On my 74 I get a vibration when doing anything over 65 mph. I have new tires all around, new radius arm bushings, and a new center link or drag link (the one that goes from the pitman arm to the right side). Any ideas, everything underneath appears solid I can not find any loose parts, the tires a less then a month old. Any ideas please. TIA

William (Tony) Whited
74 F350 Ranger XLT Super Camper Special 460
77 F150 Custom 460
77 F250 Custom 460 (parts truck)
El Paso TX
Semper Fi

 

Tony, I suspect U joints.

John
jowilker
[link:www.ford-trucks.net/users/jowilker|Club FTE since 01 01] My FTE Page

[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NC Truck Owners] NC Ford Truck owners group

66F100s Rule
In the cool still quite of night you can hear chevies rusting away.

 

Did the problem start after the new tires?

1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

The u-joints appear to be solid. And no I had the vib before the tires.

William (Tony) Whited
74 F350 Ranger XLT Super Camper Special 460
77 F150 Custom 460
77 F250 Custom 460 (parts truck)
El Paso TX
Semper Fi

 

Had a vibration 40 to 50, to make a long story short I ended up with new U joints, center support and drive shaft balance. All is well now. I tried replacing one thing at a time starting with center suppport, vibration worse then new U joints, vibration got worse, so ended up at the balance shop and wouldnt you know they would not balance the shaft unless they installed the center bearing and U joints them self, so ended up spending double in the long run. Live and learn, worth it in the end. I have a 2 piece drive shaft.

Bob L 74/F250/390

 

try rotating your driveshaft 180 degree's first, it's a lot simpler and may fix the problem, just unbolt it put the tranny in neutral and turn it 180 and bolt it back on

 

I put in new bearings and I rotated the drive shaft 180 and it still didn't fix it. Any other ideas? It seems to be more of a shudder vice a vib. TIA

William (Tony) Whited
74 F350 Ranger XLT Super Camper Special 460
77 F150 Custom 460
77 F250 Custom 460 (parts truck)
El Paso TX
Semper Fi

 

the idea with rotating it 180 is to keep everything else the same and rotating it 180. I'd see if you can notice if any of the tires are missing their balance weights, like if they slipped off on the way home or something. Also price and see how much a new driveshaft(s) cost.

 

Well here is where the problem stands, on the advice of the list adn some message board traffic I replaced the front wheel bearings both sides, and rotated my driveshaft 180 degrees. I still have the vibration (or more like an interminite shutter above 65) that I feel in the steering wheel. I know I have worn out shocks could that be the problem? Or do I need to try and have the driveshaft balanced? Could the carrier bearing be going out? All the tires are new I have all the weights on them and the shutter was prior to the new tires. TIA


William (Tony) Whited
74 F350 Ranger XLT Super Camper Special 460
77 F150 Custom 460
77 F250 Custom 460 (parts truck)
El Paso TX
Semper Fi

 

Tony, If you fill comfortable doing this, or if you don't please don't. Put the truck on a rack or wheel stands and start it and run it in gear ideling. Get some kind of stable source with chalk on the end and very slowly move to the center of the ds until it barly touches. If the chalk mark goes all the way around it is true, if it bumps it needs to be trued up aka balanced.

We got into a ARE YOU CRAZY match once before over this issue, and I am not recomending that you do it, just offering one way to do it.

John
jowilker
[link:www.ford-trucks.net/users/jowilker|Club FTE since 01 01] My FTE Page

[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NC Truck Owners] NC Ford Truck owners group

66F100s Rule
In the cool still quite of night you can hear chevies rusting away.

 

you havent said weather you have takin the driveshaft out to check those joints and center support. the only way to check those u joints is to take the shaft out rock the joints back and forth real slow any type of binding or grinding or stiffness and the joint is bad same with the center support.

 

 

This is like De Ja Vu all over again. I too have the same type of vibration or so it sounds.

I have replaced both U-joints, the front and back yoke, transmission mount and had the driveshaft balanced. Still, I have the vibration, at about 65 MPH.

I suspect since it is a high frequency vibration that it is a drivetrain vib. My next plan of attack is to change the transmission. I believe the tail shaft bushing is bad. That would make it vibrate like a mad dog. Changing it is a problem in that it would require special tools to remove and reinstall. A transmission on the other hand is $125.00 and I could change it out in about 3 hours.

I will, if you like post my results. I had installed a different rear end a couple of months ago (3.50's) and I know it could be carrier bearings but since the vibration is a high pitched vib I still think it is drive train related. The vibration doesn't go away after pushing in the clutch and I do have a 3 spd. The prior stock rear end (3.00) didn't spin up the drive shaft as high as this one and I didn't drive the truck much faster than 70 Mph.

Good Luck

Fred

 

Well thanks to all that responded to my questions. It turned out that the vibrations was caused by bad shocks. New shocks no vib. Thanks again to all.

I also did the jackstands and idle thing, everything appeared got to go.

William (Tony) Whited
74 F350 Ranger XLT Super Camper Special 460
77 F150 Custom 460
77 F250 Custom 460 (parts truck)
El Paso TX
Semper Fi

 

Replacing the shocks is only a mask to the problem. As shocks can't cause a vibration. If you have tried all the other things pointed out on this thread, I would suggest that the brake drums are out of ballance! For some unknown reason, even the FoMoCo drums can have bad ballance problems from new. I went throught 8 drums of various manufaturers to finally get two that were well ballanced. What an amazing difference they make! The truck is now dead smooth at any speed (even 90+) If you find a shop that will chuck them up on a ballence machine, I'm sure you'll be amazed at how bad the ballance is! I never found anyone who could ballence them, so I had to keep having them checked till I found good ones! I don't know if this is your problem, but It was a dramatic difference for me. Give it a shot.