Driveline vibes.

[Edster]

My vibes start at 45mph and above although I have reduced them by adding a hose clamps and moving them along the shaft. I am not finished yet, but I was wondering if there are anymore "old school" tricks. I've replaced both U joints, and the car has the pumpkin that came in it but the hogs head is different. I was wondering if pinion angle might have something to do w/ it. I had a Falcon that had a similar problem and all I did was shim up the diff, under the front side of the spring pad to fix it. The 'Stangr has been in my family since 1983 and I don't ever remember it having the vibes.

 

[Rapid]

Does it occur only in third or in any gear at 45?

Does it occur at a specific RPM no matter the speed?

 

[D.Hearne]

I'm going thru the same problems with my 77 Comet. Other things to look at are the pinion shaft and bearings, pinion yoke (length and runout) Transmission tailshaft bushing wear, driveshaft length, transmission slip yoke wear and length. Also look at runout in the driveshaft. I've changed everything and still have a vibe in mine. It's either coming from the engine or the pinion shaft is bent.

 

[Edster]

Rapid: Good point I will check it out in a different gear.

D.Hearne: Is your Comet a six? I had a Maverick that had a vibe but I was told that the Ford sixes of that era had an inherent vibe to them. The quality control in that era was at its worst.
I had the same vibes w/ two different hogs heads. The one in there now was rebuilt in the mid 80s but hasn't been run since 93. The driveshaft is the one that came w/ the car. The same for the slip yoke an it doesn't seem to have any noticeable wear that would cause vibes. If its tranny bushing wear I'm not going to worry about it as I will be removing the C4 and re-installing the 4 speed. But I will check out the busing in the 4 speed. It doesn't seem to be too hard of a job to replace the bushing. Getting it out is another matter. I wonder if any of the auto parts stores rent such a tool.

 

[D.Hearne]

The Comet has a 331 topped with a repop 3x2 carb setup. The tailhousing bushing is easily removed with a hammer and a thin flat bladed screw driver. It's not a solid round piece, but has a cut all the way thru the length of it. Just take care not to damage the housing in bending the bushing toward the center of the hole thru the housing.

 

[82CapriRS]

Had the driveshaft vibration with the 82 capri I had as well. While I don't recommend this for safty reasons, here is what I did. As long as nothing else is mechanically wrong as previously mentioned. Put the rear on jack stands. Block both front wheels. Have someone sit in the car and bring it up to speed where the vibration happens. Use a tire marking crayon, and, get as clost to the drive shaft as you can in the front and rear of the drive shaft to make a mark. Don't get too close or the mark will go all the way around the shaft. Put the worm drive portion of the clam 180 degrees from the center of the mark.

 

[TurboDoctor]

I would suggest just pulling the shaft out and taking it somewhere and having it checked. I had a shaft balanced at a local jeep shop and it cost me like 20 bucks. A lot easier than trying to chase out the vibration with hose clamps. If the shaft is ok you know you got problems elsewhere. I don’t think your problem is in the pinion angle. Vibrations on shafts are usually the result of a horizontal misalignment. If you rear diff was pitched up or down your u joints should be able to still have the orbital variation to handle the change in degree unless it was severe. Good luck