What is this spring for?

[70c10]

I pulled my wheels this weekend to detail my frame and suspension and noticed all of my drums had this spring except one. What is the purpose of this spring?. Is it a noise suppressor or something?

[grayw0lf]

I am curious to see myself!?.

[chevydog66]

Is it welded on there? How is it attached? I've never seen such a thing.

[RANDY COX]

HHMm transfer heat and possibly noise.???????

[CPNEJR]

actually thats exactly what it is it keeps pressure on the drum so it doesn't rattle

chevydog66 it's not welded on

[LUV2XCLR8]

Someone Will Correct Me If I'm Wrong, I Used To Work At A Muffler
And Brake Shop For Extra Cash In The Afternoons, I Was Told By My
Buddy, The Manager, That It's Like Wheel Weights For Drums, Helps
Them Stay True Under Excesive Heat, My Old 70 Has/had Them On It.

[3 on the tree]

Old tech. That spring is to absorb harmonics (noise). Haven't seen one in years except old GM trucks.

[LUV2XCLR8]

Originally Posted by chevydog66

Is it welded on there? How is it attached? I've never seen such a thing.

NOT WELDED, JUST STRETCH EM ON, THERE IS A GROOVE THEY RIDE IN.

[70c10]

Yes they ride in a groove and are just rolled on. I figured they were to suppress noise. Can I still buy one to complete my set?. I asked the parts guy today and he had no clue. I couldn't find any info in the service manuals.

[Longhorn Man]

I think I have one burried some place...I'm making a note to look for it.

[glock35ipsc]

Back when I was wrenching, we use to have leather straps that we wrapped around drums when we were turing them to keep them from "singing". Had thin ones for rotors too. Don't know if they are still doing that or not.

[Tx Firefighter]

Originally Posted by glock35ipsc

Back when I was wrenching, we use to have leather straps that we wrapped around drums when we were turing them to keep them from "singing". Had thin ones for rotors too. Don't know if they are still doing that or not.

You bet they still do that, a rotor or drum will still sing without the strap when turning it on a lathe. Every lathe I've ever used had a selection of the straps there next to it.

[70c10]

Should I get another spring and wrap it around the drum or does it matter that I have one missing?

[Tx Firefighter]

you'll never know it's gone.

[70c10]

ok ,thanks for all the replies.

[GlennBrittain]

I deep sixed the springs on the 69 C10 SWB, I an drivining, never noticed any diferrance. Balance did not suffer without them. They must have been another nichol and dime item so GM could mark cost.

[Arctic Gearhead]

True enough!

[Longhorn Man]

None of you noticed your drums ringing at highway speed?
I noticed it on mine, they ring, like the dork at the fancy resaraunt running his finger around the rim of the wine glass.
What totally ticked me off was when I bought 2 brand new drums, no provisions for the springs.

[68LSS1]

Yes, what Longhorn Man said. They are to stop the harmonics that cause a noise not vibration.

[70c10]

Well, maybe I'll just put one on to complete the set if I can find one.

[LT4XTREME]

Last summer at a car show at the local auto tech center a friend of mine with a sweet black 66 c10 short fleet side was on the chassis dyno when a loud hissing noise started. At first they thought a air line on the dyno blew but when the truck was pulled off this grinding sound was coming from the driverside rear axle. We put the truck in another bay and pulled the wheel and drum and could not see anything wrong. So we put it back together and went to pull it out and it would not budge locked up solid. John the owner had to go out of town for a few days so he left the truck in the shop thinking the new locker and ring & pinion was messed up. Later that week when he got back to check it out again he found that the spring on the drum had expanded due to centrifugal force from running 100mph on the dyno and the spring jumped the groove into the space between the drum and the backing plate. So if you really want to know what the spring is for it's good for a weeks worth of headaches and worry.

[Super Duck]

backing plates off a later truck will bolt on and give you no problem wit hsprins, noise, and give you bigger brakes. kinda cool

[Longhorn Man]

They flew off at 100MPH?
Something was wrong with them, rusty or streatched.
I had my old GMC well over 100 MPH...the needle was pointing to the M in MPH. I held it there for a good 10 min, then I decided to back down. Held it at 100 for at least 1/2 hr.
There has been many, many times I have held it at 100 MPH. Never threw a spring.

[Longhorn Man]

It took 30 min of digging through my junk...but I found one.
$10 to your door shipped via USPS.
Interested? PM me if so.
There is another one too if anyone else is interested.

[70c10]

Andy, PM sent.