Help with front end geometry

John Cooper

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Little background first, my now Jeep used to belong to my BIL, I got it for a good deal knowing the CEL was on and the AC didn't work. I honestly don't know if he had the lift installed or not but wanted to get some opinions on the front end geometry. Here are some pictures of what it looks like. I know it has a dropped pitman arm.
KIMG0640.JPG
KIMG0639.JPG
KIMG0638.JPG
 
That looks like a drop pitman arm. Avoid those like the plague. Order a OEM type pitman arm. This will keep the trackbar and the drag link parallel the way it should be. While the trackbar and drag link are at opposing angles like they are now, your on road performance will be subpar, and especially offroad you will get a lot of bind very quick. The stock spring heights measure at 12" for the front and 8" for the rear (installed). If your springs are longer then that, then the length you measure minus the stock heights equals your lift height. Unless you have spacers on top of the springs which should be easy to identify. If you have more than 2 inches of lift you'll really want to get adjustable track bars.
 
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I meant to say it does have a 4" lift on it. I am honestly thinking of going to a 3 inch. Just not sure what direction I really want to go.
 
more pics of the rig?
that it in the avatar?
if so looks like what you j have up front is not gonna afford much reduction due to wheel size.
if it's holding 4" of lift, a 3.5" in the rear might level it out. really depends on what array of parts were placed to accommodate the 4" you have in place. SYE, DCshaft, adjustable CA's and TB's. and what would have the room to drop and still have full function or travel.

the relationship of the drag link and TB should be as close to similar/parallel as possible, and as close in length as possible. bends and dips don't count it's joint to joint straight lines ( or joint through joint lines). most times a drop pitman can give undesirable steering effects because it changes this as parallel as possible relationship.
 
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more pics of the rig?
that it in the avatar?
if so looks like what you j have up front is not gonna afford much reduction due to wheel size.
if it's holding 4" of lift, a 3.5" in the rear might level it out. really depends on what array of parts were placed to accommodate the 4" you have in place. SYE, DCshaft, adjustable CA's and TB's. and what would have the room to drop and still have full function or travel.

the relationship of the drag link and TB should be as close to similar/parallel as possible, and as close in length as possible. bends and dips don't count it's joint to joint straight lines ( or joint through joint lines). most times a drop pitman can give undesirable steering effects because it changes this as parallel as possible relationship.
Sorry for the long delay I am on call this weekend and can't get the phone to stop ringing.
Non adjustable lower control arms and stock uppers front and rear. Non adjustable Trac bars front and rear.
It still sits at 4" of lift.
I got to do some decision making on this thing.
Thanks for anymore help/advise!!!
 
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Dropped pitman arm needs to be thrown away and replaced with a stock one. As of now your steering wheel moves back and forth over bumps (bumpsteer), a stock pitman arm will take that away and be the correct geometry.
 
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Little background first, my now Jeep used to belong to my BIL, I got it for a good deal knowing the CEL was on and the AC didn't work. I honestly don't know if he had the lift installed or not but wanted to get some opinions on the front end geometry. Here are some pictures of what it looks like. I know it has a dropped pitman arm.

1st, good on y'all for being able to take a CEL A/C deprived from you "brother in law" assuming BIL? PO from mine was a good guy...I still have some choice words for him when fixing things, ha. I'd be a little worried that could cause some issues at Christmas, ha.

I've got a 3.5" with some sag in the back. Working through lots of issues (sounds kind of similar). And I've been reading a ton here....and others would probably have more detail. Here's what I see which is similar:

I had a Drop Pitman Arm and just went to a Mopar factory one:
Before:
IMG_5181.jpg

I took it off and also I followed the ZJ Tie Rod upgrade thread....and went ahead and got a brand new Drag Link, 2 Tie Rod Ends, and 2 new sleeves from Moog on Amazon. Painted them and put it all on. The drive is very, very different.
After:
New Steering Linkage Jeep TJ.jpg
I had tires off and set the toe in to 1/16th of an inch using the method with aluminum pipe from Home Depot that I found on this chat room.

The relationship of the Drag Link and Track Bar are not correct with a drop arm, the "Working Plane" that is drawn from mounting point to mounting point cross paths like this picture I drew of mine before:
No Parallel Drag Link.jpg

I've read and now agree that 4" lift or less there's no need for this drop pitman arm. Someone that works on 50 rigs a year would know better when that number drives it (and I'm sure there's a way to make one work, going to factory seems from what I've read and now my personal experience to correct any issues).

Here's a pic after going back to factory:
Parallel Pitman Factory Steering 05 TJ - Copy.jpg

I've seen the term "Parallel" to describe the plains.....someone jumped my chili saying it's not, whatever, it's pretty close and I haven't plotted it, whatever the description, you see the relationship in the pictures.

I just drove about 40 minutes on major highways and 40 back to a baseball fields here in Texas, and I can drive 75 with a light hand on the wheel. That includes some bump areas that I had to hold on tight, because I'd be at 65mph and the wheel would jerk. I put it off WAY too long, WAY too long.

