DG_Guy

I've a 2010 E550 I bought used with 30K miles. About 20% of the time I can take my hands off the wheel at either low or high speeds and it goes perfectly straight. The rest of the time it pulls to one side. I'm a bit confused as to why it only pulls occasionally instead of consistently.

I shopped for a used E550 for about 9 months. While doing that I saw several whose carfax showed the tires being balanced and rotated repeatedly every 500 or 800 miles. Way too often. I didn't know what that was about so I avoided those. Once I found mine, the salesman actually pointed out to me as I picked it up that it was pulling to the right a bit and I should bring it back in when I had time and they'd fix the alignment. I did that and then it pulled slightly to the left. Brought it back again, did another alignment and it's better but still pulls sometimes but not always.

I'm wondering now if this occasional pulling to one side is a quirk of the model and that's what I was seeing on all those carfax's. I think if you looked at my carfax now you'd see 2 tire rotation and rebalances within 600 miles juts like those other cars I saw.

Any ideas?

R-N

My 2012 E350 pull slight left, less so on very flat road. After reading around I think its a function of the wide flat contact area of the tires, staggered setup, geometry and suspension, etc. At normal road speeds there's no problem at all. Look for abnormal tire wear thats the best sign of possible alignment problems.

Also had a C coupe with similar issues. Dealer checked alignment and told me the same regarding that car's setup, wider tires, etc.

Arrie

The car pulling occasionally on both side most likely is not alignment problem. It probably is road condition problem.

It is easy to chek if you experience this on an interstate highway. Usually these roads (like most roads) are build with crown in the middle, i.e right side lane drains rain water to right, left side to left. Often changing to left side changes the pull to the left when it was right when driving on the right side lane.

Also, just driving on the right side lane can have pull on either side as the road surface has worn "grooves" and it depends on which side of the "slope" you are driving on.

But, if you have a completely flat road to test on and you have even tire pressures on each side on each axle and the car pulls different ways on different days then you have something loose in your steering linkage. Change under these conditions can only be from "backlash" in the system (assuming you have the same load condition in the car).

After numerous visits to the dealer take you car to an independent shop to check the alignment. It only cost ~$70 and if they find something wrong and correct it and after testing you find it fixed you can take the bill for the job to your dealer service manager. They might even pay for it.

DG_Guy

Thanks for the advice guys. I'll post if I learn more.

GoBlando

Does it only pull one way or another in the first 10-15 minutes of driving and then go away? Does it pull one way when you are first driving and then pull another after 10-15 minutes?

Check your tire pressures and make sure they are actually close to what they are supposed to be. In particular make sure the tire pressure match on both sides of the axle. The gas filler door has the cold tire pressure ratings. Keep in mind that when it says "add +4 psi for warm tires" it means completely warmed up like you have driven at highway speed for 10+ miles, not drove 2 miles to gas station in city driving.

For best possible setting, fill tires to gas door levels + 5 psi. Next, park car in a flat/level shaded area for several hours. When you return to the car, check all the tires and release air to get the pressure to match the cold values from the door. Now, drive the car for 15 minutes and then reset the TPMS memory.

If the car "pulls" in one direction only now, then you have an alignment issue. If it pulls both ways on specific roads, then it is no big deal, or your wheel bearings could be messed up.