Caster angle, shims, and shackles? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Caster angle, shims, and shackles?

Spartan Locker Promo Running now @ ROCKRIDGE 4WD plus FREEG2 Disc Brake Conversion Kit for Jeep Wrangler YJ TJ LJ ChTJ Wrangler 4" Rough Country Suspension Lift Kits in

Reply
Unread 03-10-2010, 05:38 PM   #1
I6CJ7
Registered User
1984 CJ7 
 
Join Date: Aug 2009
Location: Virginia
Posts: 938
Caster angle, shims, and shackles?

My CJ7 has what I believe to be a 2-1/2" lift with small lift shackles that give about another 1/2" to it. My question is what degree shims do I need for the front axle? The PO put shims on the rear axle but not on the front soooo the steering has NO return to center at ALL. Seriously when I take an exit ramp to get off the highway I just turn the wheel and it stays turned through the whole curve! And the shackles that are on it are very nice and beefy but I think they are 2.5" wide YJ shackles so they sit ****ed outward because of the gap on either side of the spring eye and bushings. To fix this can I just throw some bigwashers in there to close the gap?

I6CJ7 is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 06:24 PM   #2
mtbtweety
Member
 
mtbtweety's Avatar
1982 CJ8 
 
Join Date: Dec 2009
Location: Cumming, GA
Posts: 267
pictures of the shackles?
mtbtweety is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 06:43 PM   #3
COBRA5LADDICT
Registered User
 
Join Date: Oct 2004
Posts: 292
you need to find out what your caster angle is currently before you can correct it. either get an alignment or do it at home (search there are plenty of threads on this). factory spec is 3-7 degrees positive. depending on your tire size 5-6 gives you a good feel for the road and good return to center.
COBRA5LADDICT is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 06:47 PM   #4
Dborns
Registered User
1983 CJ7 
 
Join Date: Jan 2010
Location: Kansas City, MO
Posts: 1,600
I had a similar problem on my CJ. It had huge 8" long shackles on the front and back and they also must have been for a YJ. They were too wide for the spring eye and the PO put a few washers in each side and also somehow, even though they were over 1/4" thick steel, squeezed them down so that they were pinched onto it. It rode like crap. I ended up switching them out with stock shackles and just getting them off was a real pain because of how they were installed. I'm sure the wandering ride was mostly due to the huge shackles, but I can't imagine throwing a bunch of washers in there helped either.
Dborns is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 08:39 PM   #5
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 10,714
Quote:
Originally Posted by I6CJ7 View Post
My CJ7 has what I believe to be a 2-1/2" lift with small lift shackles that give about another 1/2" to it. My question is what degree shims do I need for the front axle? The PO put shims on the rear axle but not on the front soooo the steering has NO return to center at ALL. Seriously when I take an exit ramp to get off the highway I just turn the wheel and it stays turned through the whole curve! And the shackles that are on it are very nice and beefy but I think they are 2.5" wide YJ shackles so they sit ****ed outward because of the gap on either side of the spring eye and bushings. To fix this can I just throw some bigwashers in there to close the gap?
There is no question you need to close up that gap!
What's happening is, when you try to make a steering change is the axles are moving, but the frame/body is NOT until you get to the end of the 'Slop', then it's getting YANKED over...

Must make for some scary lane changes or steering corrections running at highway speed!
---------------------------------

Tall tires and 'Lift' shackles will kill the 'Caster' on your front end...
Take the lift shackles off (if you have them) and get some stock length shackles.
That will return your caster more towards 'Stock'...

All 'Lift' shackles do is screw up your Caster and make the jeep flop around when you try to make lane changes...
You will feel everything 'Shift' before the vehicle actually starts turning, and that's not safe...

For the tires,
Use ball stud Caster/camber shims or off set ball joints.







You *MAY* show the correct caster for your specific year of vehicle,
But the taller the tire you run, the more caster you will need to make the vehicle steering return to center.

The ones I show in the pictures are pretty severe, about 5 added degrees of caster, but that's what it took to get my 3" lifted jeep with 33" tires to center again...

4 or 5 degrees is all you can get with shims, after that, it's time to cut the 'C's off the ends of the axles and re-orient them for more caster, weld them back on...

You can try off set ball joints, but they are fairly expensive and don't always give you enough to correct your 'Issues'...

