strange noise from the rear axle

hull 433 · Post by **hull 433** » Thu Jul 21, 2022 9:31 pm

I'm redoing the rear wheels on my '15 and heard a strange noise..

When I jacked up the left rear wheel, it rotated freely except for a "thump" every rotation along with a pause in the motion. The hogshead is off and the parking brake rods are disconnected. I don't remember this for the right rear wheel, but I wasn't checking for that when I removed it.

Is this something normal, or is it something else? I have visions of thrust washers but am not sure.

Post by **TWrenn** » Thu Jul 21, 2022 9:45 pm

If you haven't already, grab the top and bottom of the wheel and yank firmly on it while it's jacked up..if it moves even 1/8 of an inch "outward" odds are the thrust washer is going bad or is already junk. That's just for starters. Other things may cause this noise.

Post by **John kuehn** » Fri Jul 22, 2022 8:45 am

Has the differential ever been apart since you’ve had it or before? It may be time to go through it. An inside clunk or noise means it’s time.

pron022020 · Post by **pron022020** » Fri Jul 22, 2022 9:24 am

Mine did the same thing. I think it was the brake shoe on one side where the lining had separated and was flapping in the wind. I still replaced the thrust washers inside.

Norman Kling · Post by **Norman Kling** » Fri Jul 22, 2022 10:17 am

If you have only the left wheel up and the right one is on the ground with the hogs head off you would be turning the engine because the clutch does not operate with the hogs head off. So the thump could be anywhere between the wheel and the front of the crankshaft. If the head and spark plugs are still in place, the pause could be caused by the compression of the engine. The thump could be any slack from the universal joint to the differential. If you lift the right wheel with both wheels off the ground, you would be using the differential and one wheel would turn one direction while the other wheel turned the opposite way. If it still does the same thing, i would suspect the differential.
Norm

Post by **Steve Jelf** » Fri Jul 22, 2022 12:56 pm

If you don't know for a fact that your rear axle doesn't contain old Babbitt thrust washers, you have to open it up and find out, whether that's the source of your thunk or not. Chances are, it is.

If this is your first time you will spend more than a day on it. Don't be intimidated. It ain't rocket surgery. Even I have done it. Get the MTFCA Axle book and follow the instructions.

https://dauntlessgeezer.com/DG79.html

While you're in there, new inner seals are probably a good idea.
Use this when you put them in:

Post by **John.Zibell** » Fri Jul 22, 2022 1:32 pm

Steve Jelf wrote: ↑
Fri Jul 22, 2022 12:56 pm
If you don't know for a fact that your rear axle doesn't contain old Babbitt thrust washers, you have to open it up and find out, whether that's the source of your thunk or not. Chances are, it is.

If this is your first time you will spend more than a day on it. Don't be intimidated. It ain't rocket surgery. Even I have done it. Get the MTFCA Axle book and follow the instructions.

https://dauntlessgeezer.com/DG79.html

While you're in there, new inner seals are probably a good idea.
Use this when you put them in:
IMG_0406 copy.JPG

Steve, that product is great for sealing the axle halves, and for the spool to rear end. However we have found that good old ultra black seems to work better at sealing the modern inner seal to the axle half as it has better adhesive properties.

hull 433 · Post by **hull 433** » Fri Jul 22, 2022 2:41 pm

Thanks for the ideas, I'll put them to work.

Tim, the wheels are off at Calimer's but I'll test the axles this afternoon for outward play. I'll put the hub nut on securely and see what happens.

John, I don't know if the differential has been opened recently. The car was in the process of re-restoration when its owner passed, and that is the condition I received it in. The car arrived to me drained of oil and (mostly) grease, which I'm replenishing as I go through the car. I haven't been in the differential yet, or how much was done on the re-restoration. I'm told it was a good driving car and the engine was rebuilt with aluminum pistons.

Norman, I've been quarter-cranking the engine periodically to look for debris in the transmission (found a loose washer, for example) and I'll test that today with a full turn or two to see if I can replicate the same clunk effect from the rear axle. I'll also check the rear axles to see how they move. The head and plugs are in, manifolds are off since the hogshead is off.

Steve, thanks for the link to the sealer and idea about the seals. I haven't opened a differential before, but then there are a lot of things I haven't done before, and it's been a blast to do. Never thought a Holley G would be sitting on my desk. Got the new front tires on in fifteen minutes, felt pretty proud for a first time.

