help asap please need info for rear hub assembly

[McFred]

Going to take the car to Circuit of the Amiercas this weekend.

Vids or it didn't happen! Or at least a thread of the experience please. I might have another excuse to go to Austin if there's an affordable track day there too.

[AdmiralMubutu]

Hi all, I know this is an older thread, but the rear hub assembly is still causing me some issues and I'd like to know if anyone came up with a solution. When i bought my Atom in March (Brammo Atom 2, #000050), it needed a left rear wheel bearing. Thanks to Terry's meticulous and abundant inventory, and Maniac729 being a very nice guy, I replaced BOTH rear bearings, using the newer hardened spacers. So yesterday I go the track, dutifully bringing along my torque wrench and 24/30mm sockets so I can retorque the lugs and axle nut after each session, as has been suggested by several posters. With R888 tires, and fairly short sessions, I was finding that the left rear axle nut kept coming loose (the same corner as the original problem I had), by as much as a full turn after one extended session. That introduces a lot of play into the rear wheel, and causes what has to be a dangerous condition as the car wanders all over the road and requires constant steering corrections to stay straight. Has anyone come up with a solution to prevent the axle nuts from backing off?? My local mechanic suggested possibly drilling a hole through the axle bolt and installing a castle nut and pin, but the bolt barely extends beyond the center hole of the wheel so fitting the pin might be difficult. Red Loctite maybe? I'm heading back to track next month and want to address this beforehand. Any suggestions greatly appreciated.

[Terry Kennedy]

Has anyone come up with a solution to prevent the axle nuts from backing off?? My local mechanic suggested possibly drilling a hole through the axle bolt and installing a castle nut and pin, but the bolt barely extends beyond the center hole of the wheel so fitting the pin might be difficult. Red Loctite maybe? I'm heading back to track next month and want to address this beforehand. Any suggestions greatly appreciated.

It shouldn't be doing that. Either there's some contamination on the driveshaft / nut threads that is causing the torque setting to be incorrect (did any of the bearing grease from the old bearing get on the threads?) or the previous owner's not addressing the bearing issue caused wear to something (threads?) that is making it impossible to get a good torque set. Let's see what other people running the stock rear uprights have to say.

[bolus]

possible option

http://arielatomchat.com/forums/thread69.html

[MadMaxAtom]

You need to make 100% sure that the inner axle face of the outer CV joint is properly seating on the correct hardened spacer.The inner spacer has a recess cut into it to accept the radius of the inner stub axle mounting surface.The inner axle face has a slight bevel to it,and if the spacer is seating up against that surface,as in it is installed backwards,instead of the FLAT part of the stub axle,you will be able to torque the axle nut to specs,however,as soon as you load that assembly,the small contact area causes the assembly to distort,enough to need to be retorqued again and again. It is very subtle,but unless it is correct,it won't hold the torque setting.

Inner CV stub axle radius…
CIMG4505.jpg

Inner spacer with relief cut for axle radius..

CIMG4506.jpg

Properly seated inner spacer…

CIMG4507.jpg


Improperly seated inner spacer (notice .010" gap)…

CIMG4508.jpg


If you do have the hardened washers properly installed,then the only other way for play to be introduced would be the bearing wearing.
I ran the stock uprights for many many miles on track,with very wide,sticky tires..with the hardened spacers and never had a problem. If you feel the nuts are actually coming unwound,I would mark them with a dab of white paint to verify it..but I doubt they are..

I found two of my brammo Atoms had the inner stub axle spacers installed backwards from the 'factory' so don't assume the way it came apart is the correct way it should go together.

[AdmiralMubutu]

You need to make 100% sure that the inner axle face of the outer CV joint is properly seating on the correct hardened spacer.The inner spacer has a recess cut into it to accept the radius of the inner stub axle mounting surface.The inner axle face has a slight bevel to it,and if the spacer is seating up against that surface,as in it is installed backwards,instead of the FLAT part of the stub axle,you will be able to torque the axle nut to specs,however,as soon as you load that assembly,the small contact area causes the assembly to distort,enough to need to be retorqued again and again. It is very subtle,but unless it is correct,it won't hold the torque setting.

If you do have the hardened washers properly installed,then the only other way for play to be introduced would be the bearing wearing.
I ran the stock uprights for many many miles on track,with very wide,sticky tires..with the hardened spacers and never had a problem. If you feel the nuts are actually coming unwound,I would mark them with a dab of white paint to verify it..but I doubt they are..

I found two of my brammo Atoms had the inner stub axle spacers installed backwards from the 'factory' so don't assume the way it came apart is the correct way it should go together.

Thanks all, I will investigate. I'm gonna start by marking the nut and axle to see if it's actually moving.

[Positron]

I'd be surprised if the nut is actually backing off. Usual suspect is crushing the washer creating the gap. But good to put witness marks as standard procedure.

Were the washers you got from Terry the ones we group bought some time back? And they must have a relieving radius on the inner radius to clear the shaft opposing radius.

If the nut is indeed backing off I think we posted the NAPA axle nut part number somewhere around here on Bolus' parts list. Standard axle nut. Terry probably knows which axle. He's like the Atom Sheldon.

[AdmiralMubutu]

I'd be surprised if the nut is actually backing off. Usual suspect is crushing the washer creating the gap. But good to put witness marks as standard procedure.

Were the washers you got from Terry the ones we group bought some time back? And they must have a relieving radius on the inner radius to clear the shaft opposing radius.

If the nut is indeed backing off I think we posted the NAPA axle nut part number somewhere around here on Bolus' parts list. Standard axle nut. Terry probably knows which axle. He's like the Atom Sheldon.

Yes, I believe the washers might have been from the batch people got at Atom Fest in 2009? at VIR? My mechanic is reasonably certain he installed the inner spacers with the recess facing inward. He actually noticed the radius on the axle shaft and realized that they would only fit correctly that way.

[Terry Kennedy]

Yes, I believe the washers might have been from the batch people got at Atom Fest in 2009? at VIR?

That was the source for the new washers I passed along to the buyer of my car. At the time they left here, I believe the old front washers and a set of new rear washers were in a ziplock bag. TMI changed the fronts on my car at AtomFest 2009. I had them give me the new rear ones (they sold them as a set for all 4 corners), since I already had the Unique Fabricating rear uprights on my car at that point and didn't need their new rear ones installed. The old rear washers from my car were boxed in with the old hubs/uprights (I saved every part that came off the car).

[Positron]

The originals and if not hardened enough would actually crush under hard use giving the illusion of nut backing off when it was actually additional rotation to take it up.

We had some made super hard and the proper chamfer relief and it was solved.