Incorrect Torque figure for Sprocket Nuts!

[Speedy1959]

Hi all,

I remember on my old GSX replacing the Chain and Sprockets..

When I tightened the rear Sprocket Nuts to the recommended torque of 102Nm they stripped !!
I am sure this is an incorrect torque figure and WAY too high!

The nuts are M12 (X5)
In Suzukis own "Service chart" it clearly states for M12 sized Bolts a Torque of 45Nm !!!
And if using the High Strength grade 7 bolts that figure goes up to 85Nm

Before anyone jumps down my throat, lets use a little common sense here..
The Rear Axle nut is an M25 which has a torque of "only" 100Nm !!
So how on Earth can a Nut of half the size have an even higher torque ?

I remember when I got my new nuts I used a Tightening Torque of 55Nm which was plenty.
I have talked to several trusted mechanics and they all agreed "That cant be right".

Below are the figure copied and pasted from Suzukis own manual!

Chain Adjustment Bolt M8x50 (2 off) -

Chainguard (rear bolt) M6x10 button (1 off) -

Chainguard (front bolt) M6x25 button (1 off) -

Rear Axle Nut M25x1.5 (36mm socket size) 100Nm

Rear Sprocket Nuts M12x1.25 pitch (5 off) 102Nm

Rear Brake Caliper Housing M10x45 1.25 pitch (2 off) 37Nm

Rear Brake Caliper Mount M8X30 (2 off) 26Nm

Rear Brake Nipples M8x1.25 pitch (2 off) 8Nm

Lower Rear Suspension Mount bolt M10x45 (2 off)

Lower Rear Suspension Mount nut M10 (2 off) 34Nm

[Eric GSX1400K3]

102 for an M12 is way too high.   I'd stick with 45Nm (dry, no thread lube as this only increases the preload on the bolt)

[Notty]

Simon is back !!! 

[gsxbarmy]

102Nm for the rear sprocket nuts is correct, this has been discussed on here before and referred to Suzuki themselves for clarification. The lower torque shown in the manual is a typo and refers to the GSX-R

https://gsx1400owners.org/forum/index.php?topic=6865.0

Verified Torque settings for a good selection of mainly used nuts etc is here

https://gsx1400owners.org/forum/index.php?topic=223.0

[Nic]

How do we know the person at Suzuki wasn't just someone who looked at the manual??
Trust no one 
Have you ever gone into a shop, any old shop'll do. You ask some tard employee, have you got this or that? The expression on their face shows straight away, they don't have a clue what it is you're looking for, then they say, no we don't have that.
Just sayin.
Unless it's a head nut/bolt or an engine bearing nut/bolt, I'll just use my arm duddler.

[gsxbarmy]

How do we know the person at Suzuki wasn't just someone who looked at the manual??
Trust no one 

I queried this with Suzuki GB Tech Support a few years back, pointed out the discrepancies in the workshop manual and asked which was correct and was assured that 102Nm was correct. If you read through the link to the previous discussion on here I marked above, another member also confirmed that this year with Suzuki.
The reason I had the conversation some time back was that this has been a topic of much conversation over a few forums I've been on (not just this one) over the past years - certainly since I've been involved with GSX1400's (almost 17 years)) and the collective answer, confirmed as above by Suzuki was that 102Nm was correct.

That's what I torqued up to when I changed the chain and sprockets on a few GSX1400's and never stripped one once.

No doubt this discussion will continue on on this thread, but at the end of the day, it's your choice. All I can say is that the official torque, confirmed by Suzuki more than once, is that the rear sprocket nuts should be torqued to 102Nm.

[Speedy1959]

I will stick to 55Nm as my nuts stripped out when I tried 102Nm (All of them! Not just 1).
Its a ridiculous amount when the force of the sprocket isnt even pulling outwards.

I accept I will "probably die" due to the lower torque figure..
But at least I will die with my Nuts intact!

S

[Hooli]

I'll stick to 'feels tight' & loctite. It's always worked for me.

[grog]

Exactly my thoughts also. Ive done up a few bolts.