Calling all rear axle experts! Knocking noise coming from rear axle

[Bored&Stroked]

Originally Posted by Brian

I've been following this thread. You could also have wear inside the carrier where the end of the RH axle rubs. This would permit the end play you speak of and also make the noise as you go into and out of turns as the thrust is taken up/ eased off.

This could surely be true - especially on the side where the axle comes through the carrier and not through the ring gear. The answers should become quite clear once it is taken apart and all parts inspected and accurately measured with a mic.

[alchemy]

I needed a few good R&P's this spring and bought a box of them and misc parts. One of the carriers had a huge amount of wear at the inside surface that would contact the backside of the axle's gear. Like the car was always turning one direction putting a lot of load at that point as the axle was pulled out by the tire. I didn't get the axle shaft that went with it, but I bet it was worn too.

Maybe the OP's problem is the same?

[mcgarrett]

I think the last 3 replies are correct in their comments, and I believe that is exactly what is going on. Thank you for helping me zero in on the problem.

[Mart]

I had a 40 coupe that had a lot of in and out play on the RH side. Other than the play, I could not detect any problem caused by it.

Mart.

[Flathead Fever]

I have a '34 rear end apart that had excessive axle axial end play like yours has when you grab the drum and pull in and out. I thought the case was going to worn away inside from the side gear but its looks perfect. There is a specification for that end play. It's been a long time, but I think mine was around .040 using a dial indicator which was too much. I never had the rear end in a car, so I don't if it made noise or not. Back when I took it apart, I was wondering if it might clunk a little with that much play. With that much end play, the increased play between the side gear and spider gears could cause a clunk. I rebuilt the rear ends at the phone company, at least a couple hundreds of them over 30-years. The trucks were way overloaded so they blew-up rear ends all of the time.

When the spider gears get worn, they get too much play between the gears. One wheel will be ready to go but the other wheel has to rotate to take up the slack in the gears and it makes a big clunk when they finally made contact. Moving the side gear away from the spiders because of excessive endplay might do the same thing. It may not be axle moving in and out but the spider gears making the noise. With the opposite wheel on the ground, try pulling it towards you and rotating it back and forth to see how much play in the gears you have. Then push it in and see if the play goes away.

I used to take a lot of those ASE certification tests. I always thought, wouldn't it be great that if in the real world the only possibilities to the problem were either A,B,C or D.

[mcgarrett]

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Flathead Fever,
Thanks for your suggestion. I'll give your test a try...couldn't hurt to know what information that might yield.

[Flathead Fever]

If the axles' side-gear or spiders wear that would cause the excessive axial endplay. I was thinking about my '34 rear end, that it was the wear in the housing where the axle rides up against the housing. When i didn't find any sign of wear I was going to put a shim in between the axle and the case. I have hundreds of shims left over from rebuilding rear-ends at the phone company. But it did not leave the factory with that much play so installing a shim is not the answer, finding out why the play has increased is. I bet that endplay is from worn out spider gears or the axle side gears. If it's only on one side, it might be the axle gear. If you, have it on both sides it could be the spiders. And if you're as lucky as me it's probably both. And this might not even fix the problem, the noise could be something else.

If you do pull it a part, make sure to measure the thickness of the axle housings' paper gaskets with a micrometer. The dieerent thickness paper gaskets are used to setup the side bearings preload and the ring and pinion backlash.

I rebuilt at least 200 rear ends at the phone company but never an Early Ford. But I'm about to using an NOS set of 3.54 gears and one NOS axle housing.
I bought these parts at least 30 years ago for a '34 rear end I'm converting into a late model '32 with the straddle mounted pinion. I collected parts and cars for 40 years. Last thing I wanted to do was work on vehicles from 4 to 12;30 at night for 30-years and then come home and work on more car during the day. Now that I'm retired , I can start building some of these cars. A real '66 GT-350, '70 Boss 302, '33 pickup '34 pickup, chopped '32 3-windoew, '32 5-window. dad's '32 roadster, my '32 roadster project with an original chassis with 1940s era speed parts (Brookville body) The Mitchell Muffler Pickup which is a '28 pickup with a lot of early hot rod history from 1946 to 1953. A stock '29 roadster, a factory black 4-speed '64 Falcon Futura, a factory red '64 Falcon Sprint, two early Mack truck "C" cab trucks, a 200 mph Bonneville roadster with a Boss 302 motor, vintage mini bikes. go-karts Cushman Trucksters... That's a 40 year collection, no way I could afford to buy this stuff today. I'm very lucky to have bough it all back before everything got stupid expensive.



