Oooo, I need mechanical advice

notjustair · Apr 4, 2017

I'm in a pickle. These pictures are the rear axle of the old chore truck - the '35 Chevy. I had always thought the clunk when backing up was the
yoke in the torque tube needing shimmed. It turns out it was this brake drum rotating on the axle. She's obviously been doing this for many
years. It has wollered out the keyway on the axle and the brake drum as well as worn it rather angled.

Keep in mind we're talking parts non existent or used.

Should I true up the oversized keyways and find bigger keystock? Should I weld them up and recut the keyway? The drum is cracked along the
outside rim as you can see but it only extends about a quarter inch. I think it is from my uncle putting torque to it to try and keep it from rocking.
He had four washers under the nut and a 16 penny nail as a pin. I'm pretty sure that will tack up just fine.

I'm leaning toward going oversized with it. Something about welding on that axle doesn't sound right to me. I know an old mechanical brake
drum for that year is rare as hen's teeth. I can't imagine what finding an axle would be like.

Janicholson · Apr 4, 2017

Have a refreshed keyway broached in the drum hub. Ignore the crack, not germane. Mill the keyway in the axle (remove to do). If it is bell mouthed more than .005, I would shim the difference with tapered shim stock. Clean it with a wire brush and fit the shim stock to make it as true as possible. ues epoxy to glue the shims onto the axle wrap in stretched black vinyl tape to cure. Mount it and be happy. I would probably chase the axle threads and use a new heavy nut. Jim
tapered shim stock.

WellWorn · Apr 4, 2017

NotJust, I admit you have a conundrum. To do it "right", you'd source an axle and drum. To make it work, there are a number of options.

I've heard that "liquid steel" (JB Weld?) actually works for such repairs. I've use JB for some stuff, but I'm not convinced it's as strong as steel, and I don't see it holding up in that application.

I know a metal worker who could weld the axle and drum, re-cut the keyways and properly heat treat the axle and stress relieve the drum, but I wouldn't trust that sort of repair to just anyone, especially one without a proven track record.

Probably what I'd do is have the keyways re-cut for an oversize key. It won't be "original", but obviously the original design has some to be desired.

glennster · Apr 4, 2017

there is a company in morton grove illinois called strange enginneering. the do custom axles for drag racing. we have used them and they do excellent work and are reasonable. they could build you a new axle.

David G · Apr 4, 2017

As stated on Smokey and the Bandit, "what do the X@$#$# Germans have do with this"?

Tramway Guy · Apr 4, 2017

You could also mill the axle keyway wider and have a step key made to work with a new keyway in the hub.

37chief · Apr 4, 2017

A problem all right. Since it has been slopping around I would think the drum hole is worn oversize. And the axle is worn under size some, A new key in both parts will work for a while. I am sure there are used parts some where, it's just finding them. For a temp repair if it were mine, I would weld the key to the axle, and carefully grind down the weld until the drum slides back on. Then how long has it been loose, and how old are you. It might go for a long time for a farm truck.Stan

onefarmer · Apr 4, 2017

I have a machine shop local that would weld up that shaft regrind it to the correct or oversize size and recut the keyway. I'm not sure about the drum but they probably could weld it up and rebore correct or some over and recut the key to match.

leroy in ne · Apr 4, 2017

might want to check out Loctite products site in particular the section called metal rebuilding and shaft repair

notjustair · Apr 4, 2017

Funny you should mention that. My first thought was to buy a new key and weld it to the axle closing in the wollered out keyway. Then grind it down smooth up to the key and put the hub back on.

Funny side note - this truck has always been known as Leapin' Lena but no one knew how it got that name. My mom remembers driving it to the elevator with wheat and it was Leapin' Lena when she was young. She always said she sure could jump. She also said that old 207 was nearly imposssible to get started after it had ridden the sling up and flooded the engine. I'm betting that this has been a problem for many decades that was solved by putting another washer on the axle and tightening it down. When she loosened up she started leapin' again. The axle is cone shaped much like a little Ford tractor so it would pinch it tight for a while until it wore a little more off the key.

It doesn't do anything but check pastures, run to town for parts, and haul some hay and wood. There aren't any 7000 pound loads anymore for her. I'll bet a welded key would hold up.

ss55 · Apr 4, 2017

I would mill new key ways 180 degrees from the old ones in both the axle and the brake drum. That would move the stress away from the crack in the drum and would not weaken the drum like an oversize key way would.

Steve@Advance · Apr 4, 2017

I vote for oversizing the existing keyway to minimum clean up in both the axle and hub.

Then make a custom key to fit.

