Failed XS750 Final Drive (Images and video link)

[cywelchjr]

I see this issue as the major problem with this swap if you disturb the pinion nut. I personally think that the best course of action would be to check the FD 'externally' as per the service manual (not the FD manual), and if it's within spec, then check to see what the actual preload is. Record and use this number when re-tightening the pinion nut, not the number in the FD manual. I'd also be very hesitant to change any other clearances on a 'worn-in' gear set that externally checks good, as you're changing the wear pattern and IMO that can only promote more/faster wear....

Just my .02.....

I suppose somebody will come along and say they've done this swap using a rock and a stick for tools and haven't had any problems, but the fact remains that the factory gives very specific instructions for setting these up; I doubt if it was just to entertain us...

Unfortunately, until someone figured out to use nails to plug the lube holes you HAD to disturb the pinion nut. Knowing from my auto shop days and some reasonable experience as a shadetree mechanic over the years pretty much what you said, and not having anything to measure the preload, I did it by feel, and then put it back to the same feel. So far it seems to be fine, but time will of course tell .

Oh, and I and I didn't use a rock and a stick, it's was TWO rocks and THREE sticks .

[XJOK2PLAY]

Hi Scott...
Long time no talkto...
Sorry to hear you're having so much FD trouble.

Just wanted to add...
Cody was the first to point out there are differences between the 750 & 850 FD's... several years ago when he still had Zilla and was doing the swap himself. He first installed a 750 FD, took the pinion nut and all that apart... and 2000 miles later it locked up... at speed... and he came to a screeching, skidding halt! (A quick underwear change was then mandatory... so he said...)

It was the next drive he got... an 850... where he saw the differences, and that you don't have to disturb the pinion nut on one, and documented how to plug the holes.

So... when I decided to do the swap 2 years ago on my Maxim, I chose an 850...

Happy to report after 31,000 miles... -0- problems. Changed oil not too long ago, clean as a whistle, still get 2 extra mpg's, and enjoy the reduced rpm's on the freeways. (Knock on wood....)

I don't ride like a guy with his hair on fire (all the time, that is...) but I don't grandma it either. I ride 2-up a lot, and if you guys recall, it's got the full Vetter touring setup. Usually pretty loaded for long trips.

Last trip I took... Tulsa, Ok. to Branson, Mo. For those who've never ridden in Branson on a bike... well, let's just say... after I got there, I was missing my stock 11 FD! LOTS of hills... LOTS of traffic, all stop & go... plus riding 2-up.

Thus far, the only little problem I've noticed has been my clutch... and I've got the cure for that purchased already... new springs.

Occaisionally, when I'm getting on it, it'll slip a bit... usually WOT in 4th gear... Can't imagine why...?

But, I totally agree with what you're saying... the life of a 750 FD depends on how easy ya ride it. I believe the 850 to be the better choice, and it's an easier swap, to boot.

Still happy to report mine's still rolling fine!

Hope ya get ya a good 850 FD soon, and I think you're problems will be behind you then.

Oh, and Greg's correct... we all know Tod, and his ability to break every bolt on an 11... I've witnessed it firsthand... that's why he knows so much about an 11! Trial & error... lots of error...
Best of luck to ya, Scott. Good write up, too.

[3Phase]

Still Alive!

Whew! I just got back from a two day blast down and back to see GarthXS in Sandy Eggo with the trusty XJ1100 final drive on my bike. I got a panic-stricken voice mail message on my mobile phone when I stopped for gas on the way back home this morning because a young wanna-be squidlet lost it on Hwy 33 yesterday and went head on into an unidentified 50-something rider from Simi Valley, killing both of them and injuring three other riders. My family had been calling hospitals, police and mortuaries all morning while I was out on the road with the mobile phone tucked away in the fairing.


There was no drama for me on Sunday but the gas mileage on the way down and for the first half of our ride was around 32 MPG. Once we stopped for burgers and I checked the tire pressure I suddenly remembered that I'd let half of the air out of the tires to go canyon carving. I put them back up to 42 front/44 rear and gas mileage went back up to a more normal 36 MPG on the highway.


On the XS850 final drive the large ball bearing failed. I could hear and feel it when I pulled the drive off the bike. What I should have done instead of messing around was just buy another final drive. A shiny new bearing would have cost less than what I paid for that ate up final drive but the gears were hammered and I didn't believe it was worth spending any more money. As it turned out I don't need to get my believer fixed, it's working just fine.

I did even touch the large nut on the pinion shaft and pinion bearing preload was a few fine frog hairs on the loose side but still good. I washed everything with CLEAN diesel several times to get the sludge out and let it all drain for a couple of days, then took a peek at the pinion gear and the inner pinion bearing and race with a mirror and a magnifying glass. The bearing and race looked "okay" and the input coupler turned smoothly by hand with no crunching or slop so I let those sleeping dogs lie and screwed up the ball bearing on the ring gear instead of the pinion bearings.

Before I buttoned the side cover back down I hand-filled the pinion assembly and the ring gear needle bearings with 85W-140 gear oil while turning the input coupler by hand until no more air bubbles came out so nothing would be dry, then I put on the side cover and finished filling the drive with oil. Oh, well, better luck next time!

I did try putting an XS1100 final drive side cover casting on the XS850 final drive ring gear bearing and housing but it didn't fit all the way down. Even without any bearing shims at all it was still maybe 2mm shy of touching the final drive housing and would have distorted or broken something if the nuts were tightened.

It may be possible to cut the bearing recess a little deeper in an XS11 side cover casting so that I can use the heavier XS11 bearing and side cover on a XS850 final drive but that little project will have to wait until I find an unopened stack of freshly-minted 'tuits after winning the lottery because XS850 final drives are still cheap. I'll just find another '850 drive and try again!


