Pete Roper saves the day - probably not for the last time !

[Alex-Corsa]

 

For this reason it is important to make sure that the trunnions line up like so

+------------+

 

Not like so

 

x-------------+

 

V11's have the paint marks to help. On earlier machines I believe one relies on the grease nipples being in line or simply guaging everything up by eye.

 

Pete

 

Thanks Pete for your time and explanation. To make the long story short (as far as I understood) at the pic. I posted the 2 pos. the shaft is alligned, right?

never noticed that in my Guzzi, will have to look tomorrow.

[Alex-Corsa]

 

For this reason it is important to make sure that the trunnions line up like so

+------------+

 

Not like so

 

x-------------+

Pete

 

Have checked my bike an the allignment is like so

+---------+

Thanks Pete

[mike wilson]

The needle rollers in the caps are lubricated by grease, hence the grease nipples, and this is retained in the caps by oil seals on the inner, trunnion end, of the caps. While most people when greasing the couplings simply pump grease in until it blurts out round the eals this isn't actually the way it should be done. By the time it's splurting out it's obviously buggered the seal! Grease should be added only until the seals can be seen to swell a little bit, this DOESN'T require much grease!

 

I do the blurt but not from thoughtlessness. Having seen the colour of the grease coming out compared to new stuff going in, I feel happier knowing that as complete an exchange of lubricant as possible has taken place. To return the seal to some form of working (my joints are all internal, so it's not quite as important) I work the joints in all directions whilst massaging the seal. It's as much fun as chasing sheep and far less energetic. The end result doesn't make me feel quite as good but it's more satisfying intellectually.

[Guest ratchethack]

While most people when greasing the couplings simply pump grease in until it blurts out round the eals this isn't actually the way it should be done. By the time it's splurting out it's obviously buggered the seal! Grease should be added only until the seals can be seen to swell a little bit, this DOESN'T require much grease!

OK, confession time.

 

When I grease U-joints, it's usually in a place where there ain't much light, and the Guzzi is no exception. I've always been careful not to over-pressurize the seals by overdoing it with the grease gun, but I invariably wind up adding grease until a quantity of old grease comes out. This is no doubt past the point where the seals would be bulging -- if I could see them bulging around corners, in a dark and nearly inaccessible place!! Since I can seldom even see the seals when doing this, I reckon a massage (as stimulating as that sounds, Mike) would be out o' the question without removing the U-joint!!

 

So now the question is this: With these U-joints specifically, can the above procedure pop the seal out of correct orientation and create lack of seal, and if so, is this something I should be concerned about, or are the seals likely to work themselves back into place with use?

 

Enquiring minds -- well, you know. . . . .

[raz]

 

Have checked my bike an the allignment is like so

+---------+

Thanks Pete

Consider yourself lucky... I'm sad to say I didn't have that luck. 90 degrees out. Why settle for less than worst case?

 

Sh*t. At the very best it may have happened at the tire change 6000 km ago. With less luck, who knows for how long. Where do I rattle and rock to check for damage? What would be considered too much play?

 

Thanks Pete! As the thread said: probably not for the last time!

 

EDIT: Wait a minute, re-reading the whole thread makes me hoping that 45 degrees would be worst case... is that right Pete?

[Alex-Corsa]

Consider yourself lucky... I'm sad to say I didn't have that luck. 90 degrees out. Why settle for less than worst case?

 

Sh*t. At the very best it may have happened at the tire change 6000 km ago. With less luck, who knows for how long. Where do I rattle and rock to check for damage? What would be considered too much play?

 

Thanks Pete! As the thread said: probably not for the last time!

 

EDIT: Wait a minute, re-reading the whole thread makes me hoping that 45 degrees would be worst case... is that right Pete?

 

I can concider myself lucky? but why that, ? I had a service made in the schaft ( inner -gear box nipple replacement) so the mech. who did it in Germany really deserved their 40/50Eur/hour, they asked, I suppose.

It seems to me(miss-allignment) unlikelly to happen to a tyre change, since the bevel stays in the swingarm untouched.!

 

Now, that occassion with blowing the seals from grase sounds interesting.I kepd doing it most times, how bad ist it doc.?

[Guest ratchethack]

Wait a minute, re-reading the whole thread makes me hoping that 45 degrees would be worst case... is that right Pete?

