Rear Axle Nut Torque Spec

[JC85]

Does anyone know the torque spec for the rear axle nut in a loop frame Eldo? Greg Bender's site says 101-107 ft lbs, but my wheel was seizing up, before I got there. Seems like too much.

[Tom H]

To start with, if your wheel is seizing up when you tighten the axle nut, you might want to check your bearings.

Lets see, torque setting. With a normal 1/2" drive ratchet, how hard can you pull. That should be about right. Unless your a superhero or the like

Tom

[guzzisteve]

I use a 1/2in breaker bar and lift up till I fart (from my friend Pete). Hey, there is a lock bolt on the swingarm rear & it's not going anywhere.

[JC85]

I just replaced one of the bearings, which is why I'm reassembling it, now. Both bearings are good to go. Maybe I need to add another spacer on the new bearing?

[Tom H]

You do know how to shim the bearings, right?

Tom

[Dave Swanson]

I just replaced one of the bearings, which is why I'm reassembling it, now. Both bearings are good to go. Maybe I need to add another spacer on the new bearing?

If you replaced the Timken bearings you will need to shim for pre-load.  Anytime you change tapered roller bearings on a wheel you will need to re-shim because the over all dimension changes a bit.  Looks like you need to start by taking shim out.  If you need shims, McMaster Carr is a great source.

[JC85]

If you replaced the Timken bearings you will need to shim for pre-load.  Anytime you change tapered roller bearings on a wheel you will need to re-shim because the over all dimension changes a bit.  Looks like you need to start by taking shim out.  If you need shims, McMaster Carr is a great source.

Reshimming was my thought, but I want to double check the torque spec, as well. Taking them out, though? I would have thought adding, not removing would be the way to go.

[Dave Swanson]

Reshimming was my thought, but I want to double check the torque spec, as well. Taking them out, though? I would have thought adding, not removing would be the way to go.

Sorry,  you are right.  You will have to add.  Right now you have too much pre-load.  Adding shim will reduce it.  You will have to keep adding until you hit the sweet spot.  You will be able to tell when it is just right. 

[Tom H]

This is a good but short version on how to do it:

http://www.thisoldtractor.com/moto_guzzi_loopframe_wheel_bearing_adjustment_shimming_set_up.html

You don't "NEED" to torque to the spec while shimming, just get it very tight. You will know when the free play is right, too little and you can't turn the axle or it feels like it's binding. Too much and you can wiggle the axle side to side. I would error on the side of "slightly" loose if I had to chose one or the other.

Tom

[moto-uno]

  If you have a fastener shop near by , pick yourself up a foot of 3/4" threaded rod and a couple of nuts , you
should be able to set the freeplay without going through the re&re so many times .  Peter

[JC85]

I use a 1/2in breaker bar and lift up till I fart (from my friend Pete). Hey, there is a lock bolt on the swingarm rear & it's not going anywhere.

If you crap your pants, does that mean you over torqued it? 

[Kiwi_Roy]

If you crap your pants, does that mean you over torqued it? 

Depends

[motorcop]

The torque spec is 100-Nm or 73.76 lb-ft

[JC85]

Depends

Well played.

[Antietam Classic Cycle]

Tighten it to whatever torque that you can undo on the side of the road with whatever tools you carry. For me that figure works out to about 70 couple ft. lbs.

[n3303j]

Old BMW /2 used the same taper roller bearing setup  (as does older Ural).
In both cases 25 ft/lb is way more than enough to retain the axle and keep the bearing stack properly clamped.
Proper bearing shimming can not be overstressed. Too tight and you will destroy the bearings and be a hazard to yourself. True 0.000 inch to 0.001 preload on the stack and the bearings (if uncontaminated) will outlast you.
I assume the published axle nut torque number was determined by the fastener material and dimensions, not by the requirements of the application.
Axles don't fall out. They are under a radial load. It takes a thrust load to dislodge them.
Tool kit wrenches are about 6 inches long. 50 pounds on the end of that wrench will give you about 25 ft/lb torque. Plenty good enough for the application.

[wirespokes]

I agree with the 25 footpound figure, though I've never measured precisely what I set it at. All that's really needed is enough to keep the nut from falling off. And as has been already stated, the axle's clamped so it's not falling off.

Makes sense to me the 100+ fp spec is for the size of fastener - just a generic figure.

Tapered rollers need a slight bit of preload, but will do fine at zero. Free play isn't good for them. In setting front wheel bearings on older cars (with the same bearings) the nut is tightened until the washer (under the nut) could be just slid side to side - not easily, but it would move. Harley's (from what I hear) spec zero preload. BMWs spec something like 8 or 10 lbs preload.

Don't get anal about getting the torque exactly right - there's quite a bit of leeway. The point is, don't run them loose or overly tight.

Tapered roller bearings will outlast the bike if kept clean and lubed and run with a slight bit of preload.