03 Suburban LT Steering Issues, Wandering and Wobbly and Loose

[houstontaylor]

I would say you need new shocks if they are the originals. Worn out shocks can bounce you all over the road. On my 2003 Chevy Tahoe with more miles than yours I've replaced the shocks twice since the originals.

 

[Fless]

if its saying service 4wd, you got codes. normal scanner wont pick these codes up. need a abs scanner. even if the abs and brake lights are not lit up, you likely have a code (or 5 or 6) stored.

^^ THIS. A scanner that will read the 4wd codes will also show live data; in addition to the codes you can view live data and compare the commanded mode to the actual mode (2hi vs AUTO, for example). With the description you gave I would suspect the transfer case encoder motor to need a new internal range position sensor, or a new encoder motor. But the codes and live data would confirm.

Range position sensor:

 

[Meathead16]

Have you done anything to the rear? It's surprising how much the rear track bar and control srms can affect the control and stability and general feel of the ride.

How are your torsion bar mounts?

I have the same wheel hop/skip/bop on near full lock turns. I figured it was an alignment issue. Mine does leaves black tire marks everywhere it goes too. maybe the alignment needs checked again.. Firestone is a sketchy place to go. Never had anything but problems with them.. last straw was when they stripped the lug nuts on my moms car and the tire almost came off while driving. Never went to the same store twice so I can't help but think it's a top down compqny culture type issue.

 

[GMT800Man90]

^^ THIS. A scanner that will read the 4wd codes will also show live data; in addition to the codes you can view live data and compare the commanded mode to the actual mode (2hi vs AUTO, for example). With the description you gave I would suspect the transfer case encoder motor to need a new internal range position sensor, or a new encoder motor. But the codes and live data would confirm.

Range position sensor:
View attachment 446651

I just looked at everything on my scanner. Live data, actuation tests. There were no codes. Watching live data while switching through all the modes and everything looks great. Goes into each mode just fine. And out just fine.

 

[Fless]

I just looked at everything on my scanner. Live data, actuation tests. There were no codes. Watching live data while switching through all the modes and everything looks great. Goes into each mode just fine. And out just fine.

Well, I can assure you when the Service 4wd message is on, there will be at least one code. My eureka moment was when mine was switched into 4hi, in a few seconds the scanner would indicate the AUTO mode. The dash switch still indicated 4hi but it wasn't right.

 

[GMT800Man90]

Well, I can assure you when the Service 4wd message is on, there will be at least one code. My eureka moment was when mine was switched into 4hi, in a few seconds the scanner would indicate the AUTO mode. The dash switch still indicated 4hi but it wasn't right.

Yeah that's what I thought. But there were zero codes. Only one I've had was an evap code that comes on because my filler neck has a hole in it and leaks fuel if you fill it fast.

My scanner isn't one of the crazy expensive ones, but was still a $600 scanner and I can read and see all codes all modules and do all the bi directional tests and stuff. Everything looked great. Everything was switching fine. Never threw a code even when the service 4wd came on.

 

[Fless]

Again, if the Service 4wd message shows up on the DIC, there's a code at that time. The code triggers the message. You may need to verify that your scanner can read those codes, including Pending and History codes for the 4wd system.

 

[GMT800Man90]

Again, if the Service 4wd message shows up on the DIC, there's a code at that time. The code triggers the message. You may need to verify that your scanner can read those codes, including Pending and History codes for the 4wd system.

And I've done that. My scanner can do pretty much everything. It's not a cheap one. There are zero codes. Trust me. It'll throw service 4wd but the truck will drive just fine. Live data shows everything switching like it should, goes in and out of the different modes just fine. I pulled the grounds off, cleaned them and put new bolts on them and fluid filmed them since i live in Ohio. It didn't change anything that I've noticed. But no, in 2wd the truck is not stuck in 4wd. There are zero codes. None pending. None history. None current.

