C15 Vibration

I replied to your PM. Someone but flywheel in wrong. Flywheel thickness needs checked also. Bolts can rub discs.

 

My problem recently was the local tire shop did not ensure my brake drums were centered on the hubs as well as the wheels being centered on the drums. At 40-45 mph it felt like the whole truck was going to vibrate to pieces. I now carry the Tru Balance tool set to properly install all drums and wheels together anytime I have tire work done.

 

I’ve done my own brakes through out the years on 2 trucks and friends trucks, I’ve never ever heard of centering the drums, wheels nor had a vibration due to not centering such. I’ve switched drums and tires and still never had a vibration. Only vibration I’ve experienced was a pair of Kelly front steer tires and one was out of round. My truck today has disc brakes. I know about a lug nut that “centers” the wheel on the hub.

 

Tru Balance makes the centering tool(s) for the various types of hubs you have. You can order for newer hub pilot or older stud pilot. I now use the tool and the results are amazing. The tool centers your brake drum and your wheels.

 

I had new shoes put on my trailer and it's been bouncing intermittently since I then.

I kept the old drums.

I wonder if they didn't center the drums and/or wheels when they did the brake shoes.

Could it be a source of this bouncing problem while braking?

Thank you

 

I have had a lot of problems with trailers bouncing when the brakes were applied. Trailers have been rotated through here fairly frequently.
Some had hub piloted wheels on Budd assemblies. The holes for the studs were to large and the pilot hole was to large for the hub. Learned that we could look at the drum center hole inside the two rims and see the drum off center on the hub. If it was loaded, needed to go and we had no drums we did this a couple times. Just tighten the inner nuts snug. Then pry the drum around until the space between the drum center hole and the hub is as equal as possible. Then tighten the wheel lugs. That worked OK until we got the correct drums.
Others had Q Plus shoes on Q cams or vice versa.
I have seen new drums that are out of balance. Maybe they are out of round?
Just some thoughts on things to look for.

 

It is very easy to check if your wheels and drums are “tru balanced”.

Wheels: remove 3 lug nuts at 10, 2 and 6 oclock and the wheel lugnit “eyelets” should be dead center on each stud.

Drums: remove the wheels and the drum eyelets should be dead center on the studs. Often you have to clean the tabs on your hub to get rust, dirt or mag chloride off the tabs.

If drums and wheels are not centered on truck or trailer you will hop, shimy and shake thinking the tires are out of balance.

 

YES. A buddy did his brakes and when spinning the drums there was a bad rubbing in one spot as he spun the drums around by hand. I told him to check and see if the drum was “dead center” on the studs…they were not. I told him to remove the drum, clean the hub tabs that the drum guides and rests on and problem solved.