final drive spacing

[danl]

Hi everybody,

 

Sorry if this posts twice, I tried to post last night on an old thread but I must have goofed something up because it hasn't shown up.

 

This is my first post, although I've been lurking around here for a while since I bought my '00 sport about a year ago.

 

My question is about final drive/needle bearing spacers. I think that I have a problem with the bearing spacing in the final drive, but not in the wheel. I have been reading all of the posts I can find on the topic, and I think i'm pretty up to date with all of your comments but I need some clarification.

 

I recently had a rear tire installed by my local shop (who was a BMW dealer when my '73 /5 was new, and a Guzzi dealer when the v11 was new but is now an independent shop) whom I believe to be very competent.

 

He pulled off the wheel and had another shop (with a tire machine) mount the tire. When he reinstalled the wheel and torqued the axle (with a torque wrench) he noticed that the wheel felt slightly notchy when spun by hand. This is about the point when I walked in the door planning to pick up the bike. I spun the wheel myself and agreed that it didn't feel right. I think a lot of lesser shops would not have even noticed the problem and sent me on my way.

 

I don't think the problem is in the wheel bearings, because he torqued them up with my axle and a spacer while off of the bike and they felt smooth.

 

There has been a lot of talk on the forum about a bearing spacer that may have been substandard from the factory. I think this refers to a spacer that is internal to the wheel, and defines the spacing between the wheel bearing inner races. I don't believe that this is my problem because of the test in the previous paragraph.

 

I think my problem is in the final drive. With the drive off of the bike I can see that the inner race of the needle bearing on the right does not protrude beyond the washer that surrounds it.

 

When the wheel torqued up with the washer, axle tension compresses the washer before the race and the wheel feels notchy.

 

If the wheel is torqued up without the washer (so the inner race is tensioned against the other inner races and spacers) the wheel feels fine.

 

he had another final drive on the bench, and it's needle bearing race stuck out farther than the washer.

 

My question is Has there been any concensus on the spacing of the final drive bearings (not the wheel bearings) and this particular issue? Can this be caused by improper wheel installation or other general knuckleheadery?

 

Was there a problem from the factory? It is possible that this problem has existed as long as I have had the bike since I had never had the wheel off the ground and felt it spin. Bike has 9k miles, 6k of which are mine. Gear oil looked perfect, and we even took the final drive apart to look at the gears- also perfect.

 

Rear tire had been changed once before I got it, and Ferracci had all of this apart to perform a gearbox recall as soon as I got the bike.

 

There is evidence that the axle was once tightened up with the washer overlapping the needle bearing inner race (could have driven this race into housing a bit) but this doesn't seem to be recent because the marks dont look very new.

 

I carefully rode home the 3 miles or so to my house and am awaiting a Pit Bull rearstand so that I can get these parts off and in my hands again.

[Guest ratchethack]

My question is Has there been any concensus on the spacing of the final drive bearings (not the wheel bearings) and this particular issue? Can this be caused by improper wheel installation or other general knuckleheadery?

Danl, you've described things very well. My compliments.

 

This here's a bit of a sticky wicket. A coupla thoughts.

 

It's been a common mistake to omit the flat washer between the final drive and swingarm. As I recall, this flat washer, which serves to keep water and road debris out of the final drive-float needle bearing, is properly clamped-up under the tension of spindle torque in "the stack", along with the needle bearing inner race -- this is consistent with your observation.

 

This is where things kinda get a little wacky on my end. If the above is the case, how could it've been that as you described it, the "axle was once tightened up with the washer overlapping the needle bearing inner race"?? Seems to me there's only one way it can go on?

 

My bike is a 2000, same as yours. You indicated that your shop Tech had another final drive on his bench where the needle bearing race protruded through the flat washer. This'd be a new one on me, and I reckon it's a different design than yours and mine.

