Engine/Transmission (1994 - 1998) Truck shakes

[PMarchetti]

I have a 96 12 valve with a 5 speed. It shakes pretty bad around 60 mph, and just a little at other lower speeds, like the tires are off balance. I've re-balanced all the tires, checked u-joints, driveline, wheel bearings, and cant seem to find whats making it shake. the stick shakes side to side, so it must be in the drivetrain somewhere. any ideas?

 

[JDKammin]

Do you have a different set of tires and wheels you can try? I had a vibration in my 96 with 5 speed and ended up being the CV joint in the front driveshaft. I had a powertrain shop rebuild the front driveshaft and fixed the problem for under $200.

 

[BigPapa]

I had a vibration I couldn't find, also. It ended up being the clutch. The sprung hub had broken and a couple of the springs had come out and they threw off the balance. Didn't discover the problem until the clutch wouldn't disengage due to the springs wedging in the pressure plate. It's a pretty common problem with the 12" clutch.



Hope it's something else, but thought I would give you my experience.



Scott

 

[PMarchetti]

I had a feeling it might be the clutch throwing a spring. it's about time for a new clutch anyways... when i can afford it. thanks for the help.

 

[Vaughn MacKenzie]

On my '98. 5 I had there was a out of balance tire vibration that was hard to track down. Ended up being two of the tires were considerably out of round. Found it out by jacking up the truck and spinning the tires.

On another vehicle I had I found out one of the wheels had the hub drilled nearly 1/4" off center. That one took awhile to figure out, was going nuts trying to solve a vibration on the highway.

 

[KHelfrich]

I dont think it is the clutch since you said it happens at 60 mph that sounds like something with the wheels or driveshafts. if it were the clutch then it would shake as rpm went up not as speed went up if you have steel wheels they can be bent if the lugs are tightened before they are full seated on the hub i had that happen to my truck once

 

[McCRam]

You beat me to it, but I was going to mention my last balance issue was a bent wheel. I have no clue how it was bent. This was on an aftermarket aluminum wheel.

 

[PMarchetti]

Well the weird part about it. I jacked up the rear end and got it going 60, and there was no shaking, not even in the stick. it has over 200, 000 on it, so i'm not shocked that it shakes, but it still bugs me.

 

[DieselDoghouse]

OK The village idiot will now speak.

I think we can forget your front CV joint IF you still have a shake in 2WD - how can a stationary shaft induce shake??

No shake while jacked up and turning the equivalent of 60?? HMM - your wheels are turning but the treads aren't down… If balance were a major issue the inertia imbalance should still give a shake. BUT if one or more tires are eccentric - I can understand the basketball imitation starts when the treads hit the ground. My vote is for an out-of-round tire. If the rear shocks are old they can't mask the hop.

 

[PMarchetti]

hmmm, well, you'd think after having all 4 tires re-balanced, you'd think the tire experts would catch that, but i'll have to take a better look

 

[DieselDoghouse]

Check with the rest of the guys/gals here but in my experience most tire balancers are designed to check for inertial mass defects - wobble, runout (along the hub axis). If the tire is subtly egg-shaped ('hump") it might go undetected. To my knowledge only the motorsport, laser-optical units at places where they shave tires are capable of this. And the big boys DO occasionally have egg-shaped tires go out - it happens.

 

[hdm48]

I had a shake that drove me nuts until the tire shop did a "ground force" check. They found 3 tires out of whack. Rotated the tires on the rims and presto, no more shake.

 

[Missouri Mule]

I had a truck tire dealer balance my tires on my Freightliner do to a violent shaking/vibration all they did was add a lot of weights to one side,ended up having a roaming truck tire man check them out. He found one front tire had a flat spot on 25 % of the trie. A new tire(s) solved the problem.



Jack the truck up put an item (tool box) in front/rear of tire and spin watch how close the tread comes to the item your using.



Your front tires could be the problem not the rear.

 

[PMarchetti]

well, sounds like a tire problem. truck goes into the tire shop tomorrow morning. hopefully that will be it. so i want to thank everyone for all the help. it is much appreciated.