Drive Shaft Pinch Bolts

[justmike]

Can anyone tell me if these are "special" bolts, and what the proper torque specification is (2000 V11 Sport)? Quote from my Guzzi Manual: "Remove the transmission shaft from the gearbox by unscrewing the high resistance screws." Screws came out, but the screw threads are toast - looks like they used permanent loctite on them. I ran a tap throught the u-joint ends - threads look great - but I want to make sure I don't err on the replacement screws.

Thanks!

Mike

[Kiwi_Roy]

screw threads are toast - looks like they used permanent loctite on them. I ran a tap throught the u-joint ends - threads look great - but I want to make sure I don't err on the replacement screws.

Thanks!

Mike

 

Picture attached -

The threads on mine were the same.

The bolts are marked LOBO 12.8 with 2 dots

This is caused by not lining the indent in the shaft up perfectly with the bolt hole.

The bolts catch and destroy the thread.

If you look through the gap between two halves you should be able to line it up.

Sorry, I don't know the torque settings but I doubt it's critical. I just tightened mine

by hand to where It seemed right.

By the way the original bolts were longer than necessary, 25mm is long enough

 

"Tighten them till they strip, then loosen 1/2 turn", just kidding

 

Roy

[gstallons]

Order more capscrew(s) and use Loctite blue upon reassembly. also Loctite sells a "primer" to clean the capscrew threads and bore threads.

[justmike]

Well, I think I'm getting closer. Pretty sure that "high resistance screws" is an Italian translation of "high tensile screws". What I believe are the original screws at the bevel drive end are marked 12.9, while the shiny cad-plated screws at the gearbox end (presumably replaced by whoever did the transmission recall) are marked 8.8, which I've learned is a designation for tensile strength. The 8.8 screws were the ones that stripped - which makes sense in terms of their lower tensile strength. So I'm off to buy four new 12.9 x M8 x 1.25 pitch x 30mm. long socket head cap screws. Now, torque spec anyone? I've found that the fastener can be torqued to 49 Nm., but what about the threads in the forged u-joint knuckle - what are they good for?

 

The blue loctite is a great idea - I was already going that route. Not so sure about the torque until stripped and back off 1/2 a turn

[docc]

I remember taking mine apart a several years ago and the threads were *very unhappy*. I reassembled with blue LocTite and the torque spec for the bolt size (are they 6mm or 8mm??)

 

I, then, painted a red line along the bolt heads onto the knuckles so I could monitor if the bolts tried to back out. So far, no.

[raz]

39 Nm in my WHB. Should be the same for a V11.

[justmike]

39 Nm in my WHB. Should be the same for a V11.

 

That seems to be in the right ballpark - works for me. You're the man raz - thank you.

[docc]

Different shaft on the 1100, no? Yet the pinch bolts may be the same (?)

 

The V11 bolts appear to be 8mm. The Workshop Manual shows 25-30 nM for 8x1.25 bolts.

[raz]

Different shaft on the 1100, no? Yet the pinch bolts may be the same (?)

 

The V11 bolts appear to be 8mm. The Workshop Manual shows 25-30 nM for 8x1.25 bolts.

Yes but that "standard torque value" is for 8.8 grade bolts.

 

It's true the V11 have a different shaft and even a different number of splines. On the other hand, both have 12.9 grade M8 bolts. I admit not knowing for certain but personally I would use the 39 Nm. I torque them in two-three steps so they get equal.

 

Edit: I have a "standard torque value" chart from GM that I found somewhere on the Net. For 12.9 lubed, it says 40 Nm.

[docc]

Yes but that "standard torque value" is for 8.8 grade bolts.

 

It's true the V11 have a different shaft and even a different number of splines. On the other hand, both have 12.9 grade M8 bolts. I admit not knowing for certain but personally I would use the 39 Nm. I torque them in two-three steps so they get equal.

 

Edit: I have a "standard torque value" chart from GM that I found somewhere on the Net. For 12.9 lubed, it says 40 Nm.

And the three steps is a good method since one pinch bolt will loosen as the other is tightened. True for triple clamps on the forks as well.

 

I've likely undertorqued mine. I keep checking those red lines and, so far, no backing out. The manual also calls for a shaft replacement every 20,000 kM (12,000 miles)! I should be on my fifth shaft. I remember Greg saying he'd seen a shaft failure. Not good. Still, it's going to hard to pull out a shaft while it's still "good." They must be pricey . . .

 

BTW, what is "WHB?"

[justmike]

Yes but that "standard torque value" is for 8.8 grade bolts.

 

It's true the V11 have a different shaft and even a different number of splines. On the other hand, both have 12.9 grade M8 bolts. I admit not knowing for certain but personally I would use the 39 Nm. I torque them in two-three steps so they get equal.

 

Edit: I have a "standard torque value" chart from GM that I found somewhere on the Net. For 12.9 lubed, it says 40 Nm.

 

Good call on the "standard torque value" for 8.8 grade bolts - I agree. I think the manual's reference to "high resistance bolts" confirms what you're saying about the 12.9 grade - they must me differentiating for a reason. I installed mine with Loctite blue paste, and torqued to 39 Nm. - felt good going together (in three steps ) - hopefully it'll stay together.

[raz]

BTW, what is "WHB?"

 

Workshop HandBook

[docc]

That is a very nice diagram. One of the greatest shortcomings of the V11 Workshop Manual is the notorious absence of these assembly diagrams complete with torque values.

 

Perhaps the CD-ROM Manual I have is different. I've only ever used the "four ring" hard copy binder.

 

It's much more fun to put greasy fingerprints on than a silly CD!

[raz]

I mostly prefer PDF manuals over paper ones. My laptop has to suffer a little from greasy fingers though

 

The thing I like most about PDF manuals is that I'm able to search them. Sometimes that makes a world of difference. Torque numbers is a good example by the way. There is one page in my WHB with torque numbers for many things, as well as those standard numbers. But then there are a lot of others scattered in the diagrams like the one I posted. Searching for 'kgm' I quickly found them all and added them to my own chart.