 

My take here is that if the notchiness you feel is felt in the wheel, and if there is a bearing problem, your symptoms point to a wheel bearing problem, not a bearing in the final drive. Unless your shop Tech had everything in its proper sequence when he did the "test" torque of wheel with drive and all spacers and washer in place off the bike, there'd be little point in this exercise, and I have to wonder why he did it?? He must have used a spacer of some kind to substitute for the width of both legs of the swingarm. As to why the notchiness didn't show up when he did this, I can't imagine, but then, I can't imagine why it would've provided any value wotsoever to torque things up without the swingarm in the first place??

 

He must've had a reason to've done this, and it doesn't quite ring true.

 

It looks to me like you've got past consideration of the wheel bearing spacer. From your post, I would NOT be inclined to rule this out without further investigation. I'm sure you're fully mindful of this, but just in case, keep in mind that the problem with the stock wheel bearing spacers is that they will compress (on a permanent basis) under excessive spindle nut torque. If the wheel bearing spacer has compressed (by anyone doing previous work, for example), the symptoms of damaged wheel bearings may or may not be apparent even when full factory spec torque is applied to the spindle nut. The symptoms of bearing failure will show up later on the road, when wear from improper side loading takes a fatal toll on the bearings.

 

You probably have this covered, but just in case -- there's a spacer of approx. 20 mm in length (that is, lateral dimension) that goes over the spindle between the final drive and wheel. It's a common mistake to omit this also. But I suspect if you had this going on, it'd be pretty obvious??

 

Sorry, that's about all I got here.

[mark.gilmore]

Do your wheel bearing spacer first,it should be around 113.2mm long,and no shorter than 112.7 for memory

Mark if it hasn't been done before it is almost sure to be to short.

[danl]

Hi guys,

 

Thanks for your comments. I've been waiting for my shop stand to arrive so I could dig in to this thing again before replying again. I'm including some pictures this time to help describe things.

 

Final Drive

The first three show the washer I was asking about. I agree that it only goes on one way, and I can't imagine how one could install it overlapping the race-but it sure seems like that happened at some point. There is even a slight gouge where the washer was installed incorrectly (screwdriver is catching it)

 

My feeling is that the inner race should stick out farther than the washer so that it is compressed along with the other inner races and spacers, and does not rotate.

 

If the washer was wider than the race than it would be clamped tightly between the swingarm and the housing (which must rotate slightly in relation to the swingarm)

 

My worry is that if the spacing on the right side of the ring gear is too short than this would allow the compression of the axle nut to change the preload of the ring and pinion.

 

If I spin the input shaft while trying to push the ring gear to the right (pushing on its L/S bearing race-see photo) I can feel the notchiness I was feeling before. If I then spin the input shaft while pushing the needle bearing race to the left side everything feels good.

 

Wheel Bearings

The test I described before (using an axle, spacers and nut to compress the wheel bearing inner races and spacer) Is somewhat standard practice when seting up BMW wheel bearings, and will usually allow you to feel any bearing strangeness. I believe my mechanic was using a front axle which is a bit shorter, but I don't quite remember

 

I also cant feel anything abnormal when rotating the bearing races by hand now that the wheel is off. I think if the wheel bearings were causing this notchiness I should be able to feel something by hand.

 

The spacer inside the wheel feels pretty snug against the inner faces of the bearings. I can slide it up and down a bit if I try, but it is certainly not rattling around in there.

 

Is it possible to remove one of these bearings to measure this spacer against your guidelines without damaging the bearing?

[Guest ratchethack]

Danl, once again your description is excellent, but each photo is worth a thousand words. I was a little off in my understanding last pass, but much more is clear now.

My feeling is that the inner race should stick out farther than the washer so that it is compressed along with the other inner races and spacers, and does not rotate.

 

If the washer was wider than the race than it would be clamped tightly between the swingarm and the housing (which must rotate slightly in relation to the swingarm)

Now that I see the photo's, I'd misremembered things. A remembery is a terrible thing to (well you know. . .) I b'lieve you've nailed it. Except for the fact that the washer is not clamped tightly at all (despite my prior lack of remembery) -- the washer simply fills a space in the neoprene space made for it without any tension on it at all, and makes reciprocal, small-arc rotations with the bevel drive relative to the swingarm, along with the "floating" bevel drive, as you noted.

