steering wheel pulling

[bl78ljb]

Ok, I have an interesting problem with the Suburban. At the moment I am a few weeks out of surgery on my hand so am relying on my shop (whom I trust and has always done an excellent job) to work with me on this. A few weeks ago my wife started to complain that the steering wheel was pulling to the right, I drove the truck and thought maybe a caliper sticking or a bad steering component (though it was just aligned a few months ago). It was due for an oil change anyway so brought it into the shop. They checked the calipers and they were fine, reviewed the recent alignment results (spot on no wear at that time) and the test drove it on the computer. Lo and behold they got a wacky reading from the steering position sensor. Replaced and told me good to go (they did a 15 mile test drive w/o problems). They also rotated the tires as they were due to be rotated. Drove it home and it started pulling hard to the left this time but harder than before. I brought it back and they found the pittman arm and the drag link to be on the outside edge of spec and figured with the 285s that maybe that was the issue so I told them to go ahead and replace them. Drove it home all was well steering felt tight. However, the next day (yesterday) out with the family it starts pulling again. The pull is an intermittent pull that tugs on the wheel as if someone is trying to grab the wheel from your hand and will happen a few times and then stop maybe for a few feet or a few miles. It also seems that this occurs when it is colder (yesterday it was in the 20s in the evening), and when I drove home from the shop it was in the 50s. This morning I had the truck plugged in overnight as it was to get close to 20F and I don't think we got winter blend yet and my wife said it only pulled once or twice all day. This is driving me nuts, especially since I can't really get our there and diagnose it myself. I figured someone here has likely had this problem before, but I can't find anything doing a search. To summarize thus far: new steering position sensor, pitman arm and brace, drag link and tires rotated; calipers and all other steering and suspension components checked out fine and alignment is spot on.

[bl78ljb]

Well, I see that no one else has any idea thus far either. Last time at the shop they replaced the solenoid on the steering box with a GM upgrade / replacement. So far, it has been much better but the pulling is still not gone 100% just much less frequent. My wife was driving the other day and it started pulling at 30MPH on a back road, she increased her speed and it went away and she couldn't reproduce it at 30MPH later in the drive. I had a mild pulling to the right with 4WD engaged in the snow today that went away after a few minutes. As we have tried more solutions it seems to become less frequent thus harder to finally fix. Any ideas?

[DennisG01]

Bad brake lines? They can fail on the inside and create a "check-valve". It certainly can create an issue where sometimes it's fine and other times it pulls. If the right brake line is bad, the truck will pull left as no fluid is pushed to the right brake.

[bl78ljb]

I had initially thought of that, but it never happens when braking. The other odd thing is this is not a pulling that is a steady pull it is more like someone is intermittently yanking the steering wheel to the left in a pulsating fashion. I have had other vehicles pull for brake and suspension issues and that is usually a steady pull that is corrected by turning the wheel the other direction. This pull may happen on a straight road with good pavement (important to mention for anyone who has been to rural Maine) maintaining a constant speed and all of a sudden it is like someone is trying to pull the wheel to the left, if you adjust your pressure on the wheel you can keep the wheel straight and the truck will not go anywhere but you can still feel the pull on the wheel that you have to compensate for.

[DennisG01]

Hmmm. OK, sorry - I misread your post. And here I thought "Hey, it seems they're all overlooking the obvious". That is a strange one (at least for me). Hopefully someone else can chime in. Do you think it could be as easy as low PS fluid (air bubbles)? Or just fluid that needs to be changed? Just guesses, though.

Ayuh, I certainly understand the rural roads in Maine. We have family in Augusta and cabins in Friendship (and Friendship Island) - I'm up there at least every summer. My grandmother has been going ever since she was a little girl - she's going on 87 now.

[joed]

I know you said you replaced the steering pos. sensor, but your description sounds very similar to my 98 when the sensor went bad. It was like the wheel got jerked - due to the sudden decrease in pressure.

Have you tried either pulling the fuse or disconnecting the sensor and seeing if that helps? That should help rule out that part of the system.

Joe.

[bl78ljb]

The shop also just replaced the solenoid with a fixed orifice as per the GM recommendations at the solenoid is NLA from GM due to just these problems. Since this the pull has only occurred twice. I had thought and hoped it was related to the steering position sensor or solenoid.

[More Power]

Might be the steering sector, but it's an expensive item to replace without knowing for sure whether it's the cause.

Jim

[bl78ljb]

I would imagine the only way to fix the sector is to replace the box - which is what I would prefer not to have to do if this might be something else! I assume there is a diagnostic for testing the sector? I was just thinking that with the changes that have been make making this less common could a failing PS pump cause such symptoms if it was intermittently not producing sufficient pressure? I have not noticed anything in the hydroboost, but this seems to never occur while braking.

[bl78ljb]

I uploaded a video to youtube of the wheel pulling. I was driving on up to a stop and then turning right. The road had a slight rightward curve in it. All leftward movement of the wheel was done by the truck itself. Granted while this was being recorded I allowed the wheel to go left, when this happens the leftward movement can be resisted but it does take some effort. Here is the link to the video. http://www.youtube.com/watch?v=_EahE6Zsr-E

Thanks for the comments thus far.

[bl78ljb]

Well, I finally got this problem solved. Actually it was fixed just before Christmas, but I wanted to give it some time to make sure it was fixed. As it turned out I was bringing the truck to the local dealer to have this evaluated, and on the way I had to make a right hand turn and heard a clunk then driving down the road I suddenly heard a loud snap and then banging. I knew immediately what was wrong - the right C/V shaft had snapped in half and after pulling over and checking it out that is exactly what happened. So, a tow to the dealer and a replaced front C/V shaft and no more steering problem. It is odd that there were never any typical C/V symptoms and the one clunk was the first indication of the origin of the problem. The mechanics response was "well I guess as bad as the joint was it could have caused a steering problem." Thanks for everyone's thought on this.