Lower diff bolts torque setting?

[Guest]

I have just discovered that one of the bolts in my LSD has sheared and the other one is loose.

 

I'm getting two new bolts machined tomorrow out of a higher tensile steel but wondered what the correct torque figure is when I come to fit/tighten them up.

 

Thanks.

[Stationary M25 Traveller]

Not at home for access to any figures ... but don't forget to fit washers to fill the gaps between the chassis and the diff each side or they may shear again.

[Mark Durrant]

I know of a few cars that have suffered with either a bolt shearing or missing, in one case leading to the chassis mounts being damaged. The bolt is a M12 x 65mm and the torque setting is 55Nm/40 lbft. I check my lower diff bolts a couple of times a year

[Jonathan Kay]

As above.

 

I'd want to know why this happened and I don't think stronger bolts are needed if the alignment is correct and the bushes are intact and the bolts are correctly fastened.

 

Jonathan

[Mark Durrant]

The bolts over time and depending on use gradually work loose, the diff then moves and the bolt(s) shear. A regular spanner checks prevents this problem.

[anthonym]

I do wish there was a spanner check list - I just found loose and tightened my diff bolts; now it's like a new car.

 

These bolts would have been working loose for many (many) years.

 

[Jonathan Kay]

Quoting anthonym: 

I do wish there was a spanner check list

What should that look like?

 

There is a very useful listing of what's in each fastener pack. Each chapter of the Assembly Guide has a table giving the torque settings for the relevant bolts.

 

Jonathan

[anthonym]

maybe I should have said " spanner check checklist "

[Jonathan Kay]

How about organised by general location (e.g. rear suspension, front suspension, steering, mounts, front brakes, rear brakes) and then within that by head size to minimise the fiddling?

 

Does anyone use dabs of paint to help? Multiple colours?

 

Jonathan