Unbalanced brake drum

[51shoeboxer]

My 1951 Ford convertible has a front brake drum that is 8 oz. out of balance. My Shoebox guru says to forget about it because the imbalance radius is so small, but I am concerned about it. What do you think?

 

[Kube]

Eight ounces? Eight?

That's a LOT. Are you sure it is eight ounces?
Eight grams perhaps?

 

[J Franklin]

If it is too unbalanced it will show up in the ride and tires.

 

[51shoeboxer]

I used a magnet, bolts, and a postal scale to determine the imbalance; it was 8 oz.

 

[alchemy]

I used JB Weld to attach a 1/4” chunk of steel to the outer surface of a 40 front drum on my car a few seasons ago. Hasn’t fallen off yet.

 

[51shoeboxer]

That's the sort of answer I was hoping for.

 

[cas3]

I would grind off whats needed if you have a way to static balance them, like on the spindle with dry bearings set loose.

 

[rich b]

Take it to shop where they balance engines; should be able to fix it right up.

 

[Kube]

Take it to shop where they balance engines; should be able to fix it right up.

Bingo!
I'm still trying to comprehend an eight ounce out of balance condition. That's huge!

 

[TerryOH]

Any engine rebuilder should be able to guide you to a balance shop.

 

[flatford8]

Bingo!
I'm still trying to comprehend an eight ounce out of balance condition. That's huge!

I can’t believe something isn’t visible…..8 oz doesn’t sound like a lot…until you call it “half a pound”!….on that small of a diameter …..any tires I’ve balanced take 2-4 oz…..but the diameter is so much more….can you show us the method for checking it that you’re using?………Mark

 

[Kurt in NJ]

How much oversized is the drum? might be better to buy new instead of paying to have it balanced

 

[tubman]

How much oversized is the drum? might be better to buy new instead of paying to have it balanced

This makes a lot of sense. Why put any money into an obviously problematic brake drum? $90 at Rock Auto.

 

[rich b]

Bingo!
I'm still trying to comprehend an eight ounce out of balance condition. That's huge!

I can’t believe something isn’t visible…..8 oz doesn’t sound like a lot…until you call it “half a pound”!….on that small of a diameter …..any tires I’ve balanced take 2-4 oz…..but the diameter is so much more….can you show us the method for checking it that you’re using?………Mark

He didn't mention it; but I looked up new '51 front drums and they seem to be obsolete in the regular replacement parts market.

I found repop drums listed that look to be Argentina full cast iron.

I have seen one of those; but for an F-1, that machined "off center" which leaves one side of the drum thicker than the other. Could very well be way heavy on one side.

 

[flatford8]

Comment Deleted

 

[Krylon32]

Before I became a Boling Bros dealer I was using Lincoln drums that were foreign made from another manufacturer and out of balance drums were common. Fortunately I only sold maybe a dozen pairs of them on customer chassis before going to the Boling USA made drums. No further problems. I did my best to help the customers with the bad drums. Most of them had them spin balanced with the tire and wheel on the car.

 

[Tim Ayers]

Bingo!
I'm still trying to comprehend an eight ounce out of balance condition. That's huge!

I agree. 8 Oz spinning around out of balance must be causing one heck of a vibration.