like some serious snake oil in a can...........

That it is! It is able to recreate metal surfaces for nothing!

[3Phase]

That it is! It is able to recreate metal surfaces for nothing!

Hmm, I'll have to read up on that stuff, I may need some extra metal in a can.

I just got back from a test ride after finishing up the '850 final drive and I suddenly remembered what was bothering me right before I left: I forgot to finish tightening the final drive nuts to the swingarm!


Oh well, I'll fix that after the bike cools down but the '850 drive runs cool and smooth like buttah!

[CaptonZap]

When are you gonna learn how to post a link CZ?

http://www.xadoshop.com/scienceofxado.html

Howdy Greg, I figure that on a forum that is devoted to preserving the old bikes, I would be right at home preserving the old way of posting links. CZ

[CaptonZap]

Hmm, I'll have to read up on that stuff, I may need some extra metal in a can.

Yep Scott, you were who I thought of first. But then I figured that some of the other anal orifices might get irritated by the suggestion that anything in a can might actually work, and it might be entertaining to see what sort of response it would draw.
Anyway, in the interest of scientific investigation, I rode my scooter over to the local dealer, who had a tube of the gearbox treatment. Unfortunately, I am waiting for a rebuild kit for the rear master cylinder, so it will be next week before I can take a run up the 5 mile 7% grade west of town to get a "before" reading on the temps of both drives. The instructions say that it may take up to 50 hours run time to achieve maximum effect, so that will take some time, and then I will have to wait for a day with the same ambient temperature, (Want to minimize the variables, dont'cha know), run it again and get an "after" temp reading.
The package says that the 9ml tube treats 1-2 liters of oil, so with the final drive using about a third of a liter, and the middle drive a little bit more, lets figure that a tube would treat three bikes, and that works out to about twelve bucks a bike. Which, if it works, is a lot cheaper than buying final drives all the time, and if it doesn't, I've spent more than that on beer on a Sunday afternoon, with about the same benefit. (Although, the compost heap does like the processed beer )
If you get some and test it before I do, let me know, and if you don't, I'll PM you with my results. (We'll leave the plebeian masses in the dark until the fun is done)

CZ

[3Phase]

Trick or Treat!

Cap'n, they mention 900 C to 1200 C flash temperatures at the microscopic peaks of the base metal for the bond and creation of a self-renewing cermet composed of their patented particles and the wear metals in the oil.

The pictures on the web site show a progression from a well-worn and thoroughly baked bearing race as it is restored to a shiny, newly-machined, finish across the full width of the race even where the bearings couldn't possibly have touched it. Normally that could never happen with any oil or additives but I think I've figured out how they did it:


Patented Particles:


Carrier oil:


Pay no attention to that reptile behind the curtain....

[CaptonZap]

LOL,
To late now, I bought some. Hope the compost heap doesn't dry out before I can get back to the beer.
CZ

[Lbrown311]

Do I need another reason to not wanna do the mod...or will this suffice? Thats why people hire engineers to develope ratings and material thickness on things like this. I bought this bike to ride this bike...not to modify it to a 750. Thats why they were two different bikes. Been awhile since I've been on and I've been outa state but I rode the piss outa Black Mamba this past weekend while I was at home. Wish they made the transmission better tho. 2nd gear is annoying.

[cywelchjr]

Do I need another reason to not wanna do the mod...or will this suffice? Thats why people hire engineers to develope ratings and material thickness on things like this. I bought this bike to ride this bike...not to modify it to a 750. Thats why they were two different bikes. Been awhile since I've been on and I've been outa state but I rode the piss outa Black Mamba this past weekend while I was at home. Wish they made the transmission better tho. 2nd gear is annoying.

They did, they came out with replacement backcut gears that don't get the problem. They are factory versions of the second gear fix. I don't know if my current engine had the fix done or had replacement gears put in, but that sucker pulls the gears into place, never a missed shift (ok, I get a false neutral once in a while but that is all) with it. It looks like the 850 FD's may do pretty well, and that will probably be what I'll put on next, assuming that I don't have the tougher version of the 750 FD that we think is the same thing (next time I have the rear wheel off, I'm gonna check and then I'll know for sure, cause I know what to look for now). I'm just about to the first oil change interval on mine, so I'll be looking real carefully at how it looks coming out, but it's still running nice and cool, and still running really smooth, but by reports so did Scott's until right before it failed, so that doesn't really tell me much. Lets just put it this way, if 1st gear feels almost completely worthless to you, and your always looking for 6th gear, then the mod MIGHT be for you, and I DO mean MIGHT. I like the mod, and couldn't really see going back. Frankly, if I had to put another drive on every 6,000 miles, it would be worth it to me. I'd just pick up drives far enough in advance to be able to pop one off and pop the next one on instead of changing the oil . But I think it's gonna last a good bit longer than that, and prepping one is frankly pretty easy, the hardest part is getting the drive shaft ready, and then getting it back into the yoke, and once that's done, it's over, Scott's job while beautiful and all, is IMHO overkill, far more than is needed to last the life of the bike, as a simple copper spacer will do the job just fine.

[3Phase]

Lbrown311, you don't need any reason what so ever one way or the other to keep the stock final drive on your XS, just ride it and have fun!


Cy, after 40,000 miles with the '750 drive the u-joint bearings and the drive shaft splines were still in great shape but the nodular cast iron splines in the yoke were just beginning to show a little wear and more slop/wobble than when I measured it back when I first put on the '750 drive.

The metal pins I used the first time around to hold the splined spacer on the end of the yoke did keep the yoke/spacer/drive shaft sandwich stable but the pins were beginning to enlarge their holes and they were no longer a tight fit. Basically, the splined spacer was doing its job of holding the drive shaft in position like a copper or bronze spacer but its splines were not doing doodley.

Liberating a yoke from one of the other bikes was too much like work so I just cleaned everything with solvent to remove every speck of moly grease, then I put the spacer back on the yoke with the pins in place and seated the drive shaft to hold it all in line so the welder could run the MIG around it.

The 'new' yoke is straight with no slop or wobble and the drive shaft splines are engaged for their full length except for a small gap in the splines where the spacer and yoke were welded together. I greased the yoke and drive shaft splines with moly 60 paste and I also filled the weld gap with some more moly60 paste so I shouldn't have to worry about greasing the yoke/drive shaft for a very long time.