Thumping noise in my 62

[Mike P.]

My 62 has a noise while moving. The noise is a uniform thumping which is most noticeable between 30-40MPH. When I apply the brakes the noise goes away. I replaced the tires, u-joints, front wheel bearings(from ball to roller) and had the brake drums turned. The brake shoes look fine without any unusual indication of wear. I have not pulled the rear bearings since there doesn't seem to be any noise when I spin the wheels(jacked up).
Does anyone have a suggestion on what to check next?
Mike Parker, member 52615

[Gary C.]

Re: Thumping noise in my 62

Mike,

FWIW using the "bold" keys online is the equivalent of "yelling".

The NCRS webmaster John Waggoner had a similar noise problem this last summer in his '62 and couldn't isolate.

Turns out it was the rear sway bar/control link bracket broken off of the frame.

Gary
....

[Bruce B.]

Re: Thumping noise in my 62

Gary,

I understand that "all caps" is "yelling", never heard that bold was.

Bruce B

[Mike P.]

Re: Thumping noise in my 62

Gary,

Hope that I didn't hurt your hearing. I personally like bold, makes it easier to read.
Thanks for the info on the sway bar.
Mike

[Edward J.]

Re: Thumping noise in my 62

Mike since the noise occurs when you apply the brake I would be leaning toward a drum that maynot be true. A way to check this is by turning each wheel and listining for the brake shoes to be only hitting in one spot as you rotate the wheel. there should be a constant drag around the full revolution. You may need to re-adjust each brake so that the shoe just hits the drum first.

Not all machine shops take the time to clean the mounting surfaces of the drums before they mount them onto the machine. this will cause runout and will cause the shoes to move around on the backing plate and make the noise you are experiencing.

Also make sure that your hub surfaces and rear axle shaft flanges surfaces are cleaned. I would use a 220 sand paper if there rusted badly.

[Mike P.]

Re: Thumping noise in my 62

Ed,
The thumping noise goes away when I apply the brakes. The guy that turned the drums said that they were "out of round" but corrected them.
Mike

[Joe M.]

Re: Thumping noise in my 62

Check the brake springs for weakness

[Edward J.]

Re: Thumping noise in my 62

Mike sorry I miss read your post and jumped the gun. Its a rotating type noise. If you spin the front tires can you duplicate the noise? In the rear you can jack up the back of the car and install a couple of jack stands and start up car and use the engine to spin up the rear wheels and listen. make sure in rear to put some lugs on the drums and tighten so they don't fly off, just leave the tires on.

Another possiblity is when you installed the wheel bearing maybe one of them got damaged? if when you installed the race and nicked the surface with something this will make a racket when rolling doewn the street. when you spin the front wheels listen for any type of noise, they should be quite as achruch mouse.

[Mike P.]

Re: Thumping noise in my 62

I jacked up the rear with wheels off and ran up to 30-40 mph with my wife on the pedal and I held a long handle screw driver from my ear to each side of the rear end casting. The result was nothing detecting any noise ,other than engine/exhaust noise. On the front end, I pulled the roller bearings and carefully inspected them. No problem was found. This noise was present before the front bearings were changed. The bearing change was just part of rebuilding the front suspension.

[Mike P.]

Re: Thumping noise in my 62

Check the brake springs for weakness

Joe,
Should I look for approximate uniformity in tension from each spring?
Mike

[Edward J.]

Re: Thumping noise in my 62

Mike what bothers me is the fact the noise disappears on brake application, so that tells me that something is contacting while the wheel is spining, maybe one of the drums hitting or rubbing one of the backing plates? or the shoes hitting a hot spot on one of the drums.

I just grasping for straws here, I would tell you to keep open in mind and rethink if theres anything that you can relate to the nosie. Do you recall when this noise appeared? was it after a repair? I have been a auto tech for 40 years and once in a while even I get stumpped. If I had this car at my shop I am sure the problem could be solved.

just for the heck of it try what I said in my first post about spining the drums by hand and listing for a smooth drag of the br. shoe all the way around the drum. if your finding that the drums is freeing up in spots the drums are not true. good luck, Ed

[Dennis C.]

Re: Thumping noise in my 62

Mike,

Are the drums original or reproductions?

Dennis

[Mike P.]

Re: Thumping noise in my 62

Mike,

Are the drums original or reproductions?

Dennis

I have no idea. The rears look original. The fronts look newer.

[Dennis C.]

Re: Thumping noise in my 62

I have no idea. The rears look original. The fronts look newer.

The reason I ask is because of an incident I had with reproduction drums. The inner edge of the pad mating surface was too long and rubbing on one side of the backing plate. I coated the edge with Dychem to help locate the problem.

[Mike P.]

Re: Thumping noise in my 62

The reason I ask is because of an incident I had with reproduction drums. The inner edge of the pad mating surface was too long and rubbing on one side of the backing plate. I coated the edge with Dychem to help locate the problem.

Wouldn't there be some indication of wear or contact?