Thumping noise in my 62

[Jerry K.]

Re: Thumping noise in my 62

Buy some radial tires to drive on. My bet it is tires.Had "New" 6.70X15 Cokers that 3 year old mold dates that split at the bead when put on the rim. I had them in my basement for two years, still wrapped while finishing the car.

[Paul J.]

Re: Thumping noise in my 62

Gerald and Terry, he said that it goes away when he applies the brakes. Everything he said points to a tire, but any excentricites in rotation caused by flat spots, loss of a weight, split cord, etc. would still be there under braking. It is less likely a tire than something in the suspension being loose.

Paul

[Paul J.]

Re: Thumping noise in my 62

Terry and Gerald, he said that it stops when he applies the brakes. I would agree that it could be a tire except for this. The rotation excentricities of an unbalanced tire, or one with flat spots or a busted cord will not go away under braking.

Paul

[Philip P.]

Re: Thumping noise in my 62

This is for my information, but are roller bearings adjusted the same and the taper bearings? Also the adjustment for the brakes is uniform drag and then back the adjustment 12 notches, that will eliminate any drag. IT IS EASIER TO SEE IN BOLD..............
Phil

[Mike P.]

Re: Thumping noise in my 62

It was minor and that's where the Dychem came in. It was obvious after applying it to the edge of the drum.

I am still trying to isolate the thumping noise. I coated the brake drums edges with a white marker and switched drum locations. I drove at the 30-40mph range and still had the same noise. I then pulled all wheels and looked for any tell-tale marking from the drum contacting the backer plate. There was no contact marking. The brake shoes look good, however, the compress springs (not the brake cylinder return spring) on each shoe seem to vary slightly in pull out resistance. How much pull is normal to compress the spring?

[Thomas H.]

Re: Thumping noise in my 62

I had a similar issue on my 60. I could rotate the front tire by hand and hear a rotational drag in one spot. Long story short, I believe in the ST12 there is mention of loosening the bolt on the back side of the backing plate that attaches the piece that holds the springs at the top. Once it is a bit loose you hit it with a hammer and it shifts to help center the shoes in the drums. Sure enough, I did just that and now the wheels rotate evenly and I could adjust the brakes per the procedure.

Could be worth a shot.


Tom

[Dennis C.]

Re: Thumping noise in my 62

The brake shoes look good, however, the compress springs (not the brake cylinder return spring) on each shoe seem to vary slightly in pull out resistance. How much pull is normal to compress the spring?

The 1961 passenger car shop manual only indicates spring rate for the primary spring (grey in color and spring rate of 40 lbs) and secondary spring (black in color and spring rate of 50 lbs).

You need to start eliminating potential problem areas. Try jacking the car's rear wheels (there is a safety concern here, please take all precautions) and have someone work the accelerator while you listen for noise at the rear wheels and the balance of the driveline.

Dennis