30 replies to this topic

[ZR2MudSlinger]

this has been going on since October last year and has continually gotten worse, and I am to the point where its driving me insane going down the road. I started noticing a thump in the Passenger front end so i took it the shop i normally go to. $500 dollars later after they replaced my entire upper control arm and the lower control arm bushings it still does it, as soon as i left the shop i noticed the thump so i pulled a u-turn and went right back to the shop. The Mechanic who worked on it got in and rode with me and told me it was Tire Noise. So I told them I didnt go there to be told it was tire noise after they did 500 dollars worth of work and did not fix the problem. That escalated into a big argument which led to me not ever going back there again. So February comes along and I replace all four tires after feeling a wobble in the rear end, both my rear tires had busted belts. Now after a fresh set of tires, its still thumps. As i speed up or slow down so does the thump. Its very noticeable right around 35 mph and you can hear it while standing outside and the truck rolls past you, had a friend coast by me in a parking lot yesterday.

I have jacked the truck up and pushed and pulled on random suspension parts and everything feels fine, the cv has barely any play to it at all, the front drive shaft has a little bit of play at the differential and thats it, everything else is tight. My ball joints are in amazing shape according to the guy who did my alignment two weeks ago after getting my tires and even that guy told me everything else seemed fine, my truck holds and alignment. So i am stumped, anyone got any clue or direction I should look in? I know its hard to say without hearing it yourself but I need help. You can also feel the thump inside the cab under your feet in the passenger floorboard, I dont feel it on the driver side. The best way i know how to describe the thump is that it sounds like a huge knot in a tire going doing the road. Thanks

[mustash29]

Definately confusing.

New tires so that rules them out.

Tire guys would have probably noticed if you had a bent rim.

Have you tried rotating the new tires to see if the problem stays on the RF? Maybe it is a bent rim or badly balanced tire.

Bent / warped rotor? Can you put it up on 4 jack stands or a lift, put it in 4wd and watch all 4 tires spin? Look for things wobbling, like the tire, rotor, CV shaft, etc.

Bad shock on the RF? You could swap the LF & RF shocks to see.

Bad T bar crossmember bushing on the right? My 91 Sonoma had the old style T bar crossmember mounts. When one of them was bad it allowed the crossmember to float around inside the frame rails. Any little bump sounded like a midget on steroids was beating the shit out of the floorboard with a BFH.

Bad hub? But if that was the case the tire or allignment guy probably would have noticed it too.

[chrisxj]

i had the same problem check you torsion key the could be unloading and loading causeing the thump inside were the keys tuck away that solved my issue

[97chevy]

I recently had a thump, thought it was a ball joint, but nothing was loose. It ended up being a loose control arm. The cam bolts were real loose.

[ZR2MudSlinger]

i forgot to mention the rims were rotated front to back to rule them out as well.

[ducksface]

After spendinbg that money, you're going to hate this; it was my HOOD doing it. Yes, I could feel it all over the truck, yep, it felt like something 'jumpeda half inch or so, Yes it felt just like it was under the passenger floor. I opened the hood, shook the shit out of it and tightened the bolt, no more noise.

It had been drivng me nuts. i would have sworn I had a torsion key screwing up.

[ZR2MudSlinger]

After spendinbg that money, you're going to hate this; it was my HOOD doing it. Yes, I could feel it all over the truck, yep, it felt like something 'jumpeda half inch or so, Yes it felt just like it was under the passenger floor. I opened the hood, shook the shit out of it and tightened the bolt, no more noise.

It had been drivng me nuts. i would have sworn I had a torsion key screwing up.

i will give that a shot tomorrow, couldnt hurt anything. if anything just to rule it out i might take the hood off and drive around the block.

[ducksface]

I got the information from someone on here. The noise was freaking me out. the poster was right, it was my hood. he said he spent a shit-load chasing it down.

[ZR2MudSlinger]

i have gone beyond a shit load, i am about a grand into this thump

[IchBinGott!]

I had the same problem when I would stop, or take off, sometimes during turns. Felt exactly like what you're describing, but from the driver's side.


Turns out it was the door hinges. Soaked them in WD40 and it went away for a little while. Cleaned it up again and used some lithium grease that was laying around, hasn't done it for the last 6 months or so.


