Un Known Vibration

GaBear · November 22, 2008

I have a bad vibration when going down the road its at its worst between 40 and 60 MPH. I've already replaced all the Universals on the drive line and the Suport Bearing. That helped a little but I've still got the Vibration. Any guesses as to what it can be. My thinking is it maybe the rear bearing on the tranny or the tranny its self.

Info On Truck

95 GMC 1500 Ext Cab

5.7 Litre

Auto Transmission

All Factory-No Mods to truck other than some Dress-Up

228,000 Miles

2000DV4.8 · November 22, 2008

I'd check tires and wheels first.

Zembonez · November 22, 2008

I assume you have gone over the tires and wheels thoroughly?

Possibly a driveshaft out of balance?

If it is speed (rather than RPM) generated, it's something behind the transmission or in a tire/wheel. (yeah I know... Captain Obvious) A bent or out of round wheel, bad tire, unbalanced or damaged driveshaft... maybe? It could even be a bent axle. Even worn out shocks can let a vibration that would not ever be noticed turn into a monster.

These are just a few places to look if you haven't already. Really hard to know for sure from here.

GaBear · November 22, 2008

I assume you have gone over the tires and wheels thoroughly?

Possibly a driveshaft out of balance?

If it is speed (rather than RPM) generated, it's something behind the transmission or in a tire/wheel. (yeah I know... Captain Obvious) A bent or out of round wheel, bad tire, unbalanced or damaged driveshaft... maybe? It could even be a bent axle. Even worn out shocks can let a vibration that would not ever be noticed turn into a monster.

These are just a few places to look if you haven't already. Really hard to know for sure from here.

Yeah I've already checked the tires and wheels. The Shocks could be a culprit. As I said the Truck is Original. They will be 15 years old in January. I'll jack the Truck and see if I see any problem with them. I've been thinking about taking it to a local drive line place but don't want to spend the money needlessly. This Guy charges $75 just to but it on the Rack.

Zembonez · November 22, 2008

I assume you have gone over the tires and wheels thoroughly?

Possibly a driveshaft out of balance?

If it is speed (rather than RPM) generated, it's something behind the transmission or in a tire/wheel. (yeah I know... Captain Obvious) A bent or out of round wheel, bad tire, unbalanced or damaged driveshaft... maybe? It could even be a bent axle. Even worn out shocks can let a vibration that would not ever be noticed turn into a monster.

These are just a few places to look if you haven't already. Really hard to know for sure from here.

Yeah I've already checked the tires and wheels. The Shocks could be a culprit. As I said the Truck is Original. They will be 15 years old in January. I'll jack the Truck and see if I see any problem with them. I've been thinking about taking it to a local drive line place but don't want to spend the money needlessly. This Guy charges $75 just to but it on the Rack.

If those shocks are original, they were worn out 200,000 miles ago. I doubt they are doing anything other than taking up space now.

GaBear · November 23, 2008

I assume you have gone over the tires and wheels thoroughly?

Possibly a driveshaft out of balance?

If it is speed (rather than RPM) generated, it's something behind the transmission or in a tire/wheel. (yeah I know... Captain Obvious) A bent or out of round wheel, bad tire, unbalanced or damaged driveshaft... maybe? It could even be a bent axle. Even worn out shocks can let a vibration that would not ever be noticed turn into a monster.

These are just a few places to look if you haven't already. Really hard to know for sure from here.

Yeah I've already checked the tires and wheels. The Shocks could be a culprit. As I said the Truck is Original. They will be 15 years old in January. I'll jack the Truck and see if I see any problem with them. I've been thinking about taking it to a local drive line place but don't want to spend the money needlessly. This Guy charges $75 just to but it on the Rack.

If those shocks are original, they were worn out 200,000 miles ago. I doubt they are doing anything other than taking up space now.

Well looks Like my project Car will be on hold while I work on the Truck........By the way after a quik inspection the Shocks are not leaking and are still pretty stiff for thier age But I agree I do need newer ones.

pennzoil29 · November 23, 2008

Carrier bearing or do the newer trucks even have them?

GaBear · November 23, 2008

Carrier bearing or do the newer trucks even have them?

If You mean The Yoke Bearing......yep Been Changed

Mike G · November 24, 2008

Is your truck a 2 or 4WD. Does the vibration occur in the seat or in the steering wheel? Any signs of unusual tire wear? I am leaning back on the driveshaft out-of-balance, but want to be sure all info is exposed...

--Mike

GaBear · November 24, 2008

Is your truck a 2 or 4WD. Does the vibration occur in the seat or in the steering wheel? Any signs of unusual tire wear? I am leaning back on the driveshaft out-of-balance, but want to be sure all info is exposed...
--Mike

Oops guess I forgot to include that. Its a 2 wheel drive. The Vibration can be felt everywhere. Guess Its Off to the Drive line experts next week.

Zembonez · November 24, 2008

Is your truck a 2 or 4WD. Does the vibration occur in the seat or in the steering wheel? Any signs of unusual tire wear? I am leaning back on the driveshaft out-of-balance, but want to be sure all info is exposed...
--Mike

Oops guess I forgot to include that. Its a 2 wheel drive. The Vibration can be felt everywhere. Guess Its Off to the Drive line experts next week.

I'm still betting on the shocks. 200K plus shocks aren't "shocking" anything any more.

Scorps · November 24, 2008

Rearend on its way out?...my car did the same thing before it went boom.

GaBear · November 25, 2008

Rearend on its way out?...my car did the same thing before it went boom.

Had a Guy look at the Rearend while they were redoing the Universals. He said the rear Looked like it was brand new. I try to change the rearend dope every 50,000 along with the tranny.

Scorps · November 25, 2008

Oh then it has to be the wheels/tires

GaBear · November 25, 2008

Oh then it has to be the wheels/tires

Nope Dun Been checked.....I'm laying my bets on the drive line being out of balance or the tranny bearing. I found a crate Tranny for $1400. Just don't have that kind of money right now.