7 replies to this topic

[bikenutmart]

Hi, Im building up my new rear subby,I fitted the new radius arms and torqued up the inner pivot spindle nut to 53 ft lbs as per the manual,the arm moves up and down perfect, my question is how tight should the outer spindle nut be, as i started to tighten it up to (about 15lbs)  the arm started to get tight. Any help greatly appreciated Martin.

[tiger99]

The torque is the same, as I think you suspect. The problem would seem to be that the shoulders on teh pivot pin are too close together, by a couple of thou perhaps, or the radius arm is too wide by the same amount.

 

It is worth checking that the outer faces of the arm are clean, with no rust, and the bush and needle roller bearing are pressed in flush or very slightly below. Also the grooved face of the thrust washers must be inwards, but I imagine that you have done all that correctly.

 

So what to do? It may be possible to make a thin shim to fit over the threaded end, under the thrust washer, diameter no greater than the pivot shaft. Or. you could take a thou or two off the radius arm. It ideally ought to be done with some kind of tool running in the bearings to keep the outer faces perpendicular to the shaft. For instance, you could make a cutter out of a spare thrust washer, and put a couple of slots in it, with cutting edges. With the arm held in a vice, bolt the modified washer to one end of a pivot shaft, insert and spin.

 

Or use a good washer and just temporarily add a ring of abrasive paper, glued on. You likely only need to shave a couple of thou off the arm, but try a little bit at each end to clean both sides up.

[bikenutmart]

Thanks tiger99, forgot to say there was a pack of thin shims supplied with it, so if i remove outer nut and spring washer and the 4 bolts holding on the retaining bracket, i could insert the shims by trial and error behind the grooved thrust washer until i am able to get 53lbs on the nut and free movement of the radius arm? Is this correct? Many thanks, you have been a great help. Martin.

[bikenutmart]

Many thanks for the replies. Martin.

[Dan]

  Out of interest were the thrust washer faces new out of the packet or were they greased?  And did you grease the shaft before fitting it?

[tiger99]

I am surprised that there are shims, as I have never seen these before. But they should sort out the problem. You should probably allow about 1 to 2 thou of end float with it torqued up.

[A-Cell]

I've never seen shims. Who supplied the arms? Is the subframe genuine? I would make some measurements to establish the root cause.

[bikenutmart]

The subby is a pattern part, i bought 2 overhaul kits and my local machine shop fitted the bearings and did the reaming, they are well respected!!,the thrust washer was new out of pack and i greased it and the pin before fitting, there was a couple of packs of shims which i didnt use initially but it now seems they are neccessary, i will keep you all updated, but may not be in the workshop for a couple of days. Cheers Mart.