Diff Tie Rods

[wobblyweb]

I have the rear suspension stripped on my S4. Looking at the diff tie rods, the chassis bolt/nut does not have a lock nut, it has the conical washer and a nut and spring washer. Should the tie rod be free to swing up and down with the diff movement. I suspect it should.

What is the correct procedure for this assembly? fit a nyloc that allows the tie rod to move?

Thanks

Rae

[gjz30075]

Rae, I think that's the purpose of the diff 'tie' rods, also called torque rods. They are to minimize the up and down movement, from torque, of the diff nose. Hence, they should be tight. I don't have the shop manual with me now but there may even be a torque spec for them.

[gerrym]

Rae, there should not be any relative movement between the tie-rod and the chassis at the chassis end. The conical washer is fitted because the tie-rod makes an angle to the chassis where it is secured. (if you look at the end of the tie-rod, there is a conical spherical hollow that matches the washer). Again there should not be any diff movement. That's why the tie-rods are fitted, they provide a torque reaction.

Regards

Gerry

[rgh0]

While the conical washer allows for any tolerances on the angle of the tie rod to the chassis bolt it main purpose is to ensure absolutely no freeplay in the bolted joint. The compression of the conical washer on to the bolt and tierod ensures that no movement occurs between power on and power off. Any freeplay at all and this joint soon flogs itself out and the bolts wear and break and the tierod holes go oval.

The use of conical washers in this sort of assembly situation is common in cars and transmissions - my Landcruiser has a similar set of conical washers in the assembly of where the driveshaft joins the front hub.

cheers
Rohan

[wobblyweb]

Thank you all for your help, it makes sense now that it is explained to me.