Rear axle tightning procedure

[CollingsBob]

What is the difference between tightning the rear axle with the pinch bolts tightened vs holding the rear axle with an Allen wrench while tightning it, and then tightning the pinch bolts?
Is there a pre-load on bearings that is done one way, but not the other?

[FJRoss]

One is right and the other is wrong

I usually snug up the pinch bolt just enough so the axle doesn't turn while tightening. Back off the pinch bolt after the wheel nut is fairly tight and then torque the wheel nut to spec. (Then do the final tightening on the pinch bolt) I haven't needed the Allen wrench to hold it.

Final torqueing with the axle held by the pinch bolt does not put the loads where they are supposed to be but I don't know what the consequence might be. The usual torque procedure pulls the head of the axle to the washer that pulls the wheel to the left side. There is nothing that would (or should) pull the right side of the swingarm in. Doing the final torque with the pinch bolt tightened pulls the RHS of the swingarm in to the wheel. In addition, if the axle wasn't fully seated and slips a bit, the torque will end out too low. The pinch bolt is meant to prevent rotational movement, not lateral movement in the axle.

I do the same with the front - pinch bolt for temporary (initial) tightening. Back it off, torque axle to spec and then torque pinch bolts to spec in the specified order.

[CollingsBob]

Interesting...on the Vincent the axle nut is indexed into the swing arm by a tab, thereby restricting its rotation and the axle has a large tommy bar - tightened by hand, then given a good boot for final tightning.
If only Yamaha had indexed the nut in the same manner..

[wheatonFJR]

One is right and the other is wrong

I usually snug up the pinch bolt just enough so the axle doesn't turn while tightening. Back off the pinch bolt after the wheel nut is fairly tight and then torque the wheel nut to spec. (Then do the final tightening on the pinch bolt) I haven't needed the Allen wrench to hold it.

Final torqueing with the axle held by the pinch bolt does not put the loads where they are supposed to be but I don't know what the consequence might be. The usual torque procedure pulls the head of the axle to the washer that pulls the wheel to the left side. There is nothing that would (or should) pull the right side of the swingarm in. Doing the final torque with the pinch bolt tightened pulls the RHS of the swingarm in to the wheel. In addition, if the axle wasn't fully seated and slips a bit, the torque will end out too low. The pinch bolt is meant to prevent rotational movement, not lateral movement in the axle.

I do the same with the front - pinch bolt for temporary (initial) tightening. Back it off, torque axle to spec and then torque pinch bolts to spec in the specified order.

If all the pinch bolt is doing is preventing the shaft from rotating, how is that different from your allen wrench preventing the shaft bolt from rotating, while the other end rotates the nut and stretches the shaft bolt. The shaft bolt doesn't see any different force...all it knows is that it is getting stretched uncomfortably tight. It doesn't care if the pinch bolt is preventing rotation or the allen wrench thingamabob is doing it. Mebbe you got sumpin there, but ah don't see it.

[FJRoss]

Lets say the axle isn't fully "seated" against the washer and the RHS of the wheel. Tighten the pinch bolt and then torque the axle. You have now pulled the RHS of the swingarm toward the wheel. Not what is supposed to happen. Now, if that pinch bolt "slips" a bit, the swingarm can spring back somewhat and the torque on the axle bolt will be less than it is supposed to be. The head of the axle against the washer, against the ABS housing, against the wheel is where the stresses are supposed to be applied - not while pulling the swingarm in. As I mentioned, the pinch bolt on the RHS of the swingarm keeps the axle from rotating AFTER everything is already torqued to spec. (Probably not even strictly necessary)

Or, maybe I'm wrong...

[CollingsBob]

I loosened the pinch bolt with my pinky against the end of the axle and the swing arm..when the pinch bolt was loosened I felt the axle move inwards, not much..maybe a thou, but thats obviously a thou too much.
Allen wrench for rear axle purchased..

[wheatonFJR]

Yep. I use the allen head for the rear axle now after years of doing it the other way.

I see that the pinch bolt is not only restraining rotation but restraining lateral movement as well...the light has gone on.

[Intech]

The pinch bolt is not designed to hold against the pressure of the proper torque for the axle bolt. After having to helicoil repair a swingarm with a broken pinch bolt (not mine) I purchased the correct hex wrench for the axle. Using the pinch bolt you have to tighten it a lot tighter than the specified torque. Not a good practice.

[bigjohnsd]

The pinch bolt is not designed to hold against the pressure of the proper torque for the axle bolt. After having to helicoil repair a swingarm with a broken pinch bolt (not mine) I purchased the correct hex wrench for the axle. Using the pinch bolt you have to tighten "it", the pinch bolt, a lot tighter than the specified torque. Not a good practice.