Bump Steer or something else??
12-22-2015, 07:01 PM
#16
Seasoned Member
It is most likely a combination of things, but two (or more) separate problems.
The drag link vs. track bar geometry is the biggest culprit in bump steer. And it's really easy to understand. Here are a couple of photos which should clear things up. Both of these were pulled off of a Google search a long time ago, don't remember who authored them.
Basically if the two pieces move in different arcs, the axle gets pulled or pushed side to side with respect to the steering...so you steer going over a bump. The important part is parallel arcs, and both of the images show OK setups.
A quick way to check for that is to see if your track bar and drag link are parallel when sitting on the ground at ride height. If they are not parallel, you probably have different arcs of movement. You can still have issues if they are parallel, but that's another topic we can tackle after you do the quick check.
The drag link vs. track bar geometry is the biggest culprit in bump steer. And it's really easy to understand. Here are a couple of photos which should clear things up. Both of these were pulled off of a Google search a long time ago, don't remember who authored them.
Basically if the two pieces move in different arcs, the axle gets pulled or pushed side to side with respect to the steering...so you steer going over a bump. The important part is parallel arcs, and both of the images show OK setups.
A quick way to check for that is to see if your track bar and drag link are parallel when sitting on the ground at ride height. If they are not parallel, you probably have different arcs of movement. You can still have issues if they are parallel, but that's another topic we can tackle after you do the quick check.
Hey thanks for the advice, I figured all of what you said might be the case, so I did research on what I should check and took it to my mechanic to check out. The geometry stuff is getting over my head. I looked through the other parts and can't find anything wrong loose or worn.
I figured that all of this is a combination of things.
I figured that all of this is a combination of things.
12-22-2015, 07:06 PM
#17
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It is most likely a combination of things, but two (or more) separate problems. The drag link vs. track bar geometry is the biggest culprit in bump steer. And it's really easy to understand. Here are a couple of photos which should clear things up. Both of these were pulled off of a Google search a long time ago, don't remember who authored them. Basically if the two pieces move in different arcs, the axle gets pulled or pushed side to side with respect to the steering...so you steer going over a bump. The important part is parallel arcs, and both of the images show OK setups. A quick way to check for that is to see if your track bar and drag link are parallel when sitting on the ground at ride height. If they are not parallel, you probably have different arcs of movement. You can still have issues if they are parallel, but that's another topic we can tackle after you do the quick check.
If that is not the culprit, what do you think it could be?
12-24-2015, 10:24 AM
#18
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It is most likely a combination of things, but two (or more) separate problems. The drag link vs. track bar geometry is the biggest culprit in bump steer. And it's really easy to understand. Here are a couple of photos which should clear things up. Both of these were pulled off of a Google search a long time ago, don't remember who authored them. Basically if the two pieces move in different arcs, the axle gets pulled or pushed side to side with respect to the steering...so you steer going over a bump. The important part is parallel arcs, and both of the images show OK setups. A quick way to check for that is to see if your track bar and drag link are parallel when sitting on the ground at ride height. If they are not parallel, you probably have different arcs of movement. You can still have issues if they are parallel, but that's another topic we can tackle after you do the quick check.
12-26-2015, 12:22 PM
#20
Seasoned Member
Yeah, coils have nothing to do with bump steer. Photos of your setup would be handy.
In response to your previous post:
Yes, measuring the distance between your track bar and drag link in two places (near each end) will be a good start. If it is not that, there are other things it could be, which we will step through and talk about once you have done this first check and posted a photo of your entire steering linkage.
In response to your previous post:
Yes, measuring the distance between your track bar and drag link in two places (near each end) will be a good start. If it is not that, there are other things it could be, which we will step through and talk about once you have done this first check and posted a photo of your entire steering linkage.
12-26-2015, 03:50 PM
#21
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Yeah, coils have nothing to do with bump steer. Photos of your setup would be handy. In response to your previous post: Yes, measuring the distance between your track bar and drag link in two places (near each end) will be a good start. If it is not that, there are other things it could be, which we will step through and talk about once you have done this first check and posted a photo of your entire steering linkage.
01-03-2016, 08:34 PM
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Yeah, coils have nothing to do with bump steer. Photos of your setup would be handy. In response to your previous post: Yes, measuring the distance between your track bar and drag link in two places (near each end) will be a good start. If it is not that, there are other things it could be, which we will step through and talk about once you have done this first check and posted a photo of your entire steering linkage.
01-03-2016, 08:50 PM
#23
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And my measurements are:
Passenger side: 13.5 to my drag link and 15 to my track bar
Driver side: 19.75 to my drag link and 20.5 to my track bar. Will half an inch make that big of a difference?
Passenger side: 13.5 to my drag link and 15 to my track bar
Driver side: 19.75 to my drag link and 20.5 to my track bar. Will half an inch make that big of a difference?
01-04-2016, 10:24 PM
#25
Seasoned Member
Hey man, welcome back and Happy New Year.
Where did you measure on the passenger side? At the same distance out from the wheel (track bar mount, I assume)?
The stock track bar is about 37" long, so 3/4" off is about 1 degree off parallel. Not bad.
How much are you lifted?
Where did you measure on the passenger side? At the same distance out from the wheel (track bar mount, I assume)?
The stock track bar is about 37" long, so 3/4" off is about 1 degree off parallel. Not bad.
How much are you lifted?
01-04-2016, 10:27 PM
#26
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Hey man, welcome back and Happy New Year. Where did you measure on the passenger side? At the same distance out from the wheel (track bar mount, I assume)? The stock track bar is about 37" long, so 3/4" off is about 1 degree off parallel. Not bad. From your photo, it looks like your lift *might* be the problem. Your track bar and drag link are at a steep enough angle away from level that they probably sweep different paths. Since the track bar is shorter, it will tend to shift the axle side to side more than the drag link pushes or pulls the steering. Since the distances things move are different, that difference is "soaked up" as bump steer. How much are you lifted?
Yes, I measured form the track bar mount on the passenger side. I'm only lifted 3 inches. I went through and tightened everything up tonight and it helped, but still get it every once in a while.
01-07-2016, 06:57 PM
#28
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01-09-2016, 05:16 PM
#29
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It's getting hard to help out, as I can't tell the severity of symptoms. All XJs will bump steer at some times.
If symptoms still persist we can continue to try and work it out.
If symptoms still persist we can continue to try and work it out.
01-14-2016, 09:51 PM
#30
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Other than that, should I just replace my track bar and tie rod at a shop and trust they will dis the issue?