keithb7

Powertrain..Imminent Bearing Failure?

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1953 Chrysler Windsor Deluxe C-60. I have been hearing a howl starting to develop, in what I think is the rear end maybe. It seems to be happening under certain conditions. I notice the sound climbing up the big hill back home. Only when navigating a turn in the road on the way up only. Going down the hill,  or driving around town, where it's flat I don't hear it. Last night coming up the hill I experimented a little. I could hear it on the turns on the way up. I put the tranny in neutral at the top, where it's flat again and coasted for a bit. No noise. Made the last turn in before my driveway, coasting in neutral and the sound was there for sure.  I suspect maybe an inner axle bearing?

 

I am not 100% sure on the workings of the diff. When I turn the car, the internal side andpinion gears walk around inside the diff case. Correct? This only happens while turning, when one wheel is turning faster than the other.  There are no bearings to support these side and pinion gears. Just pinion shafts and everything is submerged in the diff oil. 

 

A couple of things I am thinking. When I climb the hill home, the car is working it's hardest using every ounce of torque to maintain 30 orso mph. Is the diff under a fair amount of stress at this time? A failing bearing getting hot under this condition? The oil is topped up, I check it as part of my routine.  Maybe I am mis-diagnosing. If it were an inner or outer axle bearing, would it not make the howling noise at any time the axle it spinning? Straight while cruising around town too?

 

Next steps, I will drain the diff oil and see if anything comes out. I'll look for shiny small pieces of bearing material suspended in the oil. Is there a way to jack up the axle and turn the wheels to troubleshoot?  Any tips? While jacked up, is it possible to hold one rear wheel still while turning the other to get the diff gears turning? Maybe right after I climb the hill? I'dhate to dive in and start ripping stuff apart before diagnosing things properly. A failed bearing could be catastrophic to the diff if a bearing roller went through some gear sets. Likely taking off some gear teeth with it I suspect.

 

Maybe I will proceed to pull the carrier and get a good look. At the same time slide the axles out and change outer bearings and seals. I have never done this work before, but I think I can handle a good portion of it. Comments, tips appreciated, especially on the troubleshooting. Thanks.  - Keith

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Before you go tearing things apart have an experienced mechanic listen to it. Such noises are tricky to diagnose from a distance. Even though you have done a good job of describing it, and the conditions under which it appears.

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A little anecdote. Our motor home was due an oil change for the differential. The mechanic rang me to say the oil had a silver sheen = metal in it. No pieces, just a silver sheen.

 

On strip-down, there was one bearing with slightly too much end float that had rubbed and gouged a little of the end float control away. The bearing was failing. It would probably have lasted a good few miles before making any noise or giving any noticeable signs. I can't remember which bearing it was but I was glad I said "fix it please".

 

So I say, don't delay, drain the oil. If it has a silver sheen, it is time to find the source,  a sort of very careful forensic analysis of everything until you find it (hopefully only one problem). If a bearing is failing, it could cost you an axle as well as other parts. My last one was a little vertical movement in a wheel bearing in my 1930 Dodge Brothers 8. It turned out the bearing had been turning on the axle and the axle was worn and thus not usable.

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Thanks for your comments folks. Oil drained clean. No visible silver sheen. The life of the outer axle bearings is unknown to me. For piece of mind I will change them as well as the inner and outer seals. I pulled one side and cleaned it up. It's not rolling too smooth. It was shy on grease too. New parts ordered for outer axles. 

 

431756AC-8585-4FEE-8970-C1EFB2844C2C.jpe

 

 

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3 hours ago, Rusty_OToole said:

Did you notice the grease fittings at the ends of the axle housing?

 

Yes I knew they were there. I bought the car a year ago and did put grease in those fittings this spring. I was guessing how much to put in as I did not know if the previous owner greased the bearings or not. The only grease I found in there was about 1 tablespoon that I added this spring. I will pack the new bearings and ensure the grease cavity is has adequate reserves.

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"When two incompatible greases are mixed, one of two things generally happens: the mixture hardens and will not release any of the oil or the mixture softens and releases all of the oil. In either case, the end result is basically the same; there is effectively no lubrication.:"

It's best not to just add more grease to a precision bearing.

Wash it out and add the proper amount of grease...should be good for a long time on the rear axle bearings as long as the seals are good and proper amount and type of grease is applied.

 

]Suspension components can be greased with most any grease as long as done at proper mileage.

JMHO🙂

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C49er most likely this is the case here. Great comment. Only the proper type and amount of grease will be used while I own it, now that I am starting with new bearings and seals.

Edited by keithb7 (see edit history)

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