Well, Pete had his say and I had mine. Now who y'gonna b'lieve.

 

Er, hold on. Scratch that.

 

OK, think of it this way:

 

Here we have the marks aligned:

 

+--------+

 

Here we have the marks 180 degrees to each other. See the resemblance? (no functional difference from aligned):

 

+--------+

 

Half-way between is worst case, +/- 90 degrees:

 

+--------x

 

Now here's a visual aid of correct alignment (by courtesy of Alex) to remove all doubt:

[raz]

Well Pete had his say and I had mine. Now who y'gonna b'lieve.

 

Er, hold on. Scratch that.

I was actually hoping for a raging battle between the two of you

 

Here we have the marks at 90 degrees to each other:

 

+--------x

 

Well, no... that would be 45 degrees unless my brains stopped working altogether. Not? I tried googling some but I found no definite answer. 45 degrees would be very bad, that's for sure. But I'm not too sure about 90. I will line it up anyway just because I'll take any excuse for getting oil under my nails.

[Guest ratchethack]

I was actually hoping for a raging battle between the two of you

 

 

Well, no... that would be 45 degrees unless my brains stopped working altogether. Not? I tried googling some but I found no definite answer. 45 degrees would be very bad, that's for sure. But I'm not too sure about 90. I will line it up anyway just because I'll take any excuse for getting oil under my nails.

Raz, the x and + are 2-dimensional representations of a 3-D concept, since 2-D's all we've got to work with using alphanumeric symbols. But if you imagine a 3-D ISOMETRIC VIEW, it can represent a shift of 90 degrees. It's easier to look at Alex's photo and imagine ONE END ONLY rotated 90 degrees to the other, and you have worst case scenario.

 

Be careful when you look at sine wave representations of U-joints. It's easy to get confused. The typical x and y-axis graph will show the sine wave of the angular velocity change through a single joint. We're talking about 2 joints and the degree of change BETWEEN THEM from perfect alignment, where the PHASE SHIFT of the sine wave of one joint exactly cancels the other.

 

I reckon if Pete thinks about it, he'll come around to my point of view. . . . or not, but I'm still right.

 

That's my story, and I'm stickin' to it. . . . .

 

Hey Pete, you were the perfect Gent about it, but I wound up voluntarily (and rightfully so) eating crow on the great coefficient of heat expansion of brake fluid argument way back when. You were right and I was wrong, as I proved to my own satisfaction in the Infamous Hatchracket Laboratory with Erlinmeyer flask, pipettes, Bunsen burner, and industrial thermometer. If you recall, I'd posted my results along with concessions to y'er wealth of superior knowledge of such matters. You'll also I recall I did so with humility and apologies for doubting The Master.

 

But if y'er gonna take me on on this one, I'm gonna hafta bring in driveshaft expertise from automotive driveshaft types who've been lining up U-joints since Hector was a pup (. . . uh, kinda like y'erself!), but I reckon y'er not gonna win this one.

[Alex-Corsa]

Well, Pete had his say and I had mine. Now who y'gonna b'lieve.

 

Er, hold on. Scratch that.

 

+--------+

 

Here we have the marks 180 degrees to each other. See the resemblance? (no functional difference from aligned):

 

+--------+

 

 

Yep that"s how mine are on the bike , like in the photo though the front shaft grase nipple (gearbox side)

turned exact 180deg (than on the photo), still lined up +-------+

Thanks Ratchet for complementing.

[raz]

Be careful when you look at sine wave representations of U-joints. It's easy to get confused. The typical x and y-axis graph will show the sine wave of the angular velocity change through a single joint. We're talking about 2 joints and the degree of change BETWEEN THEM from perfect alignment, where the PHASE SHIFT of the sine wave of one joint to the next exactly cancels the other.

 

I reckon if Pete thinks about it, he'll come around to my point of view. . . . or not, but I'm still right.

 

That's my story, and I'm stickin' to it. . . . .

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml seems to be a good page for understanding this, even with animations. Not that I have digested it all yet (this means I'm leaning towards you're right but I haven't mentally accepted it yet )

 

One thing's for sure anyway: my bike does not handle bad. At all. If this is worst case, it should.

