Kevins TrackBar setup VS TNT setup - Bumpsteer...

which Trackbar setup has more bump steer?
The TNT setup looks like it has strange angles... but I like the Bracket better.

The Kevins (JKS) setup has better angles on the trackbar and the extra bend to lessen the bumpsteer...

6.5 inches of lift, I made a custom Drop bracket for my RE HD but I got a ton of bump steer.
any thoughts on which will solve the bumpsteer?

No bend will make the slightest difference to bump steer!
Bump steer is caused by having the drag link and the trackbar at different angles. Get those two parallel and you are well on the way to not having any bumpsteer.

The trackbar may have bends in it, but they are done to clear the diff and other components. A straight bar is stronger if made from the same material, it just needs proper clearance.

To figure out the angle make a straight line from mounting point to mounting point.

Gojeep hit the nail on the head...
It sounds like it's time to work on your steering. Your drag link angle is probably too steep compared to the track bar angle.

I have the TNT's full lift kit which includes the trackbar setup and I get some ugly bump steer issues and hate it. I am currently trying to figure out what steering/ trackbar system to use or how to fix the problem I have.

Gojeep said:

No bend will make the slightest difference to bump steer!
Bump steer is caused by having the drag link and the trackbar at different angles. Get those two parallel and you are well on the way to not having any bumpsteer.

Click to expand...

Thanks for your input... do you have either of them?

OTK

TNT said:

The trackbar may have bends in it, but they are done to clear the diff and other components. A straight bar is stronger if made from the same material, it just needs proper clearance.

To figure out the angle make a straight line from mounting point to mounting point.

Gojeep hit the nail on the head...
It sounds like it's time to work on your steering. Your drag link angle is probably too steep compared to the track bar angle.

Click to expand...

ok... so you make the TNT ones... if you thought a bend doesn't change it you wouldn't put a bend in...
thats why I am considering the JKS...

The angle that the Track bar pivots will determine how much the axle moves to the passengers side when hitting a bump. if the pivot is linear than the effect minimal
if the pivot is diagonal the effect of the bump is maximized.
As the jeep gets taller the angle of the pivot gets larger, therefore creating more bumpsteer.

I like your TNT setup better than JKS for strength, but I am considering if it is worth the sacrifice of road stability.

For what it's worth, I have a modified Kevin's TB with OTK Steering links. My angles are near equal and have no bumpsteer at 6.5" of lift. Fix your angles and you will have stability with either trackbar.

Winks00XJ said:

I have the TNT's full lift kit which includes the trackbar setup and I get some ugly bump steer issues and hate it. I am currently trying to figure out what steering/ trackbar system to use or how to fix the problem I have.

Click to expand...

what size lift?
what steering setup do you have now?

muduck18 said:

ok... so you make the TNT ones... if you thought a bend doesn't change it you wouldn't put a bend in...
thats why I am considering the JKS...

The angle that the Track bar pivots will determine how much the axle moves to the passengers side when hitting a bump. if the pivot is linear than the effect minimal
if the pivot is diagonal the effect of the bump is maximized.
As the jeep gets taller the angle of the pivot gets larger, therefore creating more bumpsteer.

I like your TNT setup better than JKS for strength, but I am considering if it is worth the sacrifice of road stability.

Click to expand...

I'm not affiliated with T&T Customs Inc. I'm the original TNT here on the forum from way back in 2001 or earlier. They lost my original join date when they did a forum upgrade.

The angle of any trackbar or control arm is a straight line from one pivot point to the other. Any bends in between the pivot points do not affect that angle, they are just there for clearance reasons.

Yes the angle that the trackbar pivots will determine how much the axle moves to the passengers side when hitting a bump but if the drag link is at the same angle as the trackbar is at bumpsteer is minimal if there is any at all.

A lower angle will trackbar angle will help eliminate side to side movement of the axle, but if the draglink angle isn't the same you will have bumpsteer.

