Header and Death Wobble

cherokee pilot

New Member
Location
Orem, Utah
I have 2 separate questions.

1. What is a good performance header for a 1998 4.0 XJ?

2. I have Death Wobble but when I put on new tires it goes away. This is a stock 1998 XJ
 
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xjtony

Well-Known Member
Location
Grantsville, Ut
Death wobble is almost always caused by multiple issues that combine to cause the issue. In my experience the main factors that contribute to DW are:
Caster- Running too little caster causes the axle to wander and can be a factor. For most rigs 5-7 degrees is good
Toe- If your toe is off the tires will fight each other
Tire balance- causes vibration that can combine with other factors
Loose steering joints- same thing
Incorrect angles in the steering/ track bar- Really common on lifted jeeps, but probably not the issue here if its stock.

With the tires on the ground have someone turn the steering wheel (both fast back and forth and from lock to lock) to see if you can see any play anywhere.
 

N-Smooth

Smooth Gang Founding Member
Location
UT
don't spend any money on a header. you won't get it back in noticeable hp/tq numbers

I always look at caster and tracbar first for DW. turning the wheel back and forth as you were advised above is a great start.
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
I have two manifolds for the 4.0. One is a replacement manifold that has the expansion sections, and the second one is a header that needs some welding which I can take care of.
 

XJEEPER

Well-Known Member
Location
Highland Springs
Unless you have performed extensive engine work (ported head, cam, stroker, etc.) then you wont see a return on investment on an aftermarket header (Banks makes a good unit). A quality replacement exhaust manifold will suffice and you can pick one up new for under $175, a little more if you have the CA emissions dual Cat version.
 
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