VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Power glide driveline noise

1951 Styleline Deluxe 235 power glide, 40k miles. The drive line on this car has always been noisier on deceleration. kind of between a whine and a humming noise, never really thought much of it. I just replaced my totally toasted transmission mount, and now along with the noise, I have vibration you can feel. So I realize I will have to check and make sure the new mount is not touching anything and causing an issue, but is the noise on deceleration normal on these cars? On acceleration the drive line is nice and quiet, but it's getting to the point where just letting off the accelerator just a little bit will make a difference.

First bet would be the U joint. Sounds like one of the trunion bolts is coming loose.....or the U joint is bad which would not be common at 40,000 miles.
#2 would be the rear pinion bearing or the drive shaft bushings.

I replaced the u joint when I first got the car. Had 33k when I first got it. I will check to see if it is loose though

Steve,

The first fix is to not decelerate any more. Either accelerate and cruise or nothing. Problem solved.

Sorry, I couldn't help it.

I agree with Gene. It sounds to me like its the U-joint. I think everything else would seek a position that wouldn't cause a continual vibration upon deceleration.

Good luck,
Charlie

I would check the rear differential and suspension.

If I have to pull the torque tube out, is there enough room with the power glide trans to undo the u joint, let the tube drop down, pull the axles and unbolt the torque tube from the carrier and slide it forward and out? Can I get the pinion out through the back of the carrier housing after pulling the ring gear and differential out, in order to replace the pinion bearings if they are bad?

The torque can stay in the car. Remove rear cover, axle shafts and ring gear. Pull out pinion shaft-driveshaft will come with it. Not necessary to split the U joint.
The hardest part will be getting the pinion gear out of the housing as the bearings are stuck in the housing.
Note pinion lock screws on the out side of the housing must be lossened,removed.
If a pinion bearing is bad it will be the rear one which is a roller bearing. Not common. If you replace the front double row ball bearing it may go in backwards to your present one....due to changes in mid 1951.

Thanks Gene,you are a wealth of knowledge, as usual

OK, I have pulled the torque tube ball back to expose my u joint. It looks as if the cross part of the u joint is too short, as I can move the drive shaft back and forth. I definitely think this is my vibration issue. Any ideas? This has been running like this for 7k miles with no issues, until the mount change. Here is a link.
http://s1168.photobucket.com/user/Boltergiest/media/DSCN8720_zps8e5b033c.jpg.html

I don't follow your description. The front half the the U joint (front yoke) is bolted to the transmission. The rear yoke slips on the spline of the U joint. This slips back and forth on the splines as the differential and torque tube goes up and down with the springs.
What am I missing?

I think perhaps the bushing in the front of the torque tube is shot. See where the bearings are showing on the u joint? You can move the drive shaft back and forth, bearings showing on one side, move the drive shaft over, bearings showing on the other side

Time for an Oakie bushing. The bushings in the 1951 are pressed in and can be difficult to remove.

Would I be better off to pull the torque tube out get the dive shaft out of the way and drive the bushings out from the rear?

For sure.

Thanks again Gene. I will keep everyone informed as I move along

please do