My worry is that if the spacing on the right side of the ring gear is too short than this would allow the compression of the axle nut to change the preload of the ring and pinion.

 

If I spin the input shaft while trying to push the ring gear to the right (pushing on its L/S bearing race-see photo) I can feel the notchiness I was feeling before. If I then spin the input shaft while pushing the needle bearing race to the left side everything feels good.

Danl, the end float of the pinion shaft is what determines the bevel gearset lash, and nothing else. What you're describing couldn't possibly have any effect on the bevel gear set at all, nor could it be an indication of problems with the bearings in the drive, to the best of my understanding.

 

If there's any bearings on their way out, I think everything points to wheel bearings as the likely culprit.

 

Now if you have any detectable slack or lash in the pinion (input) shaft, you may well have problems there, and that's another topic altogether. You can easily tell this by rotating the pinion shaft. But I wouldn't expect it unless you've got some terrific mileage on it.

Wheel Bearings

The test I described before (using an axle, spacers and nut to compress the wheel bearing inner races and spacer) Is somewhat standard practice when seting up BMW wheel bearings, and will usually allow you to feel any bearing strangeness. I believe my mechanic was using a front axle which is a bit shorter, but I don't quite remember

Aha! No wonder this sounded so strange. It's Black Forest Black Magic, practiced by Motoren Werke Fahrtwerkers on Motoren Werke Bayerische Schiestkrapfff!!

 

Can't possibly imagine how this provides any value on a Guzzi, but then, that's just me.

I also cant feel anything abnormal when rotating the bearing races by hand now that the wheel is off. I think if the wheel bearings were causing this notchiness I should be able to feel something by hand.

Not necessarily. If the bearings are starting to go out due to a slightly compressed wheel bearing spacer, it's normally not possible to detect with the wheel off, simply because you can't put side loads on the bearings by hand that're much more easily put on it with the wheel in place.

The spacer inside the wheel feels pretty snug against the inner faces of the bearings. I can slide it up and down a bit if I try, but it is certainly not rattling around in there.

 

Is it possible to remove one of these bearings to measure this spacer against your guidelines without damaging the bearing?

Danl, I'm sure this is possible, but I've never done it, and I reckon the effort level would be pretty high relative to the cost of a new bearing. They're so cheap that it might be a good call to have the old ones out for a measurement between inner bearing registers against the length of the spacer to remove all doubt about that part, and new bearings to banish the rest of the doubt, and this time Bob's really gonna be y'er Uncle.

 

Just a coupla more thoughts...hope this helps. I'd take the read of a few others, weigh it all out and not worry too much, regardless. I think y'er in pretty good shape, and you seem to have a pretty good handle on things.

 

Good luck.

[Guest Phil_P]

Guessing that you are going to be buying some rear wheel bearings in the not too distant future, I'd like to point out;

 

www.vxb.com

 

as good guys to deal with. They mail internationally at reasonable cost and their prices are competitive.

 

No connection other than a happy customer.

[Paul Minnaert]

what I don't get clear from you story: you do have the spacer between reardrive and wheel, it falls out when the wheel is taken out, something like 20mm long?

 

but to make things cler, lets talk by numbers, see picture

19.pdf

[danl]

I think you are talking about the spacer between the wheel and the final drive (not pictured on the exploded view) which is in place.

 

I had been thinking that the ring gear was set up using the shim (#25 on expl.view). I dont have the parts book, but if this is true than the part# would probably show different #'s for different thicknesses.

