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Front hub nut tension

Posted: 29 May 2006, 13:11
by Dubmeister
I am renewing the front discs and varoius other braking components. Can anyone advise on the method to achieve the correct hub nut tension.
Following the Haynes manual it says to tighten the nut whilst spinning the hub until it becomes difficult to turn. I tighten the nut fairly tight but the hub still seems to spin, admittedly not as free as with finger tight torque but not stiff as I was expecting.

Is it best the pull on or rock the disc so there is a minimal movement and then peen the nut or what?.

Thanks.

Posted: 29 May 2006, 14:02
by HarryMann
Don't think they meant 'till you can't spin it' they meant till you can 'just' feel some resistance to spinning it i.e. less than you are tightening it.

Which probably works out to just slightly tighter than your ad hoc method, which I would say wasn't far out... as long as everything (bearings etc) are already pulled up properly.

Hope that helps, but I haven't done a T25; this is normal method for taper bearings or angular contact balls without a spacer tube between them - which I believe the non-syncro front hub is.

Posted: 29 May 2006, 14:08
by HarryMann
Bentley says:

- tighten nut firmly to seat the bearing, at same time spinning wheel so bearing does not jam;

-- back off nut

---- wheel bearing clearance is correctly adjusted when thrust washer can be moved slightly with screwdriver (arrow in diagran) and finger pressure. Do not pry or twist screwdriver.

(diagram shows screwdriver pushing directly in (to wheel axis))

----- peen nut

------ install grease cap

Conclusion: Haynes is misleading :roll:

Posted: 29 May 2006, 19:59
by Dubmeister
Thanks for that.

I have had a few trys with it today but rain has stopped play.

To be fair to Haynes it does have the same advice about moving the thrust washer with a screwdriver (finger pressure). It's difficult to see what they mean by moving the washer. Is it movement between the face of the bearing casing and the thust washer or is it movement perpendicular to the plane of the axel axis?.

Posted: 29 May 2006, 20:06
by HarryMann
Sorry, really can't tell looking at picture, but guess that by pushing on it slightly at an angle it just about moves...

I'd set the the nut about where you were originally suggesting, what I'd call just nipping it up to take up any free-play, that's normally how its descriobed (or was so many decades ago!) - of course , as said above, once you're sure everything has been pulled up at least once and is seated well on their shoulders - hence the bit about about '... then back it off'' from Bentley.

You can always re-check the tension after a run a round the block or two r three ...

Best of British, eh? Sure iit'll be Ok, just have the odd sapre nut in the toolkit :)

Posted: 30 May 2006, 15:34
by toomanytoys
You need to do the nut up fairly firm to get the bearing seated properly, then back it off so the washer can be moved with a slight preassure, this should also mean that there should be a little play felt when you grip the wheel top and bottom and rock it..
the washer should only "slide" between the nut and the bearing inner race. it can move about a bit within the slot and the dimension of the centre hole in the washer..

Posted: 07 Jun 2006, 19:54
by Dubmeister
Thanks for that.

Have peened the hub nut up now with the thrust washer having a bit of movement.

I have other problems with brake pipes, calipers and alike and will post another message.