32 replies to this topic

[Vipernoir]

I've measured a few sets of bearings from assorted suppliers (including R&D test kits) and the MS Timken ones (as are most to be fair) are pretty spot on with matched bearings & spacers tied together to prevent them being swapped about.

 

The problem is that they can be 100% accurate to the technical spec all day long and still not fit properly...
How many of us measure the hub for wear ??

If the centre step in the hub is damaged or worn, the spacer needs to be adjusted to suit to get the correct preload.

 

Similarly, does anyone ever check the fit of the drive flange on the CV joint to ensure it will pull up far enough ?
I know there was a batch of very dodgy CV about 4½ years ago that physically prevented the bearing from being pulled up tight.

[tiger99]

That is very good information, and it certainly explains many, probably most, cases of loose bearings. However those which are too tight, including a number of rear hubs recently, will have a different cause. One day we will find out what. It would seem to involve wrong spacers, but we don't have the proof, yet....

Edited by tiger99, 21 January 2014 - 01:57 PM.

[Vipernoir]

Having delved into this a bit in the last year, my suspicions are that the inner race is too thick on the tight bearings - which are usually rear ones - as the spacers are nominally correct.

Surface grind a smidge off the back of the outer race and they can be torqued to spec and not bind.

 

The el-cheapo Chinese ones also have very soft spacers which deform and lose pre-load.
You shouldn't be able to use a hacksaw or file on a bearing...