 

Many times, when gears are set up with shims that move the ring gear as (opposed to the pinion) there are shims on both sides. If you use a larger shim on the left you need to then increase the shim on the right to make up for it. (unless you assume the swingarm will just compress enough to take up the slack)

 

I wonder if part #32 comes in different thicknesses? The book makes it look like spacer #5 goes through the center of it but it actually butts right up against it. (it is in my lap as I type this)

[Paul Minnaert]

19 and 25 come in different thickness, thats all.

from outside to in, you have 31-32-5-36 pushed to each other when you tighten up. 5 looks small but is the long spacer. I have 2 speare rear drives here so I can see easy. It is thight to each other when dismounted. Inner bearing 36 is ok?

[danl]

from outside to in, you have 31-32-5-36 pushed to each other when you tighten up.

 

This is how things should be, but now think about what happens inside the final drive when 31 is too short. The clamping force from the l/s of the swingarm is applied to 36, and from r/s of the swingarm is applied to 33-30-2.

 

 

I remember seeing a post a while back where someone else asked about the height of this washer. His washer was like mine, but someone else posted a pick showing the race sticking out farther than the washer (like it's supposed to) I haven't been able to find that post again, but I think the poster may have sold that bike.

 

Phil_P

Thanks for the link to VBX bearings. they look like a really good resource.

 

If everyone else hasn't seen this here is a link to the 6204 2-rs bearings

http://www.vxb.com/page/bearings/PROD/20mm/6204-2RS-1

 

I found bearing site while searching for bearings at work a while back

http://www.ty-coon.com/categories.asp?cat=152

this is a very strange site- it doesn't even say where they are located. They list bearings in different packages 2 6204-2rs bearings are 5.81. If you are really paranoid you could buy 1000 bearings for $1016.40

 

I feel like these must be really low quality bearings at those prices, but I sent off an email anyway asking about brands, nationality, clearances (standard, C3 etc.) If I get a response I will post it here.

 

None of this matters of course, because I am impatient and I want to play w/ the back wheel this weekend so it's off to NAPA!

 

Wheel bearing spacer

 

How many people have had problems with this spacer?

Does it affect certain years, or is it across the board?

Do any suppliers carry an improved spacer for sale, or is it custom for everyone?

If my spacer measures 113.2mm or so do you guys consider it to be "OK"

[Guest ratchethack]

I feel like these must be really low quality bearings at those prices, but I sent off an email anyway asking about brands, nationality, clearances (standard, C3 etc.)

Danl, these bearings are high volume commodity items. They ship to bearing suppliers by the bazillions and are bought and sold down-market in relatively large lot numbers, which drives the market price down, even in low quantity "onesy" order numbers. Don't make the mistake of equating poor quality with a low price here. High quality is indeed available at low prices with high volume commodity stuff (if you know wot y'er doing and know where to look). I reckon the way to think about this is to appreciate that Guzzi at least had the sense and the courtesy to spec. a somewhat "consumable" item like a bearing with a commonly found item used outside motorcycling that can leverage economies of massive scale!!!

Do any suppliers carry an improved spacer for sale, or is it custom for everyone?

If my spacer measures 113.2mm or so do you guys consider it to be "OK"

Per previous threads on this, there's no "off the shelf" upgrade available, but a "custom" spacer is cheap and easy to fabricate by any machine shop anywhere. A measure of 113.8 mm was the "build to" spec on new spacers, if memory serves from when we did one on my Pal's LM. Do confirm this dimension with others, but since there have been slight variations in dimensions of the wheel (between inboard bearing registers), as long as you're going to the effort, the correct way to do this is to have the bearings out, give the wheel a measure, and make the spacer to +.2, +/- .1 mm or so to fit the wheel. This is a non-critical dimension, where any tighter tolerance is of no value, but machining a spacer to fit each individual wheel will give greatest insurance against a repeat problem, and provide greatest confidence down the road.

 

Have fun.

[danl]

Hey everybody,

 

Just a little update for anyone who is interested.

 

I figured it was worth having a look at my bearing spacing, since so many people have reported problems with their own.

 

My bearing spacer measures 4.435" (112.65mm) and it is .013" (.33mm) LONGER than the bearing registers in my wheel.

