[AdamCali65]

Hey all,

At around 50 mph the car starts vibrating. Its not extremely violent but its very noticeable, I drive faster it goes away, I drive slower it goes away.

The car has had an alignment, balancing, 4 tire replacement, new lower control arms, new sway bar, replacement of bushings in the front suspension (upper control arms, strut rod bushings, etc), new shocks, new springs, new saddle perches, and a new idler arm.

Could it be the drive shaft out of balance?

Thanks,
Adam

 

[Guest]

when did this start?

did it happen after you changed some parts?

if so what parts?


sit in the car with it in park, e brake on and foot on brake.

hold the throttle 1/4 open for 15 seconds then at 1/3rd open for 15 then 1/2 for 15. does it vibrate?

is the vibration constant or does it oscilate?

does it get worse the faster you go?

you can put the engine in neutral while your driving if you are careful, remove foot from gas and see if the vibration changes.

 

[highflight]

Items I learned to replace to fix this problem...

Have you replaced your 48 year old cracked harmonic balancer?

Don't use the urethane mounts ...they are too hard and transmit vibrations throughout the chassis.

And finally the cure, I discovered the rear axles were bent slightly and replaced with new stronger axles. If you jack up the rear of the car with the wheels off and run the car, you can easily see if bent.

 

[AdamCali65]

67cpe,

It doesn't vibrate when I do that, I dont think its the engine. I feel the vibrations more in the steering wheel than anywhere else but the suspension seems to be in check.

 

[AdamCali65]

highflight,

The harmonic balancer is in great shape, I inspected it a few months ago when changing the timing chain. And like I just replied to 67cpe, I feel the vibrations mostly in the steering wheel, and there is a good amount of vibration in the shifter at higher speeds than 50 (75, etc) and same with the passenger seat, but these might just be normal.

Thanks.