Jk Caster problems....
Thread Starter
JK Newbie
Joined: Jan 2009
Posts: 21
Likes: 0
From: Pueblo,Colorado
Jk Caster problems....
I just installed a Teraflex 4" long arm kit with 37" BFG Km2's and I'm having trouble with bump steer and a mild case of death wobble. I have a flip kit coming in the mail along with the track bar brace. Teraflex says i need to run my caster at 3.5 and other guys are telling me 6-7. Just curious as to what everyone else was running
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
From the FAQ's that you haven't found yet...
And the DIY Alignment write-up...
http://project-jk.com/jeep-jk-write-...-end-alignment
I have seen several posts from the TF rep saying he runs low caster. No clue how he does it, since pretty much everyone else is running more than stock.
Q: What is Caster? How much do I need?
A: Caster is the angle upon which your front axle sits at in order to help keep your Jeep driving straight. Positive caster, which is what you want, will cause your axle to sit in a way that your pinion shaft will be dipping ever so slightly towards the ground. Too little or even negative caster angle can cause your Jeep to wander and feel 'flighty' or 'darty' as I've heard some people call it. From the factory, your JK will have +4.2° of caster and if you lift it and install larger tires, you will need to increase this amount to help compensate for the modifications. At 3"-4" of lift, I have found that +6°~8° of caster will do wonders to help improve the handling of your Jeep JK Wrangler.
A: Caster is the angle upon which your front axle sits at in order to help keep your Jeep driving straight. Positive caster, which is what you want, will cause your axle to sit in a way that your pinion shaft will be dipping ever so slightly towards the ground. Too little or even negative caster angle can cause your Jeep to wander and feel 'flighty' or 'darty' as I've heard some people call it. From the factory, your JK will have +4.2° of caster and if you lift it and install larger tires, you will need to increase this amount to help compensate for the modifications. At 3"-4" of lift, I have found that +6°~8° of caster will do wonders to help improve the handling of your Jeep JK Wrangler.
And the DIY Alignment write-up...
http://project-jk.com/jeep-jk-write-...-end-alignment
I have seen several posts from the TF rep saying he runs low caster. No clue how he does it, since pretty much everyone else is running more than stock.
JK Freak
Joined: Nov 2007
Posts: 575
Likes: 0
From: Everett, WA
I'm running 5.5 degrees on the ome hd lift. Stock settings equaled a terrible ride and death wobble. Ever since I bumped it up it drives great. Since yours is even higher I would think 6-7 would be appropiate. I'm not trying to call teraflex a liar but it seems odd almost everyone runs higher castor except for him. Seems like a marketing ploy or something, "4 inches of lift while retaining factory ride" etc blah blah
JK Freak
Joined: Mar 2008
Posts: 500
Likes: 1
From: Scottsdale, AZ
Re: Jk Caster problems....
Sometimes there is really bad advice given here by people that don't know what they are talking about... And to call out a good reputable vendor at the same time? Lame...
You want to run as much caster as you can... Within reason. The reason TF says +/- 3.5 is because you have an aftermarket DS with that amount of lift (I hope). With an aftermarket double carden DS you can't run as much caster because you will get DS vibes. That limit is unique to each rig but is often in the range of 3.5-4.5... Now with the zseppa joint in the stock DS you can run upwards of 6-7 without DS vibes. I continue to increase mine until I get a vibe then back it off.
Sent from my DROIDX using Tapatalk
You want to run as much caster as you can... Within reason. The reason TF says +/- 3.5 is because you have an aftermarket DS with that amount of lift (I hope). With an aftermarket double carden DS you can't run as much caster because you will get DS vibes. That limit is unique to each rig but is often in the range of 3.5-4.5... Now with the zseppa joint in the stock DS you can run upwards of 6-7 without DS vibes. I continue to increase mine until I get a vibe then back it off.
Sent from my DROIDX using Tapatalk
Last edited by RubiJK; Jul 30, 2010 at 02:57 PM.
JK Super Freak
Joined: Jul 2008
Posts: 1,934
Likes: 0
From: Middle of no where
More caster does not mean better ride all the time. I have had my 3 inch t flex lift castor from 3-7, currently running 4.5, rides perfectly. Now remember, a lot of numbers people throw out are the angle measurement from the angle finder. This does NOT measure castor. When I took the angle meansurement, my 4.5 equaled 7 degrees on the angle finder.
Last edited by Ryanc; Jul 30, 2010 at 02:52 PM.
JK Freak
Joined: Mar 2008
Posts: 500
Likes: 1
From: Scottsdale, AZ
More caster does not mean better ride all the time. I have had my 3 inch t flex lift castor from 3-7, currently running 4.5, rides perfectly. Now remember, a lot of numbers people throw out are the angle measurement from the angle finder. This does NOT measure castor. When I took the angle meansurement, my 4.5 equaled 7 degrees on the angle finder.
Trending Topics
Sponsoring Manufacturer
Joined: Apr 2007
Posts: 6,824
Likes: 3
From: Utah
I have a 4" LA kit in my JK with the flip kit running 3.4 degress of caster. Typically a TeraFlex kit will sit taller than other brands. The taller a JK is lifted the less caster is needed. Install the flip kit, run the caster at 3.5 and drive it.
Marketing ploy?
This kit rides better than factory.
Marketing ploy?
This kit rides better than factory.
Last edited by TeraFlex; Jul 30, 2010 at 03:12 PM.
Thread Starter
JK Newbie
Joined: Jan 2009
Posts: 21
Likes: 0
From: Pueblo,Colorado
Jk Caster problems....
I've been anywhere from 3.5 to 8. I think I've taken my links off 20 times... It ran the best when I had the caster at 6.5 but there was still slot of bump steer in my opinion. I tried to fine tune it a little and it just seemed to get worse.
My frame brace and flip kit just showed up, so I guess I'll see if this helps much.
My frame brace and flip kit just showed up, so I guess I'll see if this helps much.
JK Enthusiast
Joined: Feb 2010
Posts: 422
Likes: 0
From: Plover, WI & Benson, AZ
Sometimes there is really bad advice given here by people that don't know what they are talking about... And to call out a good reputable vendor at the same time? Lame...
You want to run as much caster as you can... Within reason. The reason TF says +/- 3.5 is because you have an aftermarket DS with that amount of lift (I hope). With an aftermarket double carden DS you can't run as much caster because you will get DS vibes. That limit is unique to each rig but is often in the range of 3.5-4.5... Now with the zseppa joint in the stock DS you can run upwards of 6-7 without DS vibes. I continue to increase mine until I get a vibe then back it off.
Sent from my DROIDX using Tapatalk
You want to run as much caster as you can... Within reason. The reason TF says +/- 3.5 is because you have an aftermarket DS with that amount of lift (I hope). With an aftermarket double carden DS you can't run as much caster because you will get DS vibes. That limit is unique to each rig but is often in the range of 3.5-4.5... Now with the zseppa joint in the stock DS you can run upwards of 6-7 without DS vibes. I continue to increase mine until I get a vibe then back it off.
Sent from my DROIDX using Tapatalk