 

While this does seem a bit long to me, (and I may lap this spacer down a tiny bit) there is no way it was causing the notchiness I was feeling.

 

Last week I sent my reardrive out (as much as it pains me) to a guy on Long Island who specializes in Guzzi gearboxes and reardrives. He has setup fixtures to properly load the crown gear away from the pinion when setting backlash, and I feel that I am in good hands.

 

I will let you know what the outcome is.

[Guest ratchethack]

My bearing spacer measures 4.435" (112.65mm) and it is .013" (.33mm) LONGER than the bearing registers in my wheel.

 

While this does seem a bit long to me, (and I may lap this spacer down a tiny bit) there is no way it was causing the notchiness I was feeling.

 

Last week I sent my reardrive out (as much as it pains me) to a guy on Long Island who specializes in Guzzi gearboxes and reardrives. He has setup fixtures to properly load the crown gear away from the pinion when setting backlash, and I feel that I am in good hands.

 

I will let you know what the outcome is.

I'm with you, Danl. It would seem that there's no possibility of the infamous wheel bearing compression phenomenon at work here. HOWEVER, since you've got the wheel bearings out, and they're so INEXPENSIVE (as opposed to "cheap"! ), it may be a wise move to install new ones simply to remove all doubt going forward. Only you know what that "notchiness" felt like. If I had any doubt that it was coming from the bevel drive, I'd no doubt have welcomed a go at it from a local Pro with some depth of experience, just as you have.

 

Looks like I was off on my recall of the correct spacer dimension. Wot? No surprise?!

 

I'd leave the spacer alone and continue to torque the spindle nut to spec., but that's just me.

 

Good luck, and by all means get back to us on wot y'er Guzzi Gear Guy comes up with WRT setting backlash. To the best of my knowledge, a bad bearing here on a V-11 would be among a mighty skimpy number ever to cross the pages o' this Forum. . .

[danl]

Sorry to leave this thread hanging for so long. Don't know if anyone was interested, but I know it's no fun to search a topic only to find a relevant thread that goes nowhere!

 

I've actually been back up and running since december (although that's only been about 1000 miles due to the cold weather here in philly).

 

The problem was that the sealed bearing in the center of the ring gear (visible from the left with the wheel off) was off of it's seat by about .030". Since the spacer inside the box butts up against the race of this bearing, the spacer was .030" to the left of where it should be. This is why the inner spacer did not protrude through the big washer.

 

I re-seated the bearing, and now the wheel turns smoothly and without noise on the stand and the road! I really should have changed the bearing, but I had to assemble it to check it out and then-well you know how things go. It's somewhere on the list.

 

It seems to me that this is what would happen if you tightened the wheel up with the big washer resting on the axle instead of in its recess. At this point I don't care because It's nice out and my bike is running great!

[Guest ratchethack]

It seems to me that this is what would happen if you tightened the wheel up with the big washer resting on the axle instead of in its recess. At this point I don't care because It's nice out and my bike is running great!

Nicely done, Danl. Thanks for closing the loop on this one. It's a good "heads up" for all of us.

 

IMHO there's no satisfaction like getting to the bottom of things yourself. Not only have you solved the problem, now you have ZERO doubts about it -- as opposed to wondering wot someone else may or may not have done, and having no choice but accepting his version of wot's going on (someone you might not necessarily have had any experience with previously). . . but I digress. . .

 

I b'lieve your observation was correct that this likely occurred when the spindle was torqued when the flat washer that protects the small outboard needle bearing was out of place, resting on the spindle. As you noted, this would have the tendency to push the bearing you refer to off its register.

 

No doubt yours isn't the first occurrence o' this!

 

I would expect an off-center witness mark on the flat washer from the bearing race that's probably still there.

 

In my own case, I've taken care on numerous occasions to "stick" the flat washer in place with BTWBG (boat trailer wheel bearing grease) so it doesn't have a tendency to drop down off the bearing race on the spindle.

 

Good thread. Glad you've been happily riding all this time.