Longer pitman arm

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04-28-2014, 03:56 PM
Timmy

Longer pitman arm

Okay, sorry guys, newbie JK owner so I have lots of questions about things I can change ;-)

Like many other JKU owners, I'd love it if the JKU could turn tighter. I see lots of people post questions on this, and the answer that comes back is almost always "don't even try, or you'll get tire rub on something." To which, I see lots of reports of increasing the steering stop bolt to reduce how much the tire can turn to stop the tire rubbing.

Well... In my case, I actually think I could get a tighter turn without tire rub. I'm running 35" tires on XD Bully rims which kick the tires out considerably with a 4" lift, and at full left or right wheel lock, there is NOTHING even remotely close to rubbing. I can't say for sure how much this remains true if the suspension is compressed, so I have to assume that a compressed suspension would inherently bring some parts of the frame closer to the tire. Regardless... While everyone was worried about tire rub, I actually went out and removed my steering stop bolts all together and then tested to see if it A) turned any tighter and B) rubbed (I put the bolts back in after the test.) Well, the Jeep _maybe_ turned tighter, but is so minimal that you'd be hard pressed to know if it did, which makes sense given that the bolts look like they've hardly every made contact with the metal of the frame. I probably should have done a formal test of before/after with the stop bolts with marks on the ground to compare, but I just went with the butt-o-meter on this one as a very quick test.

So this got me thinking more, what in the world is preventing the wheels from turning even further? I turned hard left and right and looked under the Jeep, and to my best uneducated eye, it appears that the wheels are at full left/right due to the length of the pitman arm. If the arm was just a hair longer (and of course, the diverter arm then lengthened as needed) then I might be able to get just a few degrees more of turn on the wheels to the point where a shorter steering stop bolt might actually hit the frame, thereby allowing me to adjust until tire rub.

So, long story short, does anyone know if you can put a longer pitman arm on in addition to an adjustable diverter arm to try and gain some extra degrees on the turning? Is there some other way to decrease turning radius? (to me it seems like the pitman arm is the limiting factor here given that it is at it's full left/right position and can't extend either direction any further.) How far can you safely divert the wheels before the drivetrain starts to bind at the wheels due to the tight angle?
04-28-2014, 05:02 PM
UselessPickles

http://cdn.carthrottle.com/wp-conten...t_car_MEME.jpg

:)

Sorry, that's the most useful thing I have to contribute here.
04-28-2014, 06:01 PM
JeepLab

Quote:

Originally Posted by Timmy

Okay, sorry guys, newbie JK owner so I have lots of questions about things I can change ;-)

Like many other JKU owners, I'd love it if the JKU could turn tighter. I see lots of people post questions on this, and the answer that comes back is almost always "don't even try, or you'll get tire rub on something." To which, I see lots of reports of increasing the steering stop bolt to reduce how much the tire can turn to stop the tire rubbing.

Well... In my case, I actually think I could get a tighter turn without tire rub. I'm running 35" tires on XD Bully rims which kick the tires out considerably with a 4" lift, and at full left or right wheel lock, there is NOTHING even remotely close to rubbing. I can't say for sure how much this remains true if the suspension is compressed, so I have to assume that a compressed suspension would inherently bring some parts of the frame closer to the tire. Regardless... While everyone was worried about tire rub, I actually went out and removed my steering stop bolts all together and then tested to see if it A) turned any tighter and B) rubbed (I put the bolts back in after the test.) Well, the Jeep _maybe_ turned tighter, but is so minimal that you'd be hard pressed to know if it did, which makes sense given that the bolts look like they've hardly every made contact with the metal of the frame. I probably should have done a formal test of before/after with the stop bolts with marks on the ground to compare, but I just went with the butt-o-meter on this one as a very quick test.

So this got me thinking more, what in the world is preventing the wheels from turning even further? I turned hard left and right and looked under the Jeep, and to my best uneducated eye, it appears that the wheels are at full left/right due to the length of the pitman arm. If the arm was just a hair longer (and of course, the diverter arm then lengthened as needed) then I might be able to get just a few degrees more of turn on the wheels to the point where a shorter steering stop bolt might actually hit the frame, thereby allowing me to adjust until tire rub.

So, long story short, does anyone know if you can put a longer pitman arm on in addition to an adjustable diverter arm to try and gain some extra degrees on the turning? Is there some other way to decrease turning radius? (to me it seems like the pitman arm is the limiting factor here given that it is at it's full left/right position and can't extend either direction any further.) How far can you safely divert the wheels before the drivetrain starts to bind at the wheels due to the tight angle?

WHOA. I dont know about a longer pitman arm. What I will say, is that with a 4 inch lift, your center of gravity is higher, and sharp turning makes the truck body roll. Which if you go too far, will become a real roll. Im not sure you will be turning at higher speeds, but the same thing applys offroad. When you are on a rock turning, the same premise is true.

The opposite side of the coin is that your pushing the wheels out farther making the trucks base wider in theory.

I say leave it as it is. I dont think a shorter turning radius is worth changing the geometry of the pittman arm. once you play with the suspension's geometrics, other problems can a rise.
04-28-2014, 06:36 PM
Timmy

Quote:

Originally Posted by JeepLab

WHOA. I dont know about a longer pitman arm. What I will say, is that with a 4 inch lift, your center of gravity is higher, and sharp turning makes the truck body roll. Which if you go too far, will become a real roll. Im not sure you will be turning at higher speeds, but the same thing applys offroad. When you are on a rock turning, the same premise is true.

The opposite side of the coin is that your pushing the wheels out farther making the trucks base wider in theory.

I say leave it as it is. I dont think a shorter turning radius is worth changing the geometry of the pittman arm. once you play with the suspension's geometrics, other problems can a rise.

Well I can tell you that with the wider wheel base, I'm pretty amazed at how stable the thing is. I've taken some corners pretty fast and it is pretty rock solid. If there is a bump in the corner that is the bigger issue more so than the g-force/rolling factor. Don't forget, for the tightest of turning radius, that would be just parking lot maneuvers, so we're talking less then 5 mph here.
04-28-2014, 06:38 PM
Timmy

Yes, yes!!! That's exactly what I'm looking for, or maybe I should just go with 4 wheel steering? (grin.) I just read an article that 4 wheel steering is on the come back now that they have much more precise machining, parts and computers/monitoring/programming.