John, I have a tube of Ultra Black, used it to seal the gasket around the U Joint, keeping the rest for the hogshead.

Thanks!

Post by **TXGOAT2** » Fri Jul 22, 2022 2:49 pm

If your car was stored with the rear axle drained of grease, it's possible the ring gear rusted from condensation. Just a little rust will make a "tight spot" as the ring gear rotates. Rust tends to occur at the part of the ring gear that is uppermost.

Post by **TXGOAT2** » Fri Jul 22, 2022 2:50 pm

If you can fish around in the bottom of the axle housing with a piece of wire and come up with a gray material, it suggests the presence of babbit (or pot metal) thrust washers.

Post by **speedytinc** » Fri Jul 22, 2022 3:49 pm

One of your comments about "U joint gasket" Has me thinking I need to tell you there is no gasket between the back of the 4th main & the drive shaft flange. Common mistake that adds unnecessary slop to the "ball joint". You can use a little ultra, but that area Isnt practical to seal. There is a gasket between the 4th main & the hogs head.

hull 433 · Post by **hull 433** » Fri Jul 22, 2022 9:58 pm

Thanks for all the suggestions and info. I really appreciate it.

I tested the rear axles today as suggested. The left rear axle was firm with no in or out play. The right rear axle could push in and out by between 1/16 to maybe 1/8". I'll measure it more securely this weekend. I don't recall getting the same thunking noise, or feeling a pause, but then it's different rotating a wheel as opposed to a bare axle. I cranked the engine over and both axles rotated. The engine chuffed as expected.

I'll fish around the differential with wire to see what's down there. A friend suggested looping the end 1/8 to see if it picks anything up. I'll check for rust on the ring gear as well; the car was in two wet environments in the past.

I meant to say the U joint gasket, where it bolts to the ball cap. The hogshead is off, so it's not bolted at the moment.

Thanks!

Post by **John.Zibell** » Sat Jul 23, 2022 9:58 am

With that much play I'd recommend taking it apart and checking. There shouldn't be any movement if everything is correct. May be time for new thrust washer(s). Or it may be as simple as needing additional spacers between the axle ends in the differential. Also as stated earlier, no gasket after the 4th main. The collar needs to be right against the fourth main to keep the ball tight.

RGould1910 · Post by **RGould1910** » Sun Jul 24, 2022 11:30 am

A little side to side play could also be clearance between the differential spider gears and axle gears or a loose axle gear. If it were mine, I'd remove the rear end and open it up.

Scott_Conger · Post by **Scott_Conger** » Mon Jul 25, 2022 6:04 pm

If ever there was a time to invest in an endoscope attachment for your Android, this is it. Once purchased, it can provide no end to information that is otherwise labor-intensive to verify on numerous items on a "T".

Post by **Jerry VanOoteghem** » Tue Jul 26, 2022 12:11 pm

It doesn't matter what we think or what we guess is wrong. The fact is, it's doing something abnormal, at least by your description, and no amount of supposition will change that. Even if you had x-ray vision and could easily spot the trouble, the end result is still the same... it needs to come apart. I know, it's always hard for me to accept that reality too, when it's my own car. But it's somehow much easier for me to point it out to you

Post by **John kuehn** » Tue Jul 26, 2022 2:30 pm

This is a sooner or “not much” later situation. Sort of like a T getting hot and everything has been tried to fix it EXCEPT replacing the radiator which seems to look good that happens to be an original.

Post by **TXGOAT2** » Tue Jul 26, 2022 3:23 pm

Looking good may not equal functioning well. I used to get tires from an old junkyard. I'd pick the good looking ones. Most of them were WWII era tires with "vulcanized" repairs or unrepaired breaks in the fabric. They would fail quickly, sometimes spectactularly. I learned to pick the tires with "good live rubber" and the tread well worn. Most of these would run a few hundred miles.

Scott_Conger · Post by **Scott_Conger** » Tue Jul 26, 2022 4:03 pm

a "thump" every 360 degree rotation of a tire/wheel (while renewing wheels) may very well be as innocuous as a wheel going on a "little too far" onto the axle and one of the (new?) bolts being too long and hitting the spring perch nut. That would be a very easy discovery (if you were looking for it), along with a very easy fix.

Yes, rear ends can be problematic, but not every "bump" need be a pre-disaster nor a mandatory cause to tear down things simply out of ignorance or fear.

there's this thing called "diagnosis" and that is what's called for here. My prior advice regarding an endoscope would be valuable to that end if investigation leads to it being internal (and I've read nothing here yet which drives me to that being certain).