Other than that, I changed out control arms to adjustable and front track bar adjustable. If you make those changes, I'm not sure if there's a huge need to go down from 4". I'm not sure I'm following the "why", you don't like the look, or other issue?

I'd spend my time getting the CEL to go away, and steering buttoned up, then make a list....and ask "why" on each one to yourself, if that's what you want. Unless you're looking for projects, there may be less that you need to do, no need to change things just for the sake of it.
 
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1st, good on y'all for being able to take a CEL A/C deprived from you "brother in law" assuming BIL? PO from mine was a good guy...I still have some choice words for him when fixing things, ha. I'd be a little worried that could cause some issues at Christmas, ha.

I've got a 3.5" with some sag in the back. Working through lots of issues (sounds kind of similar). And I've been reading a ton here....and others would probably have more detail. Here's what I see which is similar:

I had a Drop Pitman Arm and just went to a Mopar factory one:
Before:
View attachment 184069

I took it off and also I followed the ZJ Tie Rod upgrade thread....and went ahead and got a brand new Drag Link, 2 Tie Rod Ends, and 2 new sleeves from Moog on Amazon. Painted them and put it all on. The drive is very, very different.
After:
View attachment 184070
I had tires off and set the toe in to 1/16th of an inch using the method with aluminum pipe from Home Depot that I found on this chat room.

The relationship of the Drag Link and Track Bar are not correct with a drop arm, the "Working Plane" that is drawn from mounting point to mounting point cross paths like this picture I drew of mine before:
View attachment 184076

I've read and now agree that 4" lift or less there's no need for this drop pitman arm. Someone that works on 50 rigs a year would know better when that number drives it (and I'm sure there's a way to make one work, going to factory seems from what I've read and now my personal experience to correct any issues).

Here's a pic after going back to factory:
View attachment 184077

I've seen the term "Parallel" to describe the plains.....someone jumped my chili saying it's not, whatever, it's pretty close and I haven't plotted it, whatever the description, you see the relationship in the pictures.

I just drove about 40 minutes on major highways and 40 back to a baseball fields here in Texas, and I can drive 75 with a light hand on the wheel. That includes some bump areas that I had to hold on tight, because I'd be at 65mph and the wheel would jerk. I put it off WAY too long, WAY too long.

Other than that, I changed out control arms to adjustable and front track bar adjustable. If you make those changes, I'm not sure if there's a huge need to go down from 4". I'm not sure I'm following the "why", you don't like the look, or other issue?

I'd spend my time getting the CEL to go away, and steering buttoned up, then make a list....and ask "why" on each one to yourself, if that's what you want. Unless you're looking for projects, there may be less that you need to do, no need to change things just for the sake of it.
Thanks for the reply, I have taken care of the CEL and the AC needed charged lol. Yes BIL is brother in law, it's not that I don't like the 4" lift, I am just looking at options and lift opinions.
What's odd is my Jeep will cruise at 60-70 with no vibes at all. What I do have a problem with is the steering can be real touchy and twitchy.
 
Thanks for the reply, I have taken care of the CEL and the AC needed charged lol. Yes BIL is brother in law, it's not that I don't like the 4" lift, I am just looking at options and lift opinions.
What's odd is my Jeep will cruise at 60-70 with no vibes at all. What I do have a problem with is the steering can be real touchy and twitchy.
That's what I had, touchy twitchy is a good way to put it. I had bad habits, owned a '78 CJ in college that I just got used to driving that way. It's not expensive to fix the steering and button it up, or not overly. Pitman arm took the rental tool, getting it super torqued, and a mini sledge 5 or 6 good blows to the Pitman where it seats, to get it off, well worth the effort.
 
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A new pitman arm is easy, everything else looks fine. If you are planning to wheel in the rocks a ZJ steering upgrade is nice. Unless I missed it the tire size you want to run is really important to the discussion.
 
A new pitman arm is easy, everything else looks fine. If you are planning to wheel in the rocks a ZJ steering upgrade is nice. Unless I missed it the tire size you want to run is really important to the discussion.
Will be picking up a pitman arm next week. I will probably continue to run 33 12.50 15. Probably won't be in the rocks that much. Getting ready to order diff parts for a regear to 4.56 also.
 
Plenty of great information here about how to fit 33" tires. I hear about 3" suspension lift and a body lift all the time but there are definitely people with much more experience than I have that can point you in the right direction. I think you do need closer to 4" total to clear 33" tires.
 
Plenty of great information here about how to fit 33" tires. I hear about 3" suspension lift and a body lift all the time but there are definitely people with much more experience than I have that can point you in the right direction. I think you do need closer to 4" total to clear 33" tires.
I have a (more than likely) rough country 4" lift on it now. I understand about needing 4" to run 33" tires. I am just wondering and what ifing about piecing together something like a combo lift with good parts.
 
I have a (more than likely) rough country 4" lift on it now. I understand about needing 4" to run 33" tires. I am just wondering and what ifing about piecing together something like a combo lift with good parts.
If it drives nicely now and all that's wrong is the steering is a bit twitchy I'd bet you can fix that easily. Get that pitman arm replaced and make sure everything is tight. Set your toe just right and report back.
 
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