 

[Tonyrodz]

And I've done that. My scanner can do pretty much everything. It's not a cheap one. There are zero codes. Trust me. It'll throw service 4wd but the truck will drive just fine. Live data shows everything switching like it should, goes in and out of the different modes just fine. I pulled the grounds off, cleaned them and put new bolts on them and fluid filmed them since i live in Ohio. It didn't change anything that I've noticed. But no, in 2wd the truck is not stuck in 4wd. There are zero codes. None pending. None history. None current.

Maybe start fresh and disconnect the battery for awhile, also touch both battery terminal connections--the vehicle harness connections--this should clear out any codes. Then reconnect and take it for a ride, going in and out of 4wd. See what happens.

 

[NELLY1947]

I've got an 03 Suburban LT 4WD with problems that I just can't seem to figure out. So I'm hoping someone here can point me in the right direction.

Truck has 243k. I replaced a ton of things trying resolve this wandering, wobbling and loose feeling issue. And it's still all over the road and hard to control most of the time. The following is what I've replaced with brand new quality components.

Tires
Upper and lower ball joints on both sides
Outer tie rod ends
Pitman arm
Idler arm and bracket
Hub bearings
Sway bar links
Upper intermediate steering shaft and steering column bearing
Adjusted the steering box
Tightened the torx screws under the steering column covers
Alignment

It seemed better for about 10 miles and then has been the same since. I have absolutely no idea what else it could be. I just jacked it up and checked play and there is no up and down or side to side play. Truck has the stock 16" alloys on it.

Any ideas on what I need to check next? It has the stock shocks on it and came with the factory autoride suspension but has not worked in a long time and I've bypassed the system. But the factory air shocks front and rear are still on the truck. This is the 5th GMT800 I've owned and none of the other 4 have driven like this.

Thanks y'all.

Couple ideas ( and i might be in left field)
I had a 2016 3500 Denali P/UP..Was all over the road. In the steering colum in the engine compartment there is a 5$ white plastic bushing. They found it after changing almost the whole front end. They asked me if i use the steering wheel to pull myself into the truck. And that is what caused it. I only had 20,000 mikes at the time.
2nd idea. On my 2019 Yukon the Dealer hit a good pot hoke while on a test drive but they said they checked everything including the balancing. but every so often the thing would shake like crazy. (Not all the time) . So finally I took all the rims to a shop and they found 3 out of the 4 were out of round every so slightly. And this caused it. Cause the shaking would start when the tires were hot. So they would start pulling. Went through a lower ball joint,tie rod and blamed the tire manufacturer for 3 sets of tires.

 

[GMT800Man90]

Maybe start fresh and disconnect the battery for awhile, also touch both battery terminal connections--the vehicle harness connections--this should clear out any codes. Then reconnect and take it for a ride, going in and out of 4wd. See what happens.

Oh yeah I did that too. It didn't change anything unfortunately. It's just one of those things that's driving me insane. Because I've had 5 of these trucks and this is the only one that's been like this. I've had an 01 Yukon XL, two 04 Suburban's, 04 Sierra and now this 03 Suburban. Every other one had the same kind of mileage except my 04 Z71 Burb had 330k. They all drove great and had no issues like this. It's just super strange that I'll throw it in auto 4wd or 4lo and start driving and it pops up service 4wd but in auto 4wd it'll drive and shift just fine. In 4lo it won't shift. 4hi it doesn't throw the message and is just fine. When service 4wd comes up, it won't let me change the selection. I have to shut the truck off and turn it back on and then I can switch it. And when I go in 4hi or 4lo you can hear it switch and clunk and switching back to 2hi from 4hi or lo you can hear it switch and clunk again. Putting in auto 4wd you don't hear anything

 

[Tonyrodz]

Oh yeah I did that too. It didn't change anything unfortunately. It's just one of those things that's driving me insane. Because I've had 5 of these trucks and this is the only one that's been like this. I've had an 01 Yukon XL, two 04 Suburban's, 04 Sierra and now this 03 Suburban. Every other one had the same kind of mileage except my 04 Z71 Burb had 330k. They all drove great and had no issues like this. It's just super strange that I'll throw it in auto 4wd or 4lo and start driving and it pops up service 4wd but in auto 4wd it'll drive and shift just fine. In 4lo it won't shift. 4hi it doesn't throw the message and is just fine. When service 4wd comes up, it won't let me change the selection. I have to shut the truck off and turn it back on and then I can switch it. And when I go in 4hi or 4lo you can hear it switch and clunk and switching back to 2hi from 4hi or lo you can hear it switch and clunk again. Putting in auto 4wd you don't hear anything

Think the 4wd switch could be bad? The one on the dash with the 4wd buttons. They do occasionally go bad.