Ideally you want a low angle trackbar with as few bends in it as possible(for strength reasons) and a drag link angle that matches the trackbar angle.

muduck18,

I recently found myself in the same position you are in currently.

I was trying to decide on the TNT Customs vs. the Kevin's Trac bar. In the long run, I chose Kevin's. Just ordered it this morning in fact.

After reading several threads, talking to a few enthusiasts, and going over a few of my own problems... I came to the conclusion of Kevin's.

I'm in the process of trying to eliminate the bumpsteer than occurs with my rusty's "adjustable." I changed my lift around a bit and needed a new trac bar anyways. Not to mention the new steering setup, I'm trying to get my angles right as well.

I'm also trying to rid myself of as much of the Rusty's parts that I have as well. After reading about a numerous number of failures when it comes to rusty's parts, I wanted to eliminate the possibility on my rig.

When mine gets here, I'll update with some pics and info if you'd like. But my vote is going to go to Kevin's at this point.

Scott

TNT said:

I'm not affiliated with T&T Customs Inc. I'm the original TNT here on the forum from way back in 2001 or earlier. They lost my original join date when they did a forum upgrade.

The angle of any trackbar or control arm is a straight line from one pivot point to the other. Any bends in between the pivot points do not affect that angle, they are just there for clearance reasons.

Yes the angle that the trackbar pivots will determine how much the axle moves to the passengers side when hitting a bump but if the drag link is at the same angle as the trackbar is at bumpsteer is minimal if there is any at all.

A lower angle will trackbar angle will help eliminate side to side movement of the axle, but if the draglink angle isn't the same you will have bumpsteer.

Ideally you want a low angle trackbar with as few bends in it as possible(for strength reasons) and a drag link angle that matches the trackbar angle.

Click to expand...

My Apologies, I had you confused with T&T customs...

I am going to graph it out and see if it will make a difference.
my preliminary sketches indicate that it will change it.

I understand that the angle is the most important part, but I am hesitant to agree about the bends in between.
By changing the quadrant of the pivot point you change the motion of the circumference.
the bend in the bar is not what makes the difference it is the angle of the bar as it attaches to the frame, this pivot point will dictate the lateral motion of the axle..
The difference will be very little but when you are dealing with a fraction of an inch in steering and alignment it makes a world of difference.


That is the theory that I am going on right now.
I will graph or cad this and see if i should just shut up and buy one of them.

Thanks anyway.
--

Don't over think it.

Here's a simple way to think about the bends. Make a 6" long straight coat hanger and one thst has a couple of bends in it but is 6" long also.

Hold one end stationary(one pivot end like the frame end. Now pivot it 90 degrees. Do the same with the bent one and you will find they act exactlly the same. The bends don't effect the circumference of travel made by either.

Now pull on each of them and see which one is stronger.

To make the bent one as strong you need to increase it's size.

Since the track bar and drag link are different lengths they need to be at the same angle at your ride hieght on level ground. They will not always stay at the same angle do to the different lengths but this is only noticeable at the extreme limits of suspension travel.

Like I stated before, ideally you want a low angle trackbar with as few bends in it as possible(for strength reasons) and a drag link angle that matches the trackbar angle.

You also want to try and keep the overall length of each as close as possible.

You want a tie rod that goes from knuckle to knuckle to eliminate toe in change as the suspenion cycles also. Run your drag link to the tie rod since this will make it slightly shorter and run as long of a trackbar as possible. This will eliminate toe in change and limit the side to side motion of the axle along with bumpsteer.

Bends mean absolutley nothing,only pivot points,END of STORY!!

RCP Phx said:

Bends mean absolutley nothing,only pivot points,END of STORY!!

Click to expand...

