The Stovebolt Site Forums The Shop Area Engine Shop Need Noise and Vibration diagnosis HELP!!

I finally have our 1950 AD pickup back together and on the road. It has parts from at least 4 trucks, including a 1954? 235 motor, 1952 enclosed driveshaft and rearend. 3-speed transmission (year?). Anyway, it drives great, except when I step on the power, there is a loud noise and vibration that goes away when I let off on the gas. My friend says throwout bearing, but I'm not so sure. I'm thinking driveshaft.
Any ideas before I start tearing it apart again?
unbroke

unbroke,

The throwout bearing isn't in this equation. I'll cast my vote for the u-joint...bet your thinking the same thing!

Stuart

I would check the u-joint first. And, do it before driving it again. Could be that the ears are not properly nested into the trans half. Causes a lot of vibration, and if really bad , it can hit the housing and make a heckuva racket.

Other potential problem area, Motor mount, front or rear loose causing a shift under power. Unlikely, but a missing pilot bearing can cause vibration, but it will do it with the truck stationary revving the engine.

If it does it when the clutch is out, engaged, it can't be the throwout bearing as it is only turning when the clutch is disengaged.

Thanks, atomarc (Stuart) and KENC! Will check U-Joint! Motor mounts are new, but will check. Doesn't vibrate when stationary. It will take a few days before I can get back to where truck is. Anybody else have ideas?
unbroke

unbroke,

Does this incident mean you have to temporarily change your handle to 'broke'!


Stuart

nooooooo, tee hee. it's the truck, not me!!
I'm not broke, but I might need fixin.
unbroke

After buying my 1950, 3604 I decided to drive it the forty miles to her new home down the Tollway. After all, according to the PO he had been driving it the mile and a half to work on a regular basis for the past two years. Well the old girl, got me and my trusty dog about fifteen miles before her brakes froze up and brought the adventure to an abrupt halt. The rest of the way home she rode in style on the back of a brandy new International car hauler under contract to the Illinois Tollway.
Now the short distance that I did get to drive her told me a lot about what was in store for me. At any speed over ten mph the vibration and shaking was quite severe, she would start a speed shimmy that could only be stopped by slowing down. The wheel had to be worked through a 180° to keep it on the road and it sounded like a meat grinder inside the cab. Out On the Tollway at fifty mph, I thought my fillings were going to shake loose, even the dog was looking worried.
So when I got her home and off the hauler she went right up on jack stands and for the past eight months every thing underneath has been re-built or re-placed taken down to bare metal and repainted. All three U-joints, new motor mounts, all new steering, wheel bearings, brakes, tires, etc.
A couple of weeks ago I finally got to take her for a ride. Even though I still have the doors off for rebuilding, we took a spin round the neighborhood, open air. She felt like a brand new truck, no shakes, no vibration, no shimmy and shake, no drift, no grinding. It’s not the same ride as a new 2007 truck but she has the feel of a new 1950 truck, smooth and quiet.
Denny Graham
Sandwich, IL

OK! Thanks, again for the help! I fixed the problem! Of course it was the U-joint. Or more exactly, the fact that some idiot (ME) didn't follow the directions and didn't use any gaskets / shims between the ball collar and the transmission. RTV just wasn't enough! The universal joint yoke was banging away on the bell.
In advance, I ordered up a u-joint repair kit from Jim Carter's. That was a mistake! Unless you are a master at pressing in bushings, I recommend not attempting this! I ended up having a friend with a machine shop fixing my misadventure. Those Argentinian bushings did not want to go into my yoke. I pressed so hard I even bent the yoke.
I would have been better off just putting in some gaskets.
And no one seemed to have the gaskets in stock. I am not one to wait around for parts, so I got some gasket material from Napa and cut 4 of my own. that was the easiest part of the job! She's back on the road, thanks to the information on this site!
unbroke

glad you got er done...............

U joint