 

[GMT800Man90]

Think the 4wd switch could be bad? The one on the dash with the 4wd buttons. They do occasionally go bad.

I don't think so because when you switch into 4lo and back out of 4lo you hear the clunk and switch. I don't know if it's supposed to clunk going into auto 4wd. From what I read it locks the front axle but doesn't engage until it detects slip. Putting it from 2hi to 4hi there's no noise. I haven't had to use 4wd in one of these trucks since winter of 22, so I don't really remember. I kept my Sierra in auto 4wd and never had an issue

 

[89Suburban]

What about the jounce stops are they in good condition?

 

[Fless]

I don't think so because when you switch into 4lo and back out of 4lo you hear the clunk and switch. I don't know if it's supposed to clunk going into auto 4wd. From what I read it locks the front axle but doesn't engage until it detects slip. Putting it from 2hi to 4hi there's no noise. I haven't had to use 4wd in one of these trucks since winter of 22, so I don't really remember. I kept my Sierra in auto 4wd and never had an issue

It shouldn't "clunk" going into AUTO. Each mode change should produce a short "whirring" sound, if it's anything like mine.

In AUTO the front diff is NOT engaged until rear wheel slippage is detected; that's when the front diff actuator is commanded to engage the diff. But the transfer case is spinning the front prop shaft at the appropriate speed so when the diff does engage it will be relatively smooth. That's why the various speed sensors are in the drivetrain.

 

[GMT800Man90]

It shouldn't "clunk" going into AUTO. Each mode change should produce a short "whirring" sound, if it's anything like mine.

In AUTO the front diff is NOT engaged until rear wheel slippage is detected; that's when the front diff actuator is commanded to engage the diff. But the transfer case is spinning the front prop shaft at the appropriate speed so when the diff does engage it will be relatively smooth. That's why the various speed sensors are in the drivetrain.

Yeah it doesn't clunk going into auto. It's been awhile since I've had to mess with these trucks and 4wd so I'm a bit rusty on it.

However the other day we started driving it, indicator light showing 2wd and the service 4wd light came on. I haven't scanned it yet because I've been super busy. But one thing that's concerning to me is when it's in auto or 4wd, and I push the 2wd button, the indicator light immediately goes solid. Doesn't flash like it should then go solid. So that's a bit concerning. And the crow hopping when sharp turning is a concern. But again I've had zero codes and the live data shows everything working as it should.

 

[GMT800Man90]

It shouldn't "clunk" going into AUTO. Each mode change should produce a short "whirring" sound, if it's anything like mine.

In AUTO the front diff is NOT engaged until rear wheel slippage is detected; that's when the front diff actuator is commanded to engage the diff. But the transfer case is spinning the front prop shaft at the appropriate speed so when the diff does engage it will be relatively smooth. That's why the various speed sensors are in the drivetrain.

Alright Fless. Scanned it and it did FINALLY throw codes.

C0300-Rear propshaft speed sensor malfunction
C0305-Front propshaft speed sensor malfunction
C0374-General System Malfunction

 

[GMT800Man90]

It shouldn't "clunk" going into AUTO. Each mode change should produce a short "whirring" sound, if it's anything like mine.

In AUTO the front diff is NOT engaged until rear wheel slippage is detected; that's when the front diff actuator is commanded to engage the diff. But the transfer case is spinning the front prop shaft at the appropriate speed so when the diff does engage it will be relatively smooth. That's why the various speed sensors are in the drivetrain.

The only code it immediately throws again is the C0300 rear propshaft speed sensor malfunction. I watched live data this morning and neither front or rear propshaft is reading any rpm speed. It's just strange that it's never thrown the service 4wd unless I was in auto 4wd, but now it throws it anytime I drive