FD swap copper spacer

[dbeardslee]

Thinking more about this today, I have had this same driveline and collar on the bike since I first put the first final drive on and several engines ago. So it's safe to say I've got well over 200k miles on it with no noticeable wear... Yet.

200K miles!!! I thought you had to reincarnate to put that many miles on a motorcycle! I think I'll stop worrying about spline engagement now.

[BA80]

200K miles!!! I thought you had to reincarnate to put that many miles on a motorcycle! I think I'll stop worrying about spline engagement now.

Not Tod, his wife actually married the XJ, he just came along with it and she has been riding him for years since.

He does need to rethink his lubrication practices though. His spline engagement failure was due to improper lubrication. Fatal mistake.

[motoman]

I love real-word information. When does the real world information get here?
"It ain't broke yet an' I ain't dead yet neither!" would make a good reality T.V. show but that's about it.

Greg, I've never used a laser measuring tool either, just calipers and micrometers. Okay, modified driveline parts that should not be worn out really aren't worn out even after 50,000 miles. Bravo! Nice pictures! Meanwhile you've beaten all but the last 7mm of stuffing out of your own straw men and chased your own red herrings completely out of your own net while totally missing Maximan's years-old arithmetic error. O-o-okayfine, put your boots back on now, man!

Tod, I don't feel slighted in the least, it's not my bike and it's not my parts but the arithmetic problem is funny. I have never said that real-world experience doesn't mean anything. The hub on your XJ has nothing to do with Greg's spacer and driveshaft but I used it as one example of yet-another non-contact driveline part that can look great on the surface and can actually be in pristine condition but mask a problem like splines that are about to break off.

What I would be interested in hearing about is your real-world experience with the engine Main and Rod bearings. After I get the cases painted I'll be putting the engine back together with its third crankshaft. The second crankshaft worked for ~90,000 miles but this time I'm trying to use used bearings and I could use your advice! No stupid smilie, no BS, I could use your advice because you're the only one I know that's even tried to do this in the real world and eventually succeeded. I'd like to try and avoid that whole 'eventually' part of the build.

.

Hey Scott, these are stories/fibs we normally pass around the campfire after riding hours

[dbeardslee]

Not Tod, his wife actually married the XJ, he just came along with it and she has been riding him for years since.

He does need to rethink his lubrication practices though. His spline engagement failure was due to improper lubrication. Fatal mistake.

Now I'm confused - was the spline engagement failure a mechanical problem... or was it marital.

[BA80]

Now I'm confused - was the spline engagement failure a mechanical problem... or was it marital.

Ha ha ha........I had a beer or 10 before I wrote that Doug. Didn't come out exactly as it sounded in my fuzzy head at the time.

To be clear, the spline drive on the wheel that fits into the FD stripped out due to lack of lubrication.

The cause for the failure of more than one romantic relationship as well.

[TopCatGr58]

200K miles!!! I thought you had to reincarnate to put that many miles on a motorcycle! I think I'll stop worrying about spline engagement now.

Hey DB,

I'm not trying to stir this pot, but with the several engine changes, this MOD got several NEW or unused via modded U-joints. I can see what Scott is talking about in concern for the splines inside the U-joint itself. The Driveshaft appears unmolested....but I think folks have stated and agreed that the driveshaft is of a stronger metal than the U-joint female splined section.

I haven't looked at an OEM driveshaft and U-joint when they are properly MARRIED....I understand that the slot 7mm's from the end of the driveshaft has the Compression Ring in it, and that it ends up going beyond the splined section of the U-joint when engaged...but I don't know IF the shoulder of the Driveshaft is up against the end of the U-joint...or if actually might do a little sliding in/out with the up/down motion of the swingarm....or if that in/out action occurs at the Final Drive junction instead??

Using the previously posted images...there is an alleged 24.7 mm's of spline engagement of the shaft to U-joint once it's inserted in the OEM configuration. But this measurement is also possibly flawed...this amount assumes that the entire length of the driveshaft splines are mating with U-joint splines. But as was shown...the U-joint has some 7mm worth of taper/recess in the end of the joint....so the question is also how long/deep are the splines INSIDE The U-joint section. They may actually be LESS than the 24.7 mm's of remaining OEM splines of the driveshaft after/behind the Ring clip.

The question seems to me is how much length of U-joint spline engagement is needed to maintain stable alignment of the U-joint on the Driveshaft end/splines...lest it allows the U-joint section to wobble a little bit on the end of the driveshaft which could then lead to excessive wear of the splines and possibly eventual failure?? With the OEM position of the driveshaft end protruding thru the entire length of the U-joint splined section, there's no room for the U-joint section to then WOBBLE around to wear. But with the MOD...the end of the driveshaft is engaging just the END of the U-joint splined section....and how far into it.....is far enough to prevent it from wobbling? And with several engine changes....and I would assume U-joint changes....the U-joint splines have been getting refreshed with every change. The driveshaft hasn't, but again we assume that it's of a harder material and so will not show much/any wear compared to the possible wear that might be visible/measureable in the U-joint splined sections of the engine.

