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View Full Version : Pre-load on a front wheel bearing.



macca
11th October 2013, 06:09 PM
I had my spindles replaced 18 months ago as the tyre when off the ground had play up & down but not sideways. The play is like a loose wheel bearing. The inner race of the bearing spins on the spindle and wear some of the spindle away at the load bearing portion of it, the bottom hence the "play". As there is no load on the other surfaces it doesn't wear so doesn't move.

It has started to do it again, I have one of those bearing tightening tools from Patrol-a-part for $35.00 and took the hub off and the other bits to access the bearing pre-load ring which screws in using said tool. Tightened then backed off and problem still existed.

I took it to our mechanic today, as well as the tool. What I had done wrong was not pre-loading the bearing.

He gave me a lesson, you tighten the bearing pre-load quite firm with a power bar, then spin the wheel to seat the bearing, repeat a few times.
Then back it off and tighten by hand using the tool only, pretty much a tight as you can get it with one hand. Refit the locking plate and screws, if the screws will go in you are sweet and the wheel will spin freely, otherwise adjust until the screws will fit.

Reassemble with a smear of gasket silicon on the hub mating surfaces and your done.

I had always thought you have to back off a bearing (as in trailers) but not in this case.

Very grateful to my mechanic for showing me how to do this properly and am better prepared for out back repairs.

Hope this helps you too.

The tool........

Dhuck
11th October 2013, 08:02 PM
Yeh. Pretty much do it up firm, spin the wheel then back it off do it again a couple of times. The wheel should turn firmly but with ease if you know what I mean. The bearings that people get wrong is the swivel hub bearings. They require a little more attention. If to tight they bind and if to loose you will get a serious wobble in the steering.

Cuppa
11th October 2013, 08:12 PM
I seem to recall the seating process being mentioned for NEW bearings, but the suggestion was that this was not needed when refitting used but serviceable bearings. Any idea on what your mechanic would say to that?

Cuppa

macca
11th October 2013, 08:15 PM
Dhuck it would be good to see a how to do the swivel bearings. Add to our pool of knowledge. Thanks

macca
11th October 2013, 08:57 PM
I seem to recall the seating process being mentioned for NEW bearings, but the suggestion was that this was not needed when refitting used but serviceable bearings. Any idea on what your mechanic would say to that?

Cuppa

No I don't know Cuppa. My bearings were "loose" so needed tightening and this is how he showed me to do it.

macca
12th October 2013, 07:54 AM
Cuppa I think the idea of over tightening with a used bearing is to make sure it is fitted correctly, that is tight on the spindle and seated home on the shaft of the spindle.
What I wasn't aware of was the pre-load, the bearing has no play like the small amount when adjusting a trailer bearing.
Would make the steering better if everything is tight, he did that procedure with the used bearing yesterday so I'm guessing it is the method he uses for all re-installations.

happygu
12th October 2013, 08:14 AM
Great post Macca,

Extremely helpful for all of us...

Mic