[junkyardjeff]

Could a bent axle cause a vibration similar to a out of round brake drum?,I thought the rear drums were out of round on my 65 galaxie but new drums did not fix the problem. It also has a vibration above 60 and I am wondering it the two are related,I have not inspected it at this time but I am trying to get some ideas on what is causing these vibrations. Jeff

[advanced design]

Does the vibration only come in above 60 mph?
I would address the most likely culprit first - tire and wheel vibration due to imbalance with the tire / wheel assembly.

Are you experiencing a brake pulsation? A pulsation feeling when applying the brakes? Do you have front disc brakes?

Additional information will help identify the potential problem.

[junkyardjeff]

I am having a shudder comming from the back when the brakes are applied,I found it by appling the emergency brakes.I dont feel anything through the pedal only the rear of the car shaking and new brake drums did not help. The vibration comming from the rear probably is always there as the floor ****er always shakes but is really noticable above 60 and I have new tires on the rear and I would think when they were balanced the installer would of mentioned the rim bent due to too much weights needed so it gets me to thinking a rear axle is bent causing the vibration and the shudder when stopping. Jeff

[advanced design]

Hi Jeff,

Here are some thoughts I have from most to least likely.

Rear brake shudder possibilities
-axle seal or wheel cylinder leak allowing oil / fluid to contaminate the brake shoes. I'd pull the rear drums to check.
-out of round brake drum
-brake drum not mounting flat on axle surface
You can check run out of the axle easily enough with a dial indicator.

The vibration over 60
-tire wheel imbalance. Has a weight come off or the tire shifted position on the wheel?
-wheel bent
-drive shaft removed and reinstalled 180 degrees off
-u-joint failing
-drive shaft imbalance
-drive shaft joint angles
-bent pinion shaft

[junkyardjeff]

The vibration was worse as the front U joint I had installed at a local driveline shop failed with less the 3000 miles so its much better now but there is something still there. I am going to put the rear on jack stands and watch the wheels turn and then remove the drums and check the axles as I do have a dial indicator somewhere,I need to inspect the shoes also as they came off a car I parted and but over 75 percent of lining on so that might be the shuddering. The drums and shoes that were originally on the car were toast and I had a set of drums and good shoes from a parts car so I put them on but it seemed the drums were out of round so I bought new ones and still the same so it could be in the shoes as I dont remember it doing it before the shoes were put on. I never drove this car above 60 before I changed the motor and trans and I do not know the history so the vibration from the rear could be a bent axle of could be from the driveshaft as it came from a parts car with unknow history too. Jeff

[advanced design]

Originally Posted by junkyardjeff

The vibration was worse as the front U joint I had installed at a local driveline shop failed with less the 3000 miles so its much better now but there is something still there.

This indicates either an improper installation, an incorrect joint angle, a bad tail shaft bushing or worn transmission mount. The front and rear drive shaft joint angles should be the same within 1/2 degree. If not a second order driveshaft vibration will occur.

[74chevyflat]

other causes for driveline vibrations above 60 mph, are : loose transmission to bellhousing bolt, loose bellhousing to block bolts. bad transmission mount. faulty u-joints, bent axles,driveshaft etc. if u let it keep on it will absolutely destroy your car if u drive above 60 alot.i had all of these symptoms and the out come was not so pleasant. A broken driveshaft exploded bellhousing, smashed and wrinkled bottom side of body. broke gas tank. and 20 bucks of gas on the highway. i`m almost rounded up all the parts to put it back together. it`s an expensive process.

[junkyardjeff]

Its a bent rim,I am going to get two new rims for the rear. I am going to replace the brake shoes to get rid of the shudder when the brakes are applied as it has to be them as I just put on two new drums. Jeff