Perhaps the amount of spline engagement IS adequate with this MOD, and not wear via wollowing of the U-joint end will occur...but this examination is what I think Scott is talking about to help confirm that indeed the amount of spline engagement is enough to not allow any wollowing/wearing of the U-joint splines???

That's my view of this debate....hopefully everyone will CHILL a bit and see where everyone is coming from in their concern or lack of concern regarding the durability of this MOD.

We have seen spline failures both in the Final Drive to driveshaft splines as well as Driveshaft/U-joint splines on OEM systems when Lubrication was absent! SO...saying that U-joint Spline failure with this MOD isn't possible IMHO isn't prudent....and possibly not totally proven YET....until a view of the U-joint splines is performed so show that there ISN'T ANY measurable wear shown/seen on the U-joint spline section.

T.C.

[dbeardslee]

I did read the thread on lengthening the u-joint splines using a donor u-joint for the added length. Might be overkill, but I kind of like that idea - if only I could weld. I do know a local shop that could handle it, though.

Maybe I'll do a little e-baying to see what u-joints are going for. If I can find a couple I might undertake that modification to the modification this winter when I'm searching for things bike related to do. I'm not sure it needs it, but it might be an interesting project. It's about due for some new 60% molybdenum paste anyway, and as long as I've got it apart...

And speaking of moly paste - this stuff has been working great for me, and it's got real high moly content -

[TopCatGr58]

I posted my last reply just while Scott was posting his findings to the 750/850 Mod thread....see his photos of his findings.

T.C.

[BA80]

When I swapped out the swing arm I went ahead and changed the drive line also.

Cleaned up the drive line I took out and got a close look at it. The u-joint end has no polishing or step wear I could see.



However, the FD end has heavy polishing and step wear.

[Bonz]

So, that means what in your estimation? The wear on the FD end would have occurred anyway? Or the wear on the FD end would not normally be there other than for the mod?

[BA80]

Just reporting what I found. That's the original DL with over 100K on it, 50K with the FD mod.

The rear of the DL will most likely wear like that as it does move in and out with rear suspension travel and it may not be exactly in line with the FD itself which would cause a slight wobble, for lack of a better word, as it spins in the FD collar.

The most significant thing here in line with this thread is that there is no polishing of the splines on the u-joint end. If there had been any wobble on the contact points of the splines, even though as has been said here that the shaft is harder metal than the yoke, it would have certainly polished the splines.

[Bonz]

Yes, thank you for the clarification. I thought that the u-joint splines were what you were making a point of, and the FD end is simply incidental wear that would happen regardless. Facts, you can use them to prove anything! Well done in this case.

Long live the copper spacer!

[jwhughes3]

OK lets all stop polishing our shafts and move along

Thanks for the update Greg. Now that we know your shaft has not been polished in over 50k miles we are all the wiser

At least your shaft is moving, mine has been dead since May. I am hoping to make progress next weekend as a buddy is coming over to help transplant.


John

[BA80]

I have a 3 day weekend coming up. Maybe I'll ride down there, drink YOUR beer and get the cops called to your garage at midnight.

[3Phase]

So, that means what in your estimation? The wear on the FD end would have occurred anyway? Or the wear on the FD end would not normally be there other than for the mod?

Whew! I finally get to read the thread today without the site 'sploding! Yay!

Bonz, the drive shaft wears with or without the mod', that's one of the things you should check when you grease the splines. IF the u-joint yoke splines wear and it starts to wobble it'll eventually thrash the drive shaft too. The original one in my '80G was ovaled at the drive coupler end from some kind of serious stress. The drive coupler and input shaft had flexed over and rubbed against the drive housing and the teeth on the drive shaft were wiped out. It all got replaced with a 'new' u-joint, yoke, shaft and a crotchety old '750 drive.

Tod, Greg, I think we've been saying the same thing but misunderstanding and talking past one another. Tod, thank you for clarifying the bearings on your engines; don't want to tie up Greg's spacer thread but it makes total sense! I'll have to shop around for some new Blue bearings. I already have three more good engines I can use that'll drop right in but this one has matching serial numbers so it has sentimental value.

The real world: Tod, I take the real world very seriously. Seriously: isn't there a local VA hospital in Oklahoma with disabled vets that you can try to BS? Or maybe just some local cardiac ward if you can't get in the VA.

I haven't felt good for the last couple of weeks. It hasn't affected my sense of humor one iota -- this whole thread is hilarious! but it has seriously affected my ability to organize my thoughts clearly and communicate. I have to go to the doctor today, I thought the cough was going away but it came back.

Now if the site posting engine will let me post....

.