Post by **Steve Jelf** » Tue Jul 26, 2022 4:10 pm

Just ignore the noise and keep driving.

Never mind the bearings, take a look at those bolt heads.

You might not get killed.

Post by **George House** » Tue Jul 26, 2022 4:23 pm

Scott, I have an endoscopy and colonoscopy scheduled next week. I can see how one procedure impacts my rear end but the Original Poster is concerned about his rear axle. How does one affect the other ?

Post by **Jerry VanOoteghem** » Tue Jul 26, 2022 4:38 pm

I'd start by removing the right side hub, where you heard the thump. Look for rub marks. My advice above about disassembling things wasn't meant to suggest jumping into a total tear down, but more of a step-by-step approach.

Scott_Conger · Post by **Scott_Conger** » Tue Jul 26, 2022 5:20 pm

Steve, I absolutely NEVER said to ignore the noise!

Post by **JTT3** » Wed Jul 27, 2022 10:54 am

George, if I were you I’d make sure they use a different endoscope for each procedure or at least do the endoscopy first ha, I never did get that taste out of my mouth.

John Heaman · Post by **John Heaman** » Wed Jul 27, 2022 12:06 pm

Could be worse!

Pep C Strebeck · Post by **Pep C Strebeck** » Wed Jul 27, 2022 2:07 pm

John Heaman wrote: ↑
Wed Jul 27, 2022 12:06 pm
Could be worse!

4A13C22A-E731-48F3-9CED-603A061B8E5F.jpeg

As many times as I have seen the photo above, I am always perplexed by the complete lack of any gear oil.

: broken axle.jpg (22.63 KiB) Viewed 4979 times

Post by **JTT3** » Wed Jul 27, 2022 2:09 pm

Joseph more like gear grease/oil

hull 433 · Post by **hull 433** » Wed Jul 27, 2022 2:19 pm

That poor car! Haven't seen anything like that before.

Thanks for the ideas and suggestion, much appreciated. I've been looking at endoscopes for iOS and will report back. I haven't had a chance to go into the differential yet but will do.

This is my first car. It was in the middle of re-restoration when it's former owner passed and it came to me, so most of the work is putting it back together. Two days ago I put in the bands and now I'm practicing fitting the hogshead. The axle issue showed up when I removed the rear wheels for re-wooding.

It definitely looks like I'll be opening up the rear axle. The bolts holding the wheel to the brake drum were actually too short, not even going fully through the nuts. There is some wear on the bolt holding the right hand brake shoe on. I'll check the left. Doesn't remove the axle play issue though.

It sounds like the most workable plan is to finish the rest of the car before removing the rear axle. This will floor space and let me concentrate completely on the axle when the time comes. Does that sound like a workable plan?

Norman Kling · Post by **Norman Kling** » Wed Jul 27, 2022 4:18 pm

The bolts should be just about one thread beyond the nuts and then peened down so the nut won't come off. They might have been the correct length but not peened so the nuts began to loosen. That could be the only problem causing the drum to move toward the backing plate and become worn. However it could also have been caused by wear on the thrust washers between the inside of the axle housing and the differential carrier. Note wear on the washers at one end of the axle will pull in the axle on the opposite side of the assembly.. This type of wear could also be caused if the nut at the end of the axle is loose causing movement between the end of the axle and the hub and wear causing the hub to go farther on the axle than normal So a thorough inspection of the entire assembly is a very good thing to do and replace or repair all worn parts.
Norm

hull 433 · Post by **hull 433** » Wed Jul 27, 2022 6:12 pm

The wheels are getting new bolts, so I'll cut and peen them properly as you suggested. Thanks for the "one thread" note. One of the axle nuts was very firmly set, the other not so much. Neither had cotter pins, probably because they were removed when re-restoration started. Looking forward to getting into the axle.

Scott_Conger · Post by **Scott_Conger** » Wed Jul 27, 2022 6:38 pm

If you will show a better photo of that axle, you'll probably get advice to replace it...it looks pretty tough. If so, that in itself is enough to break the axle housings and do a through refurbishment. As is often the case, more information, often via photos, adds more to the story than just "the wheel clunks once per revolution". I'm glad you included that photo.

I looked at your car via another of your threads. It looks like a very nice car.

hull 433 · Post by **hull 433** » Wed Jul 27, 2022 6:59 pm

Thanks, Scott. I'm looking forward to getting her safe and ready for the road.

