Suburban wandering, Hit bump and steering seems to turn?

[Jimmy John]

Bought a 2004 Suburban 2WD 1500 E85 220,000 miles and it has a few issues. One is lots of extra steering required to stay in lane on freeway. If the road is flat with an slight angle I can just hold wheel to the left a little and its not to bad to drive but if I need to change lanes or the banking changes then I have to work the steering wheel a lot. I jacked up the front end yesterday and tried to check for slop in all the joints. To a novice like me it seemed to be pretty tight in the joints. The biggest then I ran across was when I turn the input shaft on the steering gear or box as some people call it I noticed a few degrees of turning the input shaft before the pitman would move. I search the web quite a bit and even looked at GM's service manual and can't find any info on how much slop in the steering gear is normal. The pitman itself seems to be tight to the gear the shaft the pitman is on seems like it might move ever so slightly if I rock the input shaft back and forth with my hand. Tried the allen screw and nut on top of the steering gear to take out the slop but did not noticed any change with that. Anyone have an idea? Thanks.

 

[SnowDrifter]

Remove any skid plates if you need to so you can get a clear look underneath

Have a friend wiggle the wheel back and forth semi-firmly with the car off. Climb underneath and feel the axle where it goes into the knuckle(wheel bearing), the outer tie rods where the connect to the knuckle, inner tie rods where the connect to the center link, pitman arm where it connects to the center link, idler arm where it connects to the center link, and idler arm where it connects to the bracket.

None of those should have freeplay. You'll need to get your hands dirty for this. The nerves in your fingers are more sensitive than your eyes and you'll feel freeplay even if you can't see it

While you're under there, check to make sure your center link is oriented properly. The droops for the tie rods should be oriented down and towards the rear of the vehicle. Without knowing the vehicle's history it's possible it was put on the wrong way at some point. It'll cause all sort of bizarre steering issues... I had chased mine down to that a few threads below this one

See orientation here:




Next grab a jack and lift the front end up via the lower control arms - you want to jack from as close to the outside is possible but NOT on the lower ball joint. The idea here is to get the weight off the wheel but have the suspension as close as possible to it's neutral position. Grab your friend and have him try to lift the tire up as well as try to camber it in and out. Feel the upper and lower ball joints as well as relationship between the axle and knuckle(wheel bearing) for any freeplay. Do the same to the other side.


From there, let the car down and visually inspect where the control arms secure to the frame. There shouldn't be any cracks or missing material. Have your friend jounce the car upside down as well as shove it side to side while you feel the bushings. If that checks out, up in the car and give it a few gas-brake-gas-brake treatments at walking speed. make sure the front wheels are steady and don't move forward / backward indicating there to be a control arm bushing issue.




From what you describe it sounds like your steering box is worn out. Mine had a small amount of play but I was able to adjust it out. I don't have any play in my steering. 1/4" adjustments in the steering wheel cause the vehicle to change directions accordingly. If I hold the wheel straight it goes straight. It's tough to get an idea of how these rigs *should* drive because so many have steering looser than a Kardashian ******



If everything I suggested checks out, I think it would be worth your time to see an alignment shop and get an idea of what all your steering angles are

 

[Larryjb]

What I learned about the center link (or relay rod) is that sometimes you cannot feel slop, but if it rotates up and down, the pitman and idler arms are shot. Maybe others are better at feeling sloppy pitman arms, but not me.

Given the cost of each, and the tie rods, I just replaced everything once I had it apart.

 

[Jimmy John]

Did some more testing. Tried the dry park test only thing out of the ordinary I could see was the idler arm would go up and down maybe 1/8". It only takes about 1" movement in the outer rim of the steering wheel for the wheels to start moving. On thing I did find was the front tires are 2 different brands and also different sizes. The left one is 265/70R17 and the right one is 265/65R17 that figures out to 1/2" lower on the right hand side. The suburban pulls to the right so I don't know if that jives with what the tire sizes would create or not. I guess I need to look for new tires and see what happens. I bought this thing for $1700 and if it looks like a money pit I was just going to unload it but some of these issues are had to diagnose without spending more money. Found a set of 2015 chevy truck wheels and tires but I read where the center bore on these wheels are 78.1mm vs 78.3 on the SUVs doesn't sound like much but I assume they won"t work. I don"t understand why GM went these route unless it was on purpose as that's only about .080 difference in diameter.

 

[Jimmy John]

Swapped the front and rear tires on the side with the smaller front tire to see what difference that would make. Drove to work which is about 3 miles back roads and 2 miles highway. Didn't seem to pull as much to the right as it did before. Also did not notice wandering as bad. One thing that was very apparent is a lot of clunking type noise and feeling in the steering even at times I thought to be smooth stretches of the road. I'm thinking I should look at the intermediate shaft I see talked about here a lot. I have this in my 03 Impala with 200,000 miles although it is very slight compared to what the Suburban sounds and feelings like. I see some people also replace what looks like a bushing but call it a bearing
Dorman 905-512 Cadillac/Chevrolet/GMC/Oldsmobile Steering Column Lower Bearings . Does anyone have experience with this and think the bearing is usually an issue?

 

[DansOtter]

While you're under there, check to make sure your center link is oriented properly. The droops for the tie rods should be oriented down and towards the rear of the vehicle. Without knowing the vehicle's history it's possible it was put on the wrong way at some point. It'll cause all sort of bizarre steering issues... I had chased mine down to that a few threads below this one

FOR REAL THO... I just traced my steering problems to that too. Had it aligned 6 different times at 3 different shops and no one caught it. I mean... it was my fault for putting it back in wrong BUT STILL.

Not my proudest moment. But damn glad it's fixed.