Do you think that was originally a tapered fit? If so, look into taking some off the inside length of the hub to allow the drum to go further on the shaft to tighten up the taper. In the picture it appears to be straight, or used to be straight. If it was originally tapered, there will be several degrees of taper. The taper you are seeing may be wear. If worn from running loose, not much you can do but get the key fitting best as possible, clean up all the rust and grease, go back with some Locktite or epoxy to try to hold it best as possible. Be sure the nut, threads, and washer are in good shape and will tighten without bottoming out, may need a thicker washer.

I would not weld on the axle. The heat could change the temper, cause it to break under load.

How is the other side? Does it need the same before it gets any worse?

Dr. Walt · Apr 5, 2017

I think it might be time to upgrade and put a newer rear end in that old girl, like 50 years newer. Easier to find in a Salvage Yard and you'd also have better parts availability.

:>)

UncleTom · Apr 5, 2017

I would check and see if it is covered under waranty.

caterpillar guy · Apr 5, 2017

All that machining for another failed axle again just put a newer axle in and drive it. Might actually convert to hydraulic brakes so they work for more than one hard stop without having to adjust ever time you have to use them hard.

BarnyardEngineering · Apr 5, 2017

You'd be amazed what you can achieve with a good file, some elbow grease, and persistence. These guys that want you to pay for a 10 hours of machine shop work on an 82 year old truck are nuts. If you were restoring it that would be one thing, but you're just trying to keep it running and driving without spending a lot of money.

Clean up the keyways with a file, grind yourself a custom oversize key, and put it back together. Maybe cut up an old beer can for a shim between the drum and the shaft if it's wore that bad that it won't suck back on the taper otherwise. It'll outlast you.

Mike M · Apr 5, 2017

That outside edge of the hub could be machined and a sleeve made to go over it as a press fit may help contain that crack ? I have had worn shafts built back up by a spray weld process. Seems to work good.

4wdtom · Apr 5, 2017

That is a tough looking problem. I don't see any taper on the axle and without taper it would be hard to get everything tight enough to not move I think. There is a LOT of torque going through that axle to hub joint. ANY movement will allow it to happen again. The key will have to be a tight fit and the hub to axle a tight, (press) fit I think for it to have any hope of lasting. Whether you get new used parts or fix the old ones I think this applies. If the hub is cast iron it may be difficult to fix wit welding and I an to sure you want to be welding on the axle. Using the old parts I would widen out the key, keeping it on the same side of the axle, you don't want a big "hole" in the axle opposite a new key I don't think. Possibly the hub could be bored out and a bushing with a new keyway welded in. You have a tough one here. I hope you can get a good repair.

Crazy Horse · Apr 5, 2017

I see in a later comment that the poster said it was used "on the road" to town, etc. And someone else mentioned putting in a newer rear end from a salvage yard. That's the best solution and likely far cheaper than getting someone to fix the problem (if that is even possible) in the old rear end. If a guy can do the repair all himself, that's one thing. Paying someone else to do it, especially machine shops, etc ..... not that's a different situation.

sms · Apr 5, 2017

Google stovebolt and you should see s couple sites dedicated to old Chevy trucks. Look for parts or ask where to find another rear or good axle. Good luck.

BushogPapa · Apr 5, 2017

You must like leisurely trips to town....!!

Our '51 Chevy 1 ton PU was best run under 45 mph..remember it had a NON-Drilled Crank...that didn't change until '52.

Oh, we hauled many 100 bu loads to the Mill..that 216 would never miss a beat and top the hill at 13 MPH and still in high gear..

If ya dropped a gear, it would only be going slower yet..!!

If I was changing rear ends, I believe I would look for a 2-speed rear end for it..

Looks as if (maybe) it has been a day or two since that drum has been off...!!!

If you are not careful, some of that dust may fall off before ya get the drum back on...!!!

Paul from MI · Apr 5, 2017

I don't know if you have enough material in the hub, but you could look into a heavy duty taper lock bushing. I have used them on machine repairs where no key would remain tight and had good success. No key is required, the friction of the clamp is enough to hold them tight. Google Mcmaster-carr and "heavy duty screw clamp bushings". There are several styles.

DGinVT · Apr 5, 2017

I had a very badly worn keyway on the right rear axle on a 1950 VAV Case tractor. Not wanting to spend too much money, I carefully filed out the existing keyway, and hand filed to a slightly oversized key and drove it home and never had another problem with it. No cost except for my time which I did not count. Looking back at the job the wheel hub and axle never bothered again.

CenTex Farmall · Apr 5, 2017

My vote

CenTex Farmall · Apr 5, 2017

Bonus points for Smokey and the Bandit reference.

Married2Allis · Apr 6, 2017

With more trouble than just a worn keyway, I'd go with a replacement axle. Machine work is $$$ .

RedMF40 · Apr 6, 2017

I'd suggest axle replacement as some others have mentioned. Get measurement drum-to-drum, see what'll fit. Might even get into town a little faster

Oooo, I need mechanical advice

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