A quick price check today for the final drive bearing:

The '750/'850 drives have a ~$25.00 16014 bearing 110mm x 70mm x 13mm.

The XS1100 has a ~$66 16014C2 110mm x 70mm x 17mm.

That's $10.25 per millimeter for the extra 4mm on the C2 XS1100 bearing.

[natemoen]

Alright, so I have my new FD pulled apart, what do you suggest looking at?

[3Phase]

Alright, so I have my new FD pulled apart, what do you suggest looking at?

Nate, take a look at the pictures in the first post in this thread. You can download a larger copy by clicking on any of the images. They show what good and bad gears look like along with the surface of the needle bearing race on the ring gear shaft.


Before you do anything except look at the gears, get some clean solvent and wash the heavy gear oil out of the final drive housing, the gears and the pinion assembly while looking for metal chunks and sparkly bits.


Do not spin any bearing when it is dry. A quick shot of almost any light oil will lubricate the bearing(s) enough to be able to hear and feel any defective bearing(s) without damaging any good bearing(s).

To check the carrier bearing on the ring gear, do not! remove the ring gear and bearing from the side cover casting. Hold the side cover casting in your hand and spin the ring gear. If there is anything wrong with the bearing you'll be able to feel it and hear it.


Check the pinion bearings the same way you checked the carrier bearing but leave the pinion assembly in the final drive housing. Hold the final drive housing in one hand while you spin the input coupler with the other hand and you'll be able to hear and feel any problems with the pinion bearings.


If the gears and bearings are okay, use an oil-free solvent to clean the oil holes in the input coupler, then glue a couple of plugs into the oil holes. Let the glue set up before you try to do anything else to the final drive.



After the plugs are glued in place and the glue is completely dry/cured/set/whatever, wash the light oil out of the bearings before you put the final drive back together. Let everything drain into a pan for about a half hour and make sure there is no solvent left on or in the parts.

Slowly fill the needle bearing in the final drive housing and the pinion assembly with gear oil while you turn the input coupler by hand until you can see no air bubbles in the oil.

Carefully put the side cover and ring gear back on the final drive housing and tap it into place with your hand or a rawhide/rubber mallet.

Using a star pattern, make three passes to bring the final torque on the side cover casting nuts to 16 ft-lbs (2.2 m-kg).

Finish filling the final drive with oil and turn the input coupler a few times to get everything inside the drive coated with fresh oil.

Set the drive vent-side-up somewhere out of the way while you finish making a spacer and installing the drive shaft in the u-joint yoke.

[3Phase]

XS1100 and XJ1100 Final Drives

I remembered to check the XJ1100 final drive part and casting numbers while Roo and I were changing out the bad XS850 final drive and putting the XJ1100 final drive back on Columbo.

The XJ11 drive that I have uses the same part and casting numbers as the XS11 and the outer side of the pumpkin is painted black.

XS1100 and XJ1100 Type II final drive casting numbers.

Housing: 2H700
Side Cover: 2H700 and Y1 (cast but not in picture)

[latexeses]

You're going to have to sew a big thick patch of leather on top of your left boot now. Trying to find that last gear

[3Phase]

You're going to have to sew a big thick patch of leather on top of your left boot now. Trying to find that last gear

I have to change the shifter seal, too. It's starting to weep and mist a little around the lever but not enough to drip or get on my leathers and boots.

"Just one more thing...."

[motoman]

Good that it's just........one more thing.....

[3Phase]

Try, try, again!

I got a package in the mail this afternoon; 1980 XS850 Midnight Special final drive that looks like it's in pretty good shape!

The JB Weld holding the aluminum nails in the oil holes in input coupler has to set up overnight so it should be installed and running by tomorrow afternoon.



XS850 Midnight Special final drive looks really nice with the gold accent





XS850 Midnight Special final drive housing and pinion gear with a good contact pattern





XS850 Midnight Special final drive with a good ring gear contact pattern




Dark Star Orchestra
25 September 2011
Ventura Majestic Theater
Ventura, CA

Song: Playing In The Band

Show Performed: gd73-22-02
Assembly Hall, U. of Il
Champaign-Urbana, IL




Oops! How'd they get in there?

[CaptonZap]

Whilst surfin the web, I came across this;

<http://www.xadoshop.com/page/page/6634506.htm>

Not being one to believe in snake oil, I didn't run out and buy some.
But, by golly, I may just try some in the 850 FD and MD. Temperatures should be reduced, and if they aren't, I can drain the drives and go back to GL5.
Unless, of course, someone else beats me to it. Hint, hint.

CZ

[natemoen]

Whilst surfin the web, I came across this;

<http://www.xadoshop.com/page/page/6634506.htm>

Not being one to believe in snake oil, I didn't run out and buy some.
But, by golly, I may just try some in the 850 FD and MD. Temperatures should be reduced, and if they aren't, I can drain the drives and go back to GL5.
Unless, of course, someone else beats me to it. Hint, hint.

CZ

WTF is it? It doesn't even say what it is on the website.

But it can perform an engine rebuild!

[BA80]

WTF is it? It doesn't even say what it is on the website.

But it can perform an engine rebuild!

In a can..................Engine restore....why not Final drive restore.

It all = magic

[CaptonZap]

WTF is it? It doesn't even say what it is on the website.

But it can perform an engine rebuild!

Aww, Nate. You just have to look around on that site, and they tell you how it was discovered. By the Russkie oil well drillers. CZ

[CaptonZap]

Addendum

For law enforcement types that are reading challenged,

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


This has some pictures.