Rear Axle Nut Torque

[fvee62]

I had a rear axle nut come loose at PIRC at my last race of the 2022 CCS season. I have been racing and doing my own prep for many years and have never had an axle nut loosen up before. I use the geared leverage tool that attaches to the rear lug bolts and I torque the nut to 270ftlbs. I am running front & rear discs and CCS spec Yokohama A-52 tires. I referred to the factory-issued "VW Without Guesswork" booklet and the stated axle nut torque is only 217ft.lbs.
My question is - would a higher torque number help cure this situation and if so, could that possibly cause any rear axle/bearing problems?

[Onebadbug]

It's hard to get them too tight. be aware new Chinese nuts are crap, you need original ones.

[Dietmar]

If the axle nut came loose WITH the cotter pin installed, then I would look at the splines on the drum. If they are worn, then the drum moves around enough to indicate a loose nut ( finger tight) - even with the pin installed.
I'm sure that Without Guesswork also states that if you can not find the pin hole at 217, go further until you are able to locate the hole. Sometimes that will take you to 270#

Dietmar
Quixote Racing

[FVRacer21]

The drums should be checked every session. I use a “loose” cotter pin and if I see that is binding, I suspect a problem. Make sure you do not use the shim like washer. It will pound out. Make sure the inner sleeve is put on correctly and the drum should fit on the axle with no wobble.

I wish I could say all drums are equally good, but……

chrisz

[scott fairchild]

Helpful tip that looks nice too: use an AN3 bolt instead of a cotter pin.

[Hardingfv32]

[QUOTE=fvee62;650815]I... I am running front & rear discs ..../QUOTE]

The hubs for the disc conversions are steel billet. The internal splines have to be done with a broach. These hubs are made in very small runs. I could only find one shop in the US that would do such small runs ... AND... had the correct VW spline broach for our axle size.

I can imagine that the broaching machine is very old and the process getting a little out of spec. Maybe the axle splines are also a little worn. Not much you can do other than retighten/check the nut periodically. The torque you were using is just fine. Maybe lubricate the gear mechanism on the torque tool.

Brian

[DannyPip]

All good information above. This gets talked about a bunch in VW circles.

Kudos to Chris Z for pointing this out.

The washer/shim that comes in todays axle seal kits is flimsy CRAP and should be thrown away and not used. If it compresses even 0.001" the nut will be loose and your splines will start to eat themselves alive.

I re-use the old VW ones, they are hardened and will not compress.

250-300 Ft. lbs. is a great number. The factory number of 217 is simply not enough. We're way past the original design specs for side and torque loads.

[fvee62]

Thanks to everyone for all the tips - much appreciated!