Looking For Torque for Front Axle Clamp Nut

[Hodence]

Hi all!

I just completed a spindle swap on my ‘72 bay window Westy. With these new spindles I installed fresh bearings and races on my hub. Put it all together, bled my new disc brakes and went on my merry way… for about a week. Then I noticed when my passenger side wheel hit bumps in the road there was a clunk. I drove with the clunk for about a day (maybe 4 miles, not much) before deciding it was in fact suspension and not just my passenger seat moving around. I’ve taken a look and all the spindle ball joint hardware seems snug, as with the caliper hardware and brake lines and everything. I believe that my axle clamp nut (google “axle clamp nut” if you’re unfamiliar with what I’m talking about) is not tight enough, causing the bearings to move on the spindle when hitting bumps. Since you can only fit a crescent wrench on this piece of hardware, I snugged it to “I can’t loosen it with my fingers” and not much more. In my research there’s multiple different measurements for how tight to go. Bentleys says “no more than 9ft-lb” but I believe that’s the hex screw on the clamp nut.

All this is to say… how tight should my axle clamp nut be? I saw a spec that said “as tight as reasonably possible and then back off about 60 degrees. Is that right? Thanks for taking the time to read my post

[busdaddy]

Tight, then backed off a 1/4(ish) turn is correct, it has to have the tinyiest amount of play to allow grease between the bearing parts.

Hopefully you didn't damage your bearings by driving with it tightened up.
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[aeromech]

Raise the wheel off the ground
Spin the tire while tightening the nut
Once tight back it off a bit
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[Hodence]

Alright. Thanks guys.

I also hope I didn’t mess up my bearings or races. If I run into any more problems I’ll update this thread.

[Abscate]

You can’t mix races.

Wait, old school of thought.

You can’t mix bearing races.

Wait, still bad.

You can’t mix when bearingraces

Got it.

( Stolen from John Muir’s book)
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[bsairhead]

Is a feeler gauge spec not listed somewhere?

[busdaddy]

[Wildthings]

I like to use the Vanagon bearing adjustment technique which is to test the movement of the washer as you tighten the nut. Right at the point where the washer becomes harder to move is the point to aim for. Another technique is to set the bearing preload slightly on the high side and then drive for ten'ish miles at highway speeds with minimal use of the brakes. At 10 miles pull over and check the heat of the hub in the grease cap area, it should be only slightly above ambient. If the temp is too high loosen the nut by a 1/64 - 1/32nd of a turn and drive another ten miles and check the temperature again. When done correctly the bearing will generate little heat and be as tight as reasonable possible to give the best handling.

[kreemoweet]

The clamp nut has ZERO torque against the bearings/washer. It is meant to be "loose", meaning to leave .001-.005 in. axial play.

If you mean the socket-head screw on the clamp nut, torque is 11-14 ft-lb.

This is all in your Bentley manual.

The warning about not exceeding 9.5 ft-lbs does indeed apply to the torque of the nut against the bearings.
I don't think that's much more than hand-tight.
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[Abscate]

You can set a roller bearing preset load correctly with hand strength on that nut. If you turn the wheel while you crank it down, you can feel the play disappear as it loads, and you will find the difference between no play and acceptable play will be something like one flat on the hex, or about 60 degrees of rotation

The bearing play has no impact on handling - 0.1mm of bearing motion is negligble compared to suspension and chassis flex.
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[SGKent]

why reinvent the wheel. Just follow the factory specs and you won't be wrong.

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[timvw7476]

Had no idea VW made that front wheel bearing service so technical.
One thing's for sure, when you put in new two-piece bearings, it's reasonable to drive it forty seconds to a minute, around the block say, & re-check / re-settle those front locknuts. Every one I ever touched was more than nine ft/lbs. But I always seemed to be the only guy who looked. : l
Nine on the allen bolt? Okay.

[aeromech]

[aeromech]

Delete double post
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Wildthings]

[Wildthings]

[raygreenwood]

[SGKent]

of course no one considers that the mechanic is usually working on a car that has been sitting, and is cool. Out on the road the brakes are going to heat up the hub more than the spindle. Its mass is greater also since any heat in it is going to conduct to the rest of the spindle. Since it is pinned between two bearings when it heats up, it will likely expand, using up that play. In 750,000 miles on my 1971 following the factory setting, I never once had a bearing go bad and when I would replace them every 200,000 miles or so it was because of best practices and not because one was coloring.

on the race car we would tighten the bearings down until they were snug and drag was felt while spinning the wheel, then loosen until the washer could be pushed with a screw driver tip without much force. Never had one fail that way either.
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[raygreenwood]

[Abscate]

I can feel that extra 240 microns of steering slip every time I pull into the grocery store to get tampons. I better get the tools out this weekend
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