I have at least four disassembled '34 rear ends that I will choose the best pieces from. Year's ago there was man names John Deats that sold Early Ford rear end parts at the Long Beach swap meet. He found me the NOS 3.54s (nobody reproduced them at that time) and the "late model '32 torque tube and driveshaft I needed. He said too look at the case because they crack. He said its better to use a later year case. Where you press on the side bearings the later case will extend out past the bearing but it doesn't hurt a thing. I came home and looked at the '34 case I was going to use and sure enough it was cracked. So that must be really common. I had a disassembled '48 rear end so I'm using the case from it.

What else have I learned about early Ford rear ends. I had a friend named Bernie Couch that had owned is '32 roadsters since 1937. He raced it at El mirage from about 1948 to 1950. He took his '32 axle housing and swapped them from right to left That puts the spring hangers down low and lowers the back of the car. But it also screws up the radius rod mounting, and you have to weld on new brackets. The shock link ball will also be in the wrong spot. If you have a noisy rear wheel bearings with pitted axle housing races the pits will always be on the bottom side because it carries all the weight. The roller bearings probably don't even touch the top of the race and if they do its with very little pressure. By swapping the housings it moves the pits to the top and its like having new races again. You can only do that if the they are just pitted and the diameter has not worn. Thats an old-time trick for lowering the back of your '32-'34. I'm doing that on my 1940s era '32 roadster hot rod project.

When I went to knock out the axle seal from the '34 housing the seal broke and left just the outside part of the seal pressed into the axle. Now there is nothing to hit against to drive it out. Now I have to make weld up threaded tool that will thread into what left of the seal and pull it out with a slide hammer. I have other housings but I refused to be beat by a stupid seal! The next time I see a KR Wilson axle seal puller I'm buying it.

I have all this rear end rebuilding experience but none on Early Fords other than breaking a seal, its a different animal. The principles are all the same, just the axles seal replacement and the paper shims are different

We had at least 100 Dodge vans that the front pinion bearings would not last more than 20,000 miles. It was easy to just leave the right-side adjuster in the same spot, back off the left adjuster, pull out the carrier. Replace the pinion bearings and put it back together and the backlash stayed the same. The bearing are ground to a 1/10,000th accuracy so changing just the bearings in a rear end does not change the pinon setup. Just a few little pits in the pinion races made the bearing noise unbearable to listen to in those vans.

We also had Dana 60 reared ends in the 1-ton pickups. The drivers would come off the ice up in the mountains spinning the tires and when they booked up on the payment with the heavy loads they carried it grenaded the ring and pinion or broke the axles. On those you lost the setup when you installed a new carrier and ring and pinion. Those Dana's have shims under the side gears and shims and under the pinon bearings instead of treaded adjusters. I would press those bearings on and off several times changing the shims to get the correct preload, gear pattern and the backlash. I kept blowing up bearings pressing them on and off. Because I did so many Danas, I finally took a set of bearings and I honed them until they would just slip on and off by hand. I used those to setup the Dana rear ends. When I had it where I wanted it I slipped off the honed bearings and pressed on the new ones. That saved so much time and I didn't destroy any more new bearings. We bought our parts wholesale from a warehouse. You cannot believe how much markup there is on bearings and seals. We were getting Timken and BCA bearings dirt cheap. One day I had to go buy seal at the parts store that I normally stocked. I would have paid $3.00 from the warehouse, it was $22.00 from the parts store.

Its's hard to find that special yellow gear marking compound for checking the ring and pinion tooth contact pattern. I used to get it from the Chevy dealer. A guy I bought some slightly used Detroit Lockers from for my '70 Boss 302 rebuilds rear ends for a living, that's all he does. He does a lot race cars. He told me to go get a tube of yellow oil based artist paint which Hobby Lobby sells. He said in all the years he's been building rear ends he has found nothing better for leaving contact pattern. I've yet to give it a try.

[mcgarrett]

Yes, that could be true. I'm not going to be able to remove the axle and tear it down for several weeks yet. I know for sure that the knocking noise is coming from the right axle and that is where the axial play is. The drivers' side is snug and no noise. I'm going to put a dial indicator on it this weekend and try to determine exactly how much.

[Bored&Stroked]

You should be able to get the yellow gear mesh compound at Jegs:

https://www.jegs.com/i/JEGS/555/612200/10002/-1

[Brian]

My supposition comes from first hand experience. When I originally built the diff, I used all NOS/NORS parts. After some time it developed axial movement at RH axle, also a 'clunk' developed like when taking off from a standstill....turned out the NORS carrier I'd fitted was not case hardened, at least not to the degree of genuine Ford carriers, consequently it rapidly wore where rear of RH axle bears against it.
On a related note, I have also noticed [some?] NORS axles have insufficient hardening at the side gear end of axle, and those gears rapidly wear.
As I result of these observations, I now only ever run genuine Ford parts.