55mph vibrations??

[SuperSwede]

Recently I noticed that I get terrible vibrations in the car at 55mph and low rpm´s.. when I let go of the accelerator or goes downhill it goes away.. same thing if I accelerate or go upphill.. but on levelground with steady speed it vibrates a lot!!.. this only happends when the car is cold and runs on overdrive..

Any clues? (I´ve had the car for three months now and this showed up a couple of days ago..)

Kindly
Per

 

[BrooklynBay]

There might be a few possibilities, such as a bent driveshaft, improperly balanced tires, bad alignment, TCC shudder from having the wrong fluid in the transmission, VB might need an anti shudder spring, etc.

 

[Maniak]

If it seems to only happen under load (not under coast or de-cel) then check the u-joints. There have been more than a few people here that had a vibration under load that was fixed by replacing the u-joints on the rear drive shaft.

I'm actually had the problem twice (once from age, the other from wheeling)..

~Mark

 

[BrooklynBay]

Wouldn't the U joints also click at low speeds?

 

[Maniak]

When my first u-joint was having problems it would vibrade badly starting at about 70mph..

My 2nd u-joint caused a vibration that started at about 50..

On my flat-bed, it had a vibration at 45mph that went away at 55 and that was a bad carrier bearing (still drive shaft related)..

You also don't always hear clicking from u-joints.. and they also don't always get loose.. both my mine got tight..

~Mark

 

[SuperSwede]

BrooklynBay: could you explain this ? Sorry but english isn´t my spoken language.."TCC shudder from having the wrong fluid in the transmission, VB might need an anti shudder spring,"

The thing that makes me worried are the fact that this only occur when the car is cold and runs on overdrive.. the function of automatics are a mystery to me.. 20yrs with sticks so far..

Thank you

 

[BrooklynBay]

TCC is the torque converter clutch, but in my case I was referring to the torque converter, and VB is the valve body. TC could be either torque converter, or transfer case, which gets even more confusing. Sorry for not being more explanatory. I usually post information about this kind of stuff in the transmission forum.