Rear axle shafts

[Sunny the Model A]

Alrighty people got a good one for you. I'm currently working on my brakes on my pickup as I have been repainting my backing plates and it has been going well. however, I noticed something that alarmed me, and I would like to ask y'alls opinion on the matter. When I pulled the drums off to inspect the brakes on the rears, I noticed that the rear axle shaft on the passenger side has side to side play between the shaft and housing. I'd say about .080" in side-to-side play. backlash and in and out play all check out but the side-to-side play got my attention. I know this is a 3/4 floating axle and the axle shaft doesn't support any weight but I want to know what y'all think about this. I need to keep this truck on the road since my chevys are laid up with major issues and I need to be able to drive it. thanks for your time.

[Kurt in NJ]

With the hub off the axle moves a lot normally except in- out

[Sunny the Model A]

As long as it's not in and out it's fine? I was worried about a bearing or axle shaft breaking and the wheel falling off. since I hadn't noticed it before, maybe I just don't remember if it did that before Just so long as it stays on the car and doesn't give me any problems down the road I'm happy.

[Joe K]

Define better "side to side play." If it's movement of the shaft in the hole, then you're probably fine. If it's "in and out" - maybe not so fine.

Um. Look over Tom Endy's instructions for rebuilding the Model A rear axle.

If "in and out" it's sounding like you have "extra space" somewhere between the axle shafts. Possibly in the housing bearings, possibly in the differential carrier (which "pins" the two axles together and causes them to face the differential spider gears.)

In and out not sounding that good - how does the rear axle sound otherwise? Noise would probably be between the pinion and ring gear. But there could be a lot of free play in the differential carrier part which you never hear - except when you turn a corner.

https://www.santaanitaas.org/wp-cont...vised-2014.pdf


Joe K

[JayJay]

Sunny - +1 to Kurt. The side-to-side movement (just to be clear, I mean fore and aft relative to the frame, or up and down) you see is normal. There is no support of the axle itself at the outboard end of the axle housing, it sort of flops around out there. Not like a modern car that has a bearing carrier at the outboard end. Once you get the bearing in the hub and the hub on the shaft that should go away. If it doesn't - look for wear on the axle housing, or wear within the hub. The Red Book gives wear tolerances for both, and the suppliers have sleeves to install if either are out of spec.

[Ed in Maine]

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Last summer I rebuilt the rear axle on my cabriolet due to a chipped ring gear. I worked on it a few hours each day and it took me 2 months! Joe K has made an excellent reference to Tom Endy's rebuild paper of 2013. It is 65 pages long with excellent pictures! Part of this rebuilding process is establishing a preload on the carrier bearings in the rear end. When you put the two axle housings on the banjo, you must have enough gaskets/shims between the housing and the banjo on both sides to achieve this loading on the bearings. If too tight, you could be locking up the bearings and too light, the axle shafts would be moving in and out as you describe. As it turns out, my cabriolet required 0.025 thickness of shims to get the light loading on the bearings. Rebuilding a rear end is not for the feint hearted. I would go as far to say, "do not open up a rear axle unless there is something drastically wrong." A leak of 600W is not a good reason. In your case, if this in and out movement is slight and there is no noise, I would leave it alone.

[Bigsnapper43]

The play at the outboard end of the axel is only controlled by the grease seal in the bango housing. If it is moving as much as he says there will be a grease leak from the bango.

[rotorwrench]

The rear hub bearings are the ONLY support for the outer ends of the axle shafts. Folks have fabricated rear drum retainers that will prevent the hub from departing in the event of a shaft breaking but they were mostly made for hydraulic brake set ups. I haven't seen any for model A rear ends.

[Synchro909]

Originally Posted by Bigsnapper43

The play at the outboard end of the axel is only controlled by the grease seal in the bango housing. If it is moving as much as he says there will be a grease leak from the bango.

What about the rear wheel bearing - that big roller bearing that carries the weight of the car? With the hub locked onto the taper, everything is then held quite rigidly in place by the bearing. The seal carries NO load what so ever.
IMO, the OP will be fine to reassemble it as it is.

[Bob Bidonde]

These slides should help you.

[old31]

Bob, your ability to do great slides is amazing. Keep up the great work.

[Bob Bidonde]

Thanks Old31!