Lift shackles on either end are dangerous, screw up drive line angles and pinion angles, and on the front kill your caster angle.
Back is bad enough, but on the front, they are just down right DANGEROUS, so if you have them, toss them and put on some that are stock length.
JeepHammer is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 08:49 PM   #6
Dborns
Registered User
1983 CJ7 
 
Join Date: Jan 2010
Location: Kansas City, MO
Posts: 1,600
Hey JeepHammer,
As I stated in the post above, I had the same setup with huge shackles, that made my CJ wander. I removed them and put stock back on. It drives alot better, but the steering is still sloppy, and I can turn the wheel about 1/4 turn before the wheels start to turn. Is that a caster problem that shims would correct, or is that more of a steering box problem?
Dborns is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 09:43 PM   #7
jeepskate
Web Wheeler
1986 CJ7 
 
Join Date: Aug 2004
Posts: 4,700
Quote:
Originally Posted by Dborns View Post
Hey JeepHammer,
As I stated in the post above, I had the same setup with huge shackles, that made my CJ wander. I removed them and put stock back on. It drives alot better, but the steering is still sloppy, and I can turn the wheel about 1/4 turn before the wheels start to turn. Is that a caster problem that shims would correct, or is that more of a steering box problem?
Could be just about any one or combo of things in the steering system. Just like the OP can't 'shortcut' his answer, neither can you. You need a helper to turn your steering wheel back and forth while you look for the slop starting with the steering column on down and out. You could have a bad 'rag joint' on your steering shaft, loose steering box bracket, worn out steering box, bad tie-rod ends, ball joints, worn out spring bushings...a myriad of things.
__________________
'86 CJ-7 Laredo: 4.2,T-999,D300,D30/D44,'94 YJ tub, full cage, Shrockworks rockers, OYR corners, AC,cruise,restored seats,3 tops,2.5" Superlift,F-T shackle reversal, RS9000x's,35" Dunlop Mud Rovers.
'83 Scrambler: time & money pit under construction with parts from CJ's,YJ's,TJ's,FSJ's,GM,Ford,IH,Honda,Toyota and a whole lotta aftermarket & custom stuff.
http://www.jeepskate.net
jeepskate is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 09:49 PM   #8
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 10,714
Quote:
Originally Posted by Dborns View Post
Hey JeepHammer,
As I stated in the post above, I had the same setup with huge shackles, that made my CJ wander. I removed them and put stock back on. It drives alot better, but the steering is still sloppy, and I can turn the wheel about 1/4 turn before the wheels start to turn. Is that a caster problem that shims would correct, or is that more of a steering box problem?
Sounds like sloppy steering box or linkage.
I wouldn't drive something on the highway that had 1/4 turn steering slop!

Have someone turn the wheel back and forth while you watch the output shaft where the pitman arm connects.

Usually, you will see the shaft move Up/Down from the lower bearing being shot when you have that much play.
That is the expensive and hard to replace part, so check it FIRST.

If it doesn't, then you just need some SERIOUS time with a tie rod/ball stud separator and pipe wrench and replace the sloppy link ends, ball joints, ect.

Don't forget to check the linkage under the hood, between bottom of steering column and steering box.
The U Joint right at the end of the steering column where it attaches to the steering rod sometimes goes out,
They are available at the Jeep supply places.

The rag joint or universal joint at the steering box sometimes gives up and needs replaced.
Again, all that stuff is available from Jeep supply places.
-----------------------------

There are a few reasons the vehicle might 'Wonder' or not self center.
The biggest reason is lift springs, lift shackles, soggy bushings in the springs and large tires.

I make my own shackles out of 1/4" steel plate, but that wouldn't work for the OP since he has an offset between hangers and YJ springs (Wider)...

Caster is a BIG thing when it comes to self centering,

But stuff like wheel spacing can cause some real problems.
Screws up the 'Scrub Radius', and that can cause 'Wondering' around and climbing tire grooves in the pavement.
JeepHammer is offline   Reply With Quote Quick reply to this message
Unread 03-10-2010, 09:55 PM   #9
Dborns
Registered User
1983 CJ7 
 
Join Date: Jan 2010
Location: Kansas City, MO
Posts: 1,600
Great info, JeepHammer. Can't wait to dig into this!
Dborns is offline   Reply With Quote Quick reply to this message
Unread 03-13-2010, 08:24 PM   #10
shortgoroper
Registered User
1983 CJ7 
 
Join Date: Feb 2008
Location: Athens, PA
Posts: 205
What is the stock shackle length??? I just took off a pair of 5" (bolt hole to bolt hole) death shackles.
shortgoroper is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.