The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Rotational noise?

I have 1960 C-10 , LWB fleetside, with the two piece drive shaft, original four speed trans and rear end. New motor and clutch. I have a noise my mechanic called "rotational". He thinks it might be coming from the support bearing for the drive shaft. Very noticeable at low speeds. Increases with speed. I test drove it the other day thinking that if the noise was coming from the support bearing that it would be hot. It wasn't. Anyone with any experience on this? He suggested just replacing the original drive shaft set-up with a single piece drive shaft.

Crawl under and shake the center of the shafts. You shouldn’t have any play at any of the bearings.

That driveshaft center bearing is a common wear part. It was used on all long wheelbase trucks and many cars of that era. The parts are available from both auto parts stores and specialty aftermarket suppliers. It would be more economical to replace it than make up a new drive shaft. Any good shop should know how to replace it. Probably a good time to replace all the U joints as well.
Fred

If the truck was able to use a single piece driveshaft, why would GM have gone to the trouble and expense to engineer a 2-piece? It sounds like you need to RUN, not walk away from that "mechanic" and find somebody who actually qualifies for the title!
Jerry

Unbolt the carrier brg. from the frame & spin it. If it is bad you will hear & feel a grinding noise. If it is bad, replace it. If you cant do the work yourself you might be able to remove the shafts & take it to a drive shaft shop or qualified mechanic.
George

I'd suggest putting the rear axle housing up on a set of sturdy jack stands, put the transmission in high gear with the engine idling, and let the wheels spin. Then roll under it with a stethoscope or a piece of broom stick, and listen for noises at the transmission output yoke, the carrier bearing, and the rear end pinion area.
Jerry

To add to Jerry's suggestion. For safety's sake, please firmly block the front wheels, and maybe even chain the truck to a stationary object so it can't move forward. Tire tread marks across your body isn't a good thing.

Yes I think I'll pass on that suggestion. Thanks for the responses.

I’ve done what Jerry suggested before. It’s the best way to find out where the issue is.
Just make sure you have some safety issues covered. I would get a trusted friend or family member to be in the cab just in case. But not the wife!
Good cribbing under the axle and a back up on the frame. Give it a test run and then give the truck a good shaking side ways and front to back.
Don’t get too close to the tires or the spinning drive shaft, and you’ll be fine.
Better yet, find a mechanic with a lift and do it on that.

Rotational problem? Give me a break! Hope your mechanic didn’t charge you for that advice.
Don

I usually put the test vehicle tight against a wall of the shop, or park it where the front bumper is touching a heavy vehicle with the transmission in gear and the brakes set. A little common sense goes a long way, but I think that commodity has been in very short supply for a couple of generations, at a minimum!
Jerry

Let's not trash the last couple of generations of people.

My guess is that your statement was made during every generation in history.

LOL!! Probably. I know my parents weren't too fond of my friends, and I was not overly impressed with a lot of my daughters friends.

She had to explain how to Duct Tape a leaky radiator hose to the guy she was dating at the time so they could drive his car home when it over heated. She even knew enough to stop him when he tried to open the radiator without a rag over the cap while hot. He was a mechanical disaster.

I think it's important to understand not everyone has mechanical or skills. Just like not everyone has good writing skills. What is obvious to one person is not always obvious to another. It takes all kinds to make the world go around.

Good Point.
I know I take it for granted that everyone should know how to work on vehicles. That is not fair to about 80% of the population.

Good point and reminder old green. Thanks for feedback.