Thats right. I ordered a TnT tracbar today and was clearly told that with a droped track bar braket a drop pitman arm will stop bump steer. From my personal past experiance the more you drive with bumpsteer the more you get used to it and you subconsiously turn the steering wheel to compensate for it. Some folks can get used to it and some cant. I'll just hope I can get used to it again when my drop braket is installed and if not I will remedy the condition with a drop pitman arm or better yet over the knuckle conversion on the passenger side.

so, I put down my crack pipe today...
And got out my elementary geometry book...


I kept thinking that the pivot angle made a difference. because I kept drawing a mental line straight from center of the pivot instead of straight between the two points.
:wstupid:
I also realized why i have bumpsteer. because of the same elementary stuff. when i built my custom track bar mount I moved the mount point 2 inches closer to the center of the jeep... (to compensate for a trackbar not long enough to adjust for my lift size.)
when i did that I made the trackbar and the steering mount at a different point.

So... people like the TNT track bar huh?
Any clearance issues? :dunce:

thanks.

muduck18 said:

what size lift?
what steering setup do you have now?

Click to expand...

I have the 5.5 lift but sits around 7 inches of lift. I am using the Currie steering system along with the TNT Customs trackbar. This combo causes some severe bumpsteer. I have tried the drop pitman arm they provide but it didnt help at all. I am not sure what needs to happen to make it better but hope to get some time soon to work out what needs to happen.

muduck18 said:

so, I put down my crack pipe today...
And got out my elementary geometry book...


I kept thinking that the pivot angle made a difference. because I kept drawing a mental line straight from center of the pivot instead of straight between the two points.
:wstupid:
I also realized why i have bumpsteer. because of the same elementary stuff. when i built my custom track bar mount I moved the mount point 2 inches closer to the center of the jeep... (to compensate for a trackbar not long enough to adjust for my lift size.)
when i did that I made the trackbar and the steering mount at a different point.

So... people like the TNT track bar huh?
Any clearance issues? :dunce:

thanks.

Click to expand...

If it isnt a hassle, I would take a picture of your front steering as is and post it into this thread, before you throw more money at it. Never hurts to have some other eyes on it and a picture is worth 1000 words, some times even more. Chances are that you are on the right trail, but if it was me I would feel better with an additional opinion.

As above, post a picture but what also helps is have a string line running from centre of ball joint, ( not the point where it bolts to the frame bracket ) to centre of the bolt at the axle end of the trackbar. Or centre of both bolts if you do not have a ball joint any more.
If you have a angle finder, just place it under the drag link and then under the string line and compare the angles. They should be exactly the same. Simple as that. If not, you either alter the drag link angle by doing a OTK to raise the axle end ( if that gets it to the same angle ) or fitting a different drop pitman arm. Or alter either end of the trackbar height to make it the same as the drag link.
It is always better to raise the axle end if you can as it raises the roll centre which give you less body roll in off camber situations and on the street during cornering. Big drops are bad also on a pitman arm as it increases the leverage on the box and the frame mount. I would not fit anything more than a ZJ one which lowers it 3/4".

Thanks Guys,
I will try to snap a picture tonight and post it.
just as a pre-cursor...
I have the RE 4.5 superflex lift. that came with a RE Trackbar...
I later upgraded to JKS UCA's for adjustability.
and I also added a spacer on the springs to make the front match the back in height. (front measures 6.5in, rear measures 6.25in but it still looks taller in the back for some reason.)
anyway.
when I added the spacer I welded a drop bracket on to the top of the TracBar (using the same type of setup as the JKS weld-on) but i moved it in more to compensate for the now short TrackBar.

I have been planning on replacing the trackbar ever since with a full bracket and everything so I am not spending money that I was not already planning on spending. (45k Mi + is a killer to that RE track bar anyway)

I also have the Drop pitman (it measured 3/4" lower than the stock)
when I added the Drop pitman it almost eliminated the BumpSteer but its still not back to where it was before lift... Maybe I am dreaming...
My wife drives it on occasion so I am trying to make it as safe as possible for her.