Header and Death Wobble

[cherokee pilot]

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

 

[xjtony]

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.

 

[mbryson]

Death wobble from tires is likely a belt separation or similar tire defect. If you've changed tires and don't have death wobble any longer, I would guess you have a tire defect.

 

[N-Smooth]

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.

 

[cherokee pilot]

Death wobble from tires is likely a belt separation or similar tire defect. If you've changed tires and don't have death wobble any longer, I would guess you have a tire defect.

But once the tires wear down the problem returns.

 

[cherokee pilot]

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.

But my header is cracked.

 

[DaveB]

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.

 

[mbryson]

But once the tires wear down the problem returns.

Find whatever is loose, worn or aligned improperly. You'll get it

 

[XJEEPER]

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.

 

[spaggyroe]

I'm a believer that all death wobble issues are ultimately an alignment issue. Loose tie rod ends, track bars, control arm bushings, ball joints, worn shocks or tires just set things in to motion.

Source:
My head