I only figured it out when I had the door open, and a rather large person got in on the passenger side. The truck made the same noise. I made him get in and out like 4 times

[Postmond]

Have you checked for the infamous cracked frame around the control arm mounts?

[ZR2MudSlinger]

I had the same problem when I would stop, or take off, sometimes during turns. Felt exactly like what you're describing, but from the driver's side.


Turns out it was the door hinges. Soaked them in WD40 and it went away for a little while. Cleaned it up again and used some lithium grease that was laying around, hasn't done it for the last 6 months or so.


I only figured it out when I had the door open, and a rather large person got in on the passenger side. The truck made the same noise. I made him get in and out like 4 times

i just wd-40'd the doors a few nights ago after a terrible screech so i know thats not it. thanks though

Have you checked for the infamous cracked frame around the control arm mounts?

i havnt but, i figured the guy who did my alignment would have noticed something?

[ZR2MudSlinger]

i took my hood off today and drove around the block and it still thumped, i am stumped....

[IchBinGott!]

Maybe your truck is challenging you. You need to make a bigger thump. Get out a mallet and just start hitting suspension parts. Eventually, the thump will go away.

[ZR2MudSlinger]

well i am starting to wonder.........

it might be my rear end. I made a right turn tonight at about 30 mph and it whined in a low pitch and made an oscilating noise, so i am wonder if its one of the shafts in the rear axle. I made a sharp left turn afterwards and no thump or whine

[TrailTamer]

my friend's POS Lexus did the same kind of thumps that's related with speed. it ended up to be frozen caliper sliding pins holding the pad tight on horrible rusted, unevenly worn rotors which made it to thumps pretty bad. new pads and a bit of work on cleaning up the sliding pins, it works like new again.

I'd check brakes.... I means pull the tire off and get the caliper & rotor off to inspect carefully.... inspect the wheel bearing while you're there....

I'd disagree with others whom said to check for something else that's not rotating as the truck moves as you said the thumps speeds up as you go faster... which pretty much tell me its with SOMETHING thats rotating... not a hood hinge or door hinge or so... also it's not bad idea to check the rear end too as i had experienced where the noises appeared to be coming from FRONT of the vechicle but ended up to be from somewhere in the REAR of the vehicle!

[ZR2MudSlinger]

i will give that a shot Trailtamer. I just had surgery on my arm and i am kind of immobile at the moment but it has been forever since i have had brake work so it very well could be that. If i dont find anything I hate to say it but i am going to a dealership repair shop and get an estimate on what it will cost to fix the thump and then do it myself based off of the estimate diagnosis

[ZR2MudSlinger]

well after my last post i went back to the shop and they told me that after they replaced the CV that the thump was still there. So they gave me a new CV for free, told me no charge since the old one was still good. Now the bad news is that they told me some battery acid leaked onto my 4x4 engage line and melted the rubber and made the wires inside rust together, my front end was apparantly locked in but not in 4 wheel drive if that makes sense, so now they are replacing that line to see if they can un-engage the front end.


What i dont get is how my front end can be engaged but the front wheels dont spin, i jacked it up and put it on jack stands so it was off the ground, had my dad get in an go through 2HI,4HI, and 4LO and everything worked fine.

[Gibbles]

After spendinbg that money, you're going to hate this; it was my HOOD doing it. Yes, I could feel it all over the truck, yep, it felt like something 'jumpeda half inch or so, Yes it felt just like it was under the passenger floor. I opened the hood, shook the shit out of it and tightened the bolt, no more noise.

It had been drivng me nuts. i would have sworn I had a torsion key screwing up.

this.

I started to hear a bad thumb while hunting, but I thought it was my ball joints... and it slowly got worse.

I finally got the washers from my GM dealer and had them print out an instruction sheet from the KB.

took a few minutes to install, and everything is nice and quiet now.

[ZR2MudSlinger]

had a few friends come over and we jacked my truck up and put it on cinder blocks, put it in 4wd and made the wheels spin at 15 mph. the noise is coming from behind my wheel bearing between the bearing and the differential. Both shops pulled my wheel bearing and said it was basically brand new. What else is behind that bearing?

edit: BTW we diagnosed this with a stethoscope

Edited by ZR2MudSlinger, 08 April 2011 - 09:38 PM.