Bump Steer

[Brady18]

I have been having an issue for a little while now. I replaced my stock front suspension with Rancho Quik Lifts. I did that the day after I bought my truck so I am not entirely sure what it felt like before I changed them out.

Anyways, whenever I go over a bump, especially washboard type bumps, my back end feels like it is going to swing so hard to the left (always to the left and never to the right) that I am about to start swerving all over the place. It is kind of scary at times. I am not sure if it has anything to do with the Rancho leveling kit but wanted ideas from everyone of what it could be and how to fix it. Thanks.

 

[6.7CumminsDrvr]

If you only changed the front suspension, it shouldn't affect the rear. I beleive what you are experiencing is a common symptom of trucks with rear coils and a track bar. When the suspension compresses, the axle will try to move laterally to the left. Conversely, as the suspension cycles up(unloads), it will want to move towards the right. This is a very simple explanation, maybe somebody with a more technical vocabulary will chime in.

EDIT: may have the direction wrong but basically the track bar causes the rear axle to move laterally. Hope this helps.

 

[Brady18]

Just seems kind of dangerous. Yesterday on my way to work it almost made me wreck. It wasn't even a huge bump and I was only going 50. Doesn't seem to make sense that something that we have to live with could be that dangerous.

 

[6.7CumminsDrvr]

Well, if you left the rear end alone you might want to have it checked out, what you just described does indeed not sound normal. I have 1" spacers in the rear of my truck so I know my rear axle is SLIGHTLY of centered but I havn't had the rear kick out to the point I felt it was gong to cause me to wreck.

I see you have 295/60/20's, how much pressure are you running in the rear? I know e-rated tires can affect ride/handling..........firmer side walls and more PSI (compared to stock tires).

 

[Brady18]

PSI in rear is at 40-45. Just left it at what they put in it when they installed the new wheels and tires.

 

[charonblk07]

It's a common symptom of dog-tracking where the front/rear wheels aren't perfectly aligned and the line of thrust is out ever so much. Most of my Rams have always kicked out to the left until I had a custom rebuild done on the axle mounts coupled with a set of adjustable arms and now it's perfectly straight every time. The factory control arms are fixed and don't give you any room to adjust on the rear so you're stuck with it unless you get a set of adjustable arms where you have 6 degrees of adjustment with them to get it perfect.

 

[Brady18]

Sorry if my question is a dumb one but those control arms you replaced are those for the rear? And if so, can you replace upper without replacing lower and vice versa? Or do I need to replace upper and lower of front and rear?