Here's a view of the rear axle after the wheels came off. I'll take a few more of both axles over the next few days.

Post by **JTT3** » Wed Jul 27, 2022 9:16 pm

Just curious you do see there is a axle key on your brake. What’s that about? Ha, probably just put there after wheel was removed, i at least hope so.

Post by **TXGOAT2** » Wed Jul 27, 2022 10:15 pm

The axle taper looks fretted and the key looks a bit worse for wear. Was the hub tight on the axle shaft? If not, it may have made the noise. It should have been somewhat difficult to get the hub off the axle shaft.

Scott_Conger · Post by **Scott_Conger** » Wed Jul 27, 2022 10:46 pm

looking again at your drum, the wheel has been running for a long time "too far in" on the axle. The parking brake shoes should not be touching the drum, and there should be NO marks on any bolt/nut heads associated with the backing plate. Such installation will most certainly involve wheel bolt/nut coming in contact with stationary features on the axle backing plate (and there is evidence of it). If ever there is or was a cause for a "thunk" when rotating the wheel, this is it (and it may be the ONLY "it").

The axle shaft, well it is it's own subject entirely and possibly worthy of its own thread after test-fitting your wheel(s) and seeing what you really have going there.

Once you get the correct bolts/nuts on your wheel you may even find that the wheel will not even rotate at all. If so, you can be pretty certain you found the "thunk"...and if adding some shims to the axle moves the wheel out to where it should be and solves it, then you definitely found the "thunk". Here's a hint: when installed and socked down, when new, the brake drum would NOT cover over the backing plate. In fact, when things fit correctly, you can sometimes even see a hint of brake shoe peering out from inside. Cars like yours...well they almost always overlap to some extent...that extra inward seating invariably starts to let rotating bits foul with non-rotating bits.

even so, you may wish to do a complete teardown to assess the internal shims (the endoscope will show if passenger side is bronze or babbit and if bronze, all but obviates the need to tear the axle down to see what you already saw with the endoscope...the likelihood of a bronze washer on the right side and babbit still on the left is pretty remote, I think). Now, I don't disagree with the wisdom of tearing it down to be absolutely sure...I just disagree that what you described "had" to be an internal problem (from a probability and design standpoint there is little internally which would cause a bind or bang once every revolution of a wheel...pretty much any as-is T that ever came through my shop exhibited that exact issue to some extent or at least had evidence that it had in the past).

Post by **Steve Jelf** » Thu Jul 28, 2022 12:05 am

Steve, I absolutely NEVER said to ignore the noise!

That's right. We were typing at the same time, though I posted a few minutes later. I'm slow.

My comment was really about the results of letting things go.

I agree with the idea of scoping out the inside to see what's there. If that's inconclusive, then I would dig in before driving any more.

From that photo of the hub bolts it looks like some new, longer ones are called for. Since we lost RV, are his high quality bolts or their equivalent still available from the parts dealers?

hull 433 · Post by **hull 433** » Sat Jul 30, 2022 11:39 am

Here's a view of the left rear axle, with no wear evident on the brake shoe mounting bolt.

Also, a view of the right rear axle, showing the amount of play. With the dust cover held firmly in place, the axle has 1/16" play. The left rear axle has no play. I haven't gone through the differential housing yet, and will this weekend. I'll look for an endoscope as well.

Scott_Conger · Post by **Scott_Conger** » Sat Jul 30, 2022 11:55 am

Either your new dust cover is not seated far enough or your wheel is going on too far. Or both. The wheel is scrubbing on the dust cover and it appears that the key went on too far up the axle shaft at one time, bending the cover and "pecking" at the cutout for the key. This catching would happen when the wheel was rotated. That could well be your "thump".

they're never (or rarely) there, but a front wheel felt seal is supposed to fit in the recess of the rear hub...the wheel should never come in contact with the seal cover...only the outer wheel-felt should. As it is, your wheel is grinding against it.
Go here for more info: http://www.mtfca.com/discus/messages/82 ... 1541507398

Scott_Conger · Post by **Scott_Conger** » Sun Aug 21, 2022 10:54 am

so...........did you resolve this?

hull 433 · Post by **hull 433** » Sun Aug 21, 2022 12:09 pm

Not yet. I'm finishing up the rest of the car's reassembly before I undo the rear. I want to keep too many parts from floating around and mull on the advice before digging in.