'97 Silverado shakes at various speeds

bcrooms · October 8, 2018

I bought my '97 Silverado from the original owner a few weeks ago. 149k miles on it when i purchased.

It needed some attention after purchase such as:

New tires, new belt tensioner, new pitman arm, new sway bar links, new Valve Body in Trans, new A/C system O-rings,

But my issue is at 40-45 mph and 65-70 mph, the truck will shake badly until I accelerate or decelerate to a different speed.

And yes the wheels and tires are balanced correctly as far as I know. the truck itself drives great until you get to these speeds.

I notice it the most driving through local towns as the speed limits are either 35 & 45mph. I notice the higher speed issue on the 4 lanes I travel on from time to time.

Could this just be fault U joints? I do hear a noticeable "pop" when I put the truck in gear when I begin my trip to work ,etc.

Just want to track down the cause and have this truck driving as nice as it looks.

Any input and advice is appreciated,

-Brandon

bc-chris · October 9, 2018

is the front end out of alignment?? it might be worth getting it checked

also - i know you say the wheels are balanced, but it might not hurt to get a second opinion. a number of years ago my wife and i went on a little road trip to celebrate our 10th anniversary. on the way back home i got hit (we were about 2.5 hours from home). insurance wouldn't pay to transport my truck back home to get fixed becuz there was an "accredited" shop close to where the accident happened. that shop was brutal! they missed that the gas sending unit (near the top of the tank) was cracked so when i went and filled up to drive back home gas went everywhere at the gas station. they didn't reconnect the rear tail lights so unknown to me i had no rear driving lights, turn lights, reverse lights OR brake lights! they also said they had the front end aligned - not a chance! so all that to say, 'not all shops are created equally'.

so yea - if you have a shop you trust then i wouldn't worry too much about rechecking the tire balance, but if you're not sure then getting them checked somewhere else might by an idea.

**in my province (british columbia), auto insurance is a crown corporation - so everyone uses one company that's run by the province (icbc). you can get additional coverage thru private companies if you like, but all basic coverage goes thru icbc. becuz of that, they have 'accredited' shops all over the province. icbc did call me after i got my truck back and asked about my experience with their accredited shop - they got an earful!

bcrooms · October 9, 2018

I had it aligned when the new tires we mounted about 2 weeks ago.

Tire shop is trustworthy and the alignment shop is as well.

Edited October 9, 2018 by bcroomz

silveradosid · October 10, 2018

is the truck 4x4 or 2 wheel drive

bcrooms · October 10, 2018

48 minutes ago, silveradosid said:

is the truck 4x4 or 2 wheel drive

4x4 with push button.

coldsweat1906 · October 12, 2018

Definitely look into your u-joints. Had the exact same problem in my 95 Silverado, replaced all three joints just 3 weeks ago. Rides smooth as silk now.

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bcrooms · October 12, 2018

4 minutes ago, coldsweat1906 said:

Definitely look into your u-joints. Had the exact same problem in my 95 Silverado, replaced all three joints just 3 weeks ago. Rides smooth as silk now.

Sent from my SM-N950U using Tapatalk

My initial thought was the U-joints. I will check those and circle back with results. Thanks

bcrooms · October 15, 2018

Just to give an update on the issue: I have not had enough time to inspect the U-joints yet, still planning to do so.

But yesterday I had to make a trip in the truck to another town located in the foothills of the mountains near me and the 4 - lane has some steep incline in portions and the truck shook violently when I had to give it more gas for the inclined places to maintain speed limit drive. RPMs were between 2000-2300 at the time of the shaking.

The only way for me to duplicate the issue is to get the truck on an incline. Flat roads don't appear to be much of an issue.

Logan Lanfear · October 16, 2018

That probably has to do with the amount of load being placed on the truck at certain speeds. If its not U-joints then it could be a lot of different things.

bcrooms · October 16, 2018

6 minutes ago, Logan Lanfear said:

That probably has to do with the amount of load being placed on the truck at certain speeds. If its not U-joints then it could be a lot of different things.

A mechanic friend of mine is thinking the torque converter is bad

bcrooms · February 13, 2019

Update:

After investigating multiple issues, it was determined that the fuel injectors were bad, distributor cap and rotor were also bad, and had a minor coolant leak.

Fuel filter was also replaced.

Those have been fixed/replaced.

My trucks seems to be much better now

bcrooms · July 2, 2019

Update: shake has returned but at a higher speed and RPM than before all the parts mentioned were replaced. Now I'm curious if it is suspension/driveline/brake related.

diyer2 · July 2, 2019

Driveshaft?

Bent rear axle?

Had a vibration and it was the driveshaft.

Also seen a bent rear axle cause this.

Jack it up and put it on jack stands.

Run it and watch the driveshaft and wheels.

bcrooms · July 2, 2019

21 minutes ago, diyer2 said:

Driveshaft?

Bent rear axle?

Had a vibration and it was the driveshaft.

Also seen a bent rear axle cause this.

Jack it up and put it on jack stands.

Run it and watch the driveshaft and wheels.

I'm gonna have the U-joints changed as well.

bcrooms · July 26, 2019

An update: mechanic had time to look over a few more things as we were able to throw another Check Engine Light. Misfire on Cylinder 3 only while having the throttle wide open...

He changed the EGR valve....some improvement....said to run cleaning agents through the fuel system several times and it may clear itself up since we had to change the fuel injectors previously.

Also, the front rotors and rear drums were beyond needing replacement so that was done.

May be doing a shock replacement as well to smooth out the ride.

According to him, the truck has improved while he has had it for about a week.