jasonr

So I just noticed that my 1989 LX 5.0 started having these vibrations while not accelerating. It only happens after around 55mph and when I let go of the accelerator. I have ruled out a drive shaft and U-Joint problem as I observe the vibrations in neutral as well. Also I just got the U-Joint changed around 15k miles ago.

Now my question is this:
Could it be the transmission or is it merely an alignment issue?
Also could it be an engine mount issue?

Any thoughts would be appreciated.
Thanks

Tony71502

Where do you feel the vibrations? If you observe vibrations in neutral then it can't be an engine mount as the engine is barely working.

The driveshaft is spinning fast at that speed, so yeah it can still be that or the u joint. An alignment issue can definitely be a cause.

jasonr

I feel the vibrations everywhere, not just the steering wheel.
Does that help narrow down whether its a u-joint issue or an alignment one?

Regarding alignment: shouldn't the car start drifting to one side when i let go of the steering wheel? It stays pretty centered.

Tony71502

I don't think you would feel it in the steering wheel if it was driveshaft related. My best guess is something along the lines of bad ball joint or alignment issues... but without driving it or inspecting it, it's just a guess.

You can have front issues without drifting to one side of the road.

Check your tire tread, do you have cc plates with those big rims. Bad alignment from no plates could eventually cause problems.

Tony71502

You should probably let Marky Mark drive it... give the car some good vibrations.

gunpig0313

You could also check the balance of the tires. It's common around 55 mph for the to vibrate if they out of balance.

HACKGT350

i was gunna say go get your wheels rebalanced. its only like 15 a tire at most places.

jasonr

The tread looks fine, but then again, the vibrations JUST started. And yes, i do have camber/caster plates. I will take it to get the tires balanced.

Any chance its the tie rods or something like that?

gunpig0313

Doubt it Bro.

HACKGT350

very doubtful its the tie rods. a weight probably fell off while you were driving. you can ask them to check the front end out anyway, they will check for free.