850 T GEAR BOX LAY SHAFT LH THREAD TORQUE

[Guzzi2Go]

So I have a problem with my gearbox refurbishment that leads to this question. What is the Torque setting for the Lay Shaft LH retaining nut? My research and the Workshop manual says 115 to 129 ft/lbs. At 90 ft/lbs. I stripped the thread on a new nut just purchased from MG Cycle. Bad aftermarket product or is the 115-129 ft/lbs suspect?
I've been refurbishing the gearbox on my 850 T this past winter and am reassembling it now. The old lay shaft LH thread retaining nut was a bit chewed ( see pic) so I thought it would be a good idea to replace it. It was also loose on the shaft when I pulled the gear box apart. So it definitely had been opened before. So the 115 to 129 ft/lbs is correct? Should I try Harpers or somewhere else for the nut? Any suggestions?

PS I've reviewed the various posted threads pertaining to the 5 speed gear boxs and haven't come across anything specific to this question. My apologies in advance if i have missed it.

 

[V700Steve]

I would buy 5 and use blue loctite. Maybe get from a different source also. I do the nuts at 120ftlbs.

Nuts ain't like they used to be. I find loose nuts on 5 sp that have never been apart.

 

[Guzzi2Go]

Thanks. I’m kicking myself only buying one.

 

[scottmastrocinque]

One possible explanation of your experience may simply be something that I have seen many times.

The very popular “click” torque wrenches, all of them, require periodic calibration in order to accurately determine torque correctly.

I would annually send my wrenches out for calibration and adjustment.

If the wrench you are using is older and never been calibrated, it may be displaying a lower value than you are actually applying and this may have been the proximate cause of the nut being damaged.

If you can, you might want to use a newer torque wrench. Perhaps a friend might have one?

A nifty trick I use is a digital in-line torque adapter instrument with an audio indicator. They are used when you must apply a torque “blind” because it is impossible to see a display or there is insufficient room for a regular torque wrench to fit.

(It is amazing how often different wrenches can be wildly off.)

Also, remember that all torque values are presumed to be on perfectly dry threads. If the thread has anything on it, the actual true torque value will be greater than indicated on your wrench due to slippage from the liquid.

I hope this helps you and I wish you Good Luck.

Torque Wrench Calibration | Why, When & How - Complete Guide

We bring a complete guide on torque wrench calibration from the basic concept of calibration to calibration certificates, we explain it all.

handytooladviser.com

 

[Amboman]

That torque figure (115-129) is for the right-hand thread nuts in the clutch and output shafts, not the left-hand thread nut on the front end of the output shaft! If you look down at the bottom of the Gearbox list, you'll see the correct torque: "nut, safety" 50-57 ft. lbs.

I've used that same nut, from the same source, and have never had an issue when it was >torqued correctly<!

 

[Guzzi2Go]

One possible explanation of your experience may simply be something that I have seen many times.

The very popular “click” torque wrenches, all of them, require periodic calibration in order to accurately determine torque correctly.

I would annually send my wrenches out for calibration and adjustment.

If the wrench you are using is older and never been calibrated, it may be displaying a lower value than you are actually applying and this may have been the proximate cause of the nut being damaged.

If you can, you might want to use a newer torque wrench. Perhaps a friend might have one?

A nifty trick I use is a digital in-line torque adapter instrument with an audio indicator. They are used when you must apply a torque “blind” because it is impossible to see a display or there is insufficient room for a regular torque wrench to fit.

(It is amazing how often different wrenches can be wildly off.)

Also, remember that all torque values are presumed to be on perfectly dry threads. If the thread has anything on it, the actual true torque value will be greater than indicated on your wrench due to slippage from the liquid.

I hope this helps you and I wish you Good Luck.

Torque Wrench Calibration | Why, When & How - Complete Guide

We bring a complete guide on torque wrench calibration from the basic concept of calibration to calibration certificates, we explain it all.

handytooladviser.com

View attachment 35119

That torque figure (115-129) is for the right-hand thread nuts in the clutch and output shafts, not the left-hand thread nut on the front end of the output shaft! If you look down at the bottom of the Gearbox list, you'll see the correct torque: "nut, safety" 50-57 ft. lbs.

I've used that same nut, from the same source, and have never had an issue when it was >torqued correctly<!

yikes I'll definitly have to review that. I was sure that the

One possible explanation of your experience may simply be something that I have seen many times.

The very popular “click” torque wrenches, all of them, require periodic calibration in order to accurately determine torque correctly.

I would annually send my wrenches out for calibration and adjustment.

If the wrench you are using is older and never been calibrated, it may be displaying a lower value than you are actually applying and this may have been the proximate cause of the nut being damaged.

If you can, you might want to use a newer torque wrench. Perhaps a friend might have one?

A nifty trick I use is a digital in-line torque adapter instrument with an audio indicator. They are used when you must apply a torque “blind” because it is impossible to see a display or there is insufficient room for a regular torque wrench to fit.

(It is amazing how often different wrenches can be wildly off.)

Also, remember that all torque values are presumed to be on perfectly dry threads. If the thread has anything on it, the actual true torque value will be greater than indicated on your wrench due to slippage from the liquid.

I hope this helps you and I wish you Good Luck.

Torque Wrench Calibration | Why, When & How - Complete Guide

We bring a complete guide on torque wrench calibration from the basic concept of calibration to calibration certificates, we explain it all.

handytooladviser.com

View attachment 35119

Actually its a brand new torque wrench. 50 to 250 ft/lbs, with calibration certificate. my old one is only a 3/8" drive rated to 80 ft/lbs. A bit light for the Norge rear wheel bolts and this work. I like these digital torque adapters though. nice idea.

 

[Guzzi2Go]

That torque figure (115-129) is for the right-hand thread nuts in the clutch and output shafts, not the left-hand thread nut on the front end of the output shaft! If you look down at the bottom of the Gearbox list, you'll see the correct torque: "nut, safety" 50-57 ft. lbs.

I've used that same nut, from the same source, and have never had an issue when it was >torqued correctly<!

Yikes! how did i miss that! What did someone say..."Its done right because I do it twice." sigh. Thanks for catching my mistake.