[Alex-Corsa]

Here is a representation I shot for you with 45deg and 90 degree(compred to the photo situation2 posted before(, turn over of the front joint.

Notice the ending join holes how differently dissalign. Even thoguh only on 100% allignment is on 0 and 180degr compared to again as photo 2 of previous example is.

Notice that they too create or belong to a line or "axle"

hope that helps and sure ratchet can give a better description than I did.

Here you go.

 

 

Degrees are about the closest since there aren't many or enough teeth for the other "bone end" to be brought to 90 or 45 deg.It is made so and it seems to me they allign exct face to face only in the 0 and 180 degr. set up.

[Guest ratchethack]

. . . it seems to me they allign exct face to face only in the 0 and 180 degr. set up.

That's the ticket, Alex -- exactly right. Superb visual aids, BTW!

 

Many thanks!

 

But it looks like y'er off a spine on the 90 degree shot??

 

EDIT:

Degrees are about the closest since there aren't many or enough teeth for the other "bne end" to be brought to 90 or 45 deg.It is made so and it seems to me they allign exct face to face only in the 0 and 180 degr. set up.

I b'lieve I understand now. It's a half-spline off in the photo. There aren't enough splines on your 10-spline shaft to allow 90 a degree misalignment, since 1/4 x 10 = 2.5. Nor are there the right number of splines to allow a 45 degree misalignment, since 1/8 x 10 = 1 1/4.

 

But since the V-11's have 20 splines, there are enough splines on the V-11 shafts to allow a 90 degree misalignment, (1/4 x 20 = 5) -- but not enough splines to allow a 45 degree misalignment (1/8 x 20 = 2 1/2). Got that?

 

Doing a Web search, I discovered that Chevrolet actually purposely misaligned their driveshafts for many years by 15 degrees in an attempt to reduce harmonics (this gets fairly complex) but finally discontinued the practice because it wasn't effective.

 

It's an illustration that you can be off by a little without much of a negative consequence.

 

On the V-11's, 1 spline = 9 degrees. You could be 2 splines out and probably never notice.

 

On the pre-V-11 Sport carb & Sporti, 1 spline = 18 degrees. You could be 1 spline out and probably never notice.

 

Again -- 90 degrees misalignment is the max danger zone, Gents! Stay far far away! Better yet, align the marks.

[raz]

That's the ticket, Alex -- superb visual aids.

 

But it looks like y'er off a spine on the 90 degree shot??

 

EDIT: I b'lieve I understand now. It's a half-spline off in the photo. There aren't enough splines on your 10-spline shaft to allow 90 a degree misalignment, since 1/4 x 10 = 2.5. There are enough on the V-11 shafts, which have 20 splines (1/4 x 20 = 5). Got that?

 

Doing a Web search, I discovered that Chevrolet actually purposely misaligned their driveshafts for many years by 15 degrees in an attempt to reduce harmonics (this gets really complex) but finally discontinued the practice because it wasn't effective.

 

It's an illustration that you can be off by a little without much of a negative consequence.

Yup, I just realized that. Even if 90 degrees is more or less as good as 0 degrees, my misalignment must be 72 or 108 degrees and that's in the range of Greggs. Well well. Thanks a lot Alex and Ratch. By the way Alex, of course you're right it should not be called luck, but it seems even Guzzi dealers miss on this. Anyway I had bad luck. Either it was this way when I bought it, or the jap-bike-mechanic that changed my wheel removed a little too much before sorting out how it should be done. He seemed to be an experienced guy. I was a Guzzi newbie at the time so I had no idea.

 

One positive outcome though... could my Guzzi be an even better ride now? That must be a dream!!

[Guest ratchethack]

Thanks a lot Alex and Ratch.

As we say in the Republik of Mexifornia, Por nada.

. . .Either it was this way when I bought it, or the jap-bike-mechanic that changed my wheel removed a little too much before sorting out how it should be done. He seemed to be an experienced guy. I was a Guzzi newbie at the time so I had no idea.

It seems there are chimpanzees with hammers behind closed doors of moto shops in Sweden also, Raz -- just like wot we got here.

 

NOTE: No offense whatsoever meant to our highly esteemed and respected Professional Guzzi Shop Proprietors! You set yourselves far apart from the Philistines every day!