truck "wanders"

chadlyt · April 1, 2005

I've seen this porblem advance more lately and i hate to think exactly what it might be...

when i am going down the road, my truck seems to "wander" and it's harder to control around corners higher speeds. the steering wheel is also tighter than it used to be, it's much harder to turn.

any ideas where i should start looking?

a few stats:

2001 2500HD 6.0L EC/SB 4x4 83K miles.

month old Rancho RS9000X shocks

265x76xr16 REVO's

16x8 Eagle alloy rims with 4" backspacing

no fluid leaks, power steering lines look ok and has not needed to be topped off.

torsion bars not cranked

I've been thinking maybe front wheel bearings, but i dont want to waste my time until i hear back from you guys.

If i've left anything out that you may thing might help, tell me.

Thanks a ton guys!

Mule · April 1, 2005

You should look at the Pitman and Idler arms. Also the idler arm bracket, ball joints, and tie rods.

I am not saying replace these, but if they are worn, they could contribute to the symptoms you describe.

Freyguy · April 2, 2005

It almost sounds like worn pitman/idler arms, but I'm not sure about the tight steering. Mine was wondering and unresponsive, and the pitman/idler upgrade sure helped.

The way to tell is to get under the truck while somebody turns the wheel stop to stop and see if your centerlink goes up or down. Mine was loose when hit and would go up at the end of each turn. If this is what you need, fabtech sells an upgrade kit with beefy pitman and idler arm replacements, and a new longer steering stabilizer that prevents it from happening again. It drives soo much better with this kit, but the only downfall is that you loose a little bit of your turning radius. The kit is only about $250+S&H when stock replacements without the stabilizer would run close to $200.

PeterbiltChrome · April 2, 2005

get your air pressure up and see if it steers easier... easy to check, so its not too much trouble to experiment...

Haulin' 8.1 · April 2, 2005

Two things you can do to check. Get the front end off the ground with a jack and stands.

1. Hold each tire/wheel at 12 and 6 and forcefully try to rock it by pushing in with one hand and pulling out with the other back and forth. It there's any perceptable freeplay it's a bad bearing/hub assembly. *make sure the spindle isn't moving if so*.

2. Have someone slowly *really slowly* turn the wheel from lock to lock with the engine off. Listen and look at all the steering linkage joints for binding. If something is frozen it will have jerky movement and make clicking or popping noise in its travel.

Vernon

71GMC_3/4T · April 2, 2005

To add to Vernon's excellent troubleshooting steps:

Have someone wiggle the wheel back and forth slightly. Look and feel the tie rod ends and where the drag link attaches to the steering arm. If you see or feel any play, that might be part of your problem.

You say the steering wheel is tighter than it used to be? Bad wheel bearings shouldn't cause that. More likely something binding, bad steering box, bad idler arm or something like that. Have you greased all 11 zerks on the front end with a good quality chassis grease?

snoman · April 3, 2005

If you are running a 4 inch offset back spacing you are putting a lot of load and strain on front end that it was never designed for and handling can be strange. The solution may lay in adding additional positive camber over stock (about 1.5 degrees or so to shift load center more inboard) and check toe in closely and measure it yourself from front to back and tell me what you find. Improper caster angle can cause a vague road feel too.

8100HD · April 4, 2005

Sounds like pitman and idler arms are shot..which is an all to common problem with the HD's, also if your steering is getting harder you may have a hydraboost going bad, which will also cause braking to be harder also, again not an uncommon problem with these trucks.

Wingnut · April 4, 2005

1. Hold each tire/wheel at 12 and 6 and forcefully try to rock it by pushing in with one hand and pulling out with the other back and forth. It there's any perceptable freeplay it's a bad bearing/hub assembly. *make sure the spindle isn't moving if so*.
Vernon

<{POST_SNAPBACK}>

Wouldn't bad balljoints also exhibit this same freeplay?

snoman · April 4, 2005

1. Hold each tire/wheel at 12 and 6 and forcefully try to rock it by pushing in with one hand and pulling out with the other back and forth. It there's any perceptable freeplay it's a bad bearing/hub assembly. *make sure the spindle isn't moving if so*.
Vernon

<{POST_SNAPBACK}>

Wouldn't bad balljoints also exhibit this same freeplay?

<{POST_SNAPBACK}>

Bad ball joints will cause wander but not increased steering effort. With offest wheels you increase relative load on front end parts (bearings , joints and rod ends) and alter the alignment geometery as well as require increased effort to guide it and road forces transmitter back to suspension are amplified as well. More camber (the angle of tire tipping out at top) will tend to offset some of extended load on front from offset but there is no magic bullet here as the leverage for increased offset is overpowering the designed steering loads and will amplify and play in steering.

