Rear Hub Bearing inner race

Before I took the hub apart I checked end play was at zero, I also noted that the inner wheel bearing races were not seated all the way home in the hubs, there was a noticeable gap. My initial question was how could you set end float if tightening the axle shaft could pull the inner race further into the hub? So I dismantled everything, cleaned and got all new bearings except outers. Upon reassembly I was wondering about the inner races again and bought a tool JD550-1 that looked like it would work well. It fits perfectly and has the step to drive the race in to what looks like the same position as it was before, but I still don’t understand why it wouldn’t be pulled in further by compression when tightening the axle nut.
Should the inner race be driven in all the way home? Sure seems like it should be to me.

In short, slofut; the nut tightens the hub against the driveshaft - not involving the bearings…

The outer races of both bearings are fixed to the hub carrier - and not moved by the axle nut torque. They must be fully driven into their positions. The inner races are ‘fixed’ on the hub itself and rotates with it.

The driveshaft is ridged against the hub itself to take the torque from the nut - not against the bearings. Tightening the nut just anchors the driveshaft to the hub - while the splines drives the hub.

A calibrated shim is used to adjust play, moving the inner race of the outer bearing on the hub. Ie, the ‘lip’ of the hub extends well beyond the inner race - allowing room for the appropriate shim…

xj6 85 Sov Europe (UK/NZ)

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The shim/spacer at the axle shaft is between the bearings, so tightening the axle nut brings the space between the bearings to a predetermined distance.
If by tightening the nut with the existing shim the bearings have some end play as determined by the manual, logically the inner race is where it should be?

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Thanks much for the help guys. It’s actually at zero with the original spacer so I feel pretty confident with it. First one took me a couple hours with a dial indicator and depth gauge. I’m hoping the second will not require a different spacer and I can probably do it in 45 min. Here is a good link for anyone viewing this thread in the future. Clearer diagram than my shop manual.

No, Aristides - the shim is outside the outer’s inner race. The nut torque have no bearing(!) on play…:slight_smile:

The most confusing is that the thinner the shim the greater the play…:slight_smile:

xj6 85 Sov Europe (UK/UK.


Yes my mistake, this is correct.

This is also correct and that’s what I mean by “predetermined distance”, the nut just tightens things up.

Yes, because the adjusting shim is outside the outer’s inner race.