# '99 GMC Sierra (New Body Style): popping noise in front end



## H2OK9 (Jun 28, 2002)

Hey yall, got a Texan here who seldom sees snow, but yall have one of the best GM threads around. I have a question that maybe someone can help me with.

I have a '99 GMC Sierra (new body style) 4X4 Short Bed, Extra Cab, 3 Door. Ocassionally when I start to move, from a complete stop, I can hear a popping noise from the front end. I can sometimes hear the noise when driving slowly down a bumpy road or turning on bumpy terrain. Everything under the truck seems tight. 

I have 265 75 16 Cooper STT tires, they are fairly aggressive, but I don't think that they are the problem. All help is appreciated.

Thanks a lot,

Shane


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## Alan (Mar 2, 2000)

Just one sound or several of them? Pop? or Popopopop?


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## H2OK9 (Jun 28, 2002)

Sometime it is just a single pop, and often it is a couple of pops. Never much more than two; three at the most. Also, when it does pop or knock, I can feel it in the steering wheel.

Shane


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## plowking35 (Dec 21, 1999)

I think that the sound is just the normal groans from the torsion when under a load.
Dino


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## ceaman (Sep 19, 2001)

Might just be the slap of the brake shoes durring takeoff. 
(Might not be too)


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## Alan (Mar 2, 2000)

Reason I asked is that I've had shocks blow out internally and make a noise as the suspension shifted on acceleration. But never anything you could feel in the steering, so much for that brainstorm.


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## H2OK9 (Jun 28, 2002)

The truck has Rancho shocks on all four corners. I'm hedging my bet towards the torsion bars. I suppose I'll just wait and see if it gets really bad.

On another subject, has anyone measured the bottom edge, center, of the wheel wells to see how high your pu sits? Mine is 37" on each side in the rear and 36 1/4" in the front. I have 265 75 16 tires on it and I'm considering 285's.


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## 1500HD (Jun 1, 2002)

The noise is coming from the steering shaft. Where two sections are slip-jointed togther, they rap against each other when you hit a bump or jar the truck.
GM has a service bulliten out on it, their fix at this time is to pull the shaft and re-grease it with a special service kit. We've done a couple at our shop that were out of warranty.


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## H2OK9 (Jun 28, 2002)

1500HD or anyone else,

How big of a job are we talking here? Is this something that I would be able to do or does it require some special tools? Also, what is included in the service kit? Thanks in advance.

Shane


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## 1500HD (Jun 1, 2002)

H2OK9,
It's not a big job at all. Just have to remove the intermediate shaft from the steering column, (a couple bolts) then put a plug in one end and shoot some grease into it, then reinstall. The service kit contains the grease and the plug. Fairly cheap too I think.


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## H2OK9 (Jun 28, 2002)

Thanks, I'll have to take a look. I have always been a Ford man, this is my first GM product. Once again, thanks for the help.

Shane


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## Foz (Mar 27, 2001)

I would take it to your dealer & have them check the torsion bar mounts. If the POP happens when you turn or are on rough terrain it is most likely the mount. We run 2 GMC 2500HD, no problems with them, but I have broken the mounts on 3 previous trucks.


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## H2OK9 (Jun 28, 2002)

The popping usually happens when I'm driving through the yard or come up on a rough section of pavement. I have also noticed it when I am stopped and let the truck roll forward a little then press the brakes hard. 

Shane


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## Snoworks (Jan 22, 2002)

H20K9

Did you ever fix the poping noise, if so lets here about it. I am currently having the same problem with my 1998 Sierra 3/4 ton.
Same problems as you discribed, to the tee!

CGB


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## H2OK9 (Jun 28, 2002)

No, I didnt get the noise fixed yet. I'm just trying to ignore it and hoping thtat it will go away......fat chance. I believe that it is the torsion bar, but I'm not sure. If you get yours fixed before me, let me know.

Shane


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## Knightcrawler (Dec 23, 2001)

*popping noise*

just a thought here but did anybody check the upper and lower ball joints, they make this exact sound you are discribing.


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## H2OK9 (Jun 28, 2002)

I just put new tires on the truck 285's and the noise seemed to go away for awhile or at least diminished some. Then it began to creep back in and is doing the same thing again, maybe even a little more. 
What I really need to do is just take it in and have it looked at. Geeze, what a procrastinator I am.

Shane


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