Haulin' 8.1 · April 4, 2005

1. Hold each tire/wheel at 12 and 6 and forcefully try to rock it by pushing in with one hand and pulling out with the other back and forth. It there's any perceptable freeplay it's a bad bearing/hub assembly. *make sure the spindle isn't moving if so*.
Vernon

<{POST_SNAPBACK}>

Wouldn't bad balljoints also exhibit this same freeplay?

<{POST_SNAPBACK}>

Yes they can, note the note *make sure the spindle isn't moving if so* in your quote. Ha, kinda rymes.

Another thing, on the Hydroboost. Hydro(hydraulic)boost is with the diesel engine, not the gassers. It's simpler, less costly, and more reliable to use vacuum to boost brake pressure but diesel engines are not air throttled so they don't pull much if any vacuum. He's got a 6.0, so no hydroboost.

On a side note the fact that diesels freewheel at all times, that is don't have to build any power to overcome cylinder filling under vacuum, is one of the major reasons they generate better fuel efficiency.

Vernon

chadlyt · April 4, 2005

Dang guys! thanks for all the replies!

I'll be looking at this tonight seeing the wife gives me a few minutes to look things over. too bust these days.

I'll check out everything mentioned.

as a side note, it is too bad i didn't research the backspacing more closely. The rims i have, eagle alloy 058's, only come with a 4" back spacing...I have been in the market for new rims, so maybe now is the time to really start looking.

tonight if i get under there, i'll check these things out, take a few pics if there is anything I question, or if there is anything worth taking a pic of.

thanks for the help and post more if you can think of anything else!

Thanks!

snoman · April 4, 2005

1. Hold each tire/wheel at 12 and 6 and forcefully try to rock it by pushing in with one hand and pulling out with the other back and forth. It there's any perceptable freeplay it's a bad bearing/hub assembly. *make sure the spindle isn't moving if so*.
Vernon

<{POST_SNAPBACK}>

Wouldn't bad balljoints also exhibit this same freeplay?

<{POST_SNAPBACK}>

Yes they can, note the note *make sure the spindle isn't moving if so* in your quote. Ha, kinda rymes.

Another thing, on the Hydroboost. Hydro(hydraulic)boost is with the diesel engine, not the gassers. It's simpler, less costly, and more reliable to use vacuum to boost brake pressure but diesel engines are not air throttled so they don't pull much if any vacuum. He's got a 6.0, so no hydroboost.

On a side note the fact that diesels freewheel at all times, that is don't have to build any power to overcome cylinder filling under vacuum, is one of the major reasons they generate better fuel efficiency.

Vernon

<{POST_SNAPBACK}>

Info you, Hydro boost is used on a lot of gassers (my 2000 K3500 gasser has it) and I think you will find the current 2500HD's have it to regardless of engine type.

Also a diesel takes more power to motor ofver or spin with full cylinder pressure than a gas engine with vacum and the reason a oil burner can get better MPG is because of the higher compression ratios and the increased thermodynamic efficency it yeilds and the higher heat/energy content of fuel (it has about 15% more energy per gallon) not because of vacum pumping losses. Also Diesel uses direct injection which limits fuel loss through system but gas engines will have direct injection in main stream on another 3 to 5 years which will boost MPG 15 to 20 % with all things being the same otherwise and increase power some too and it will also allow for increased compression ratios (which improve thremodynamic efficiency) without preigniton with current fuels as injecting the fuel direct into cylinder cools mixture and retards knock. When DI gas engines become main stream the diesel advange will be a lot smaller and diesels are dirtier than gassers to and very rich in NOx polution and CO2 output and the more you boost them the worse they get.

8100HD · April 4, 2005

Haulin', are you positive about the hydroboost...it is quite uncommon to find a GM these days that does not have it...they have been using it for years on everything from the Buick Grand Nats. to the new 1/2 tons...I know that both my HD and the wifes '04 Tahoe have hydroboost...this is not just reserved for the diesels.

Haulin' 8.1 · April 5, 2005

On the hydroboost, I didn't realize they were putting them on gassers nowadays. I work on a bunch of trucks and I've yet to see it on any thing but a diesel but if you guys say that you've seen them I take your word for it . At least you haven't seen any deisels with some sort of vacuum pump and booster combination have you?

Snoman, on the diesel/gasser thermodynamics I agree with you completely. I was being very simplistic and discussing the diesel alone, not trying to compare them to gassers. I know it wouldn't work this way but imagine how much milage would be affected if the diesels had to suck air and compress it as much as they do. That was my point in the higher efficiency of the diesel as an internal combustion engine. Not that it was the only reason, like I said just one of them. Just imagine how much better fuel efficiency my 496 would get if it could run unthrottled and still burn a small amount of fuel at idle or just cruising.

Vernon