Really Really Bad Vibration - Jeep Comanche

I have an 88 Jeep Comanche, 2wd, 6 cyl, 5 spd, that has developed a
problem. When travelling over 70 kms/hr, if you hit the right
combination of bumps, the entire truck starts to shake insanly hard
(it shakes so hard that it has broken my exhaust in the past). Once
the shakking starts, the only way to get it to stop is to slow down
below about 60 kms/hr. You don't actually lose contol of the truck,
just you have to get it stopped as soon as possible because it just
keeps getting worse and worse. This problem has been going on for
quite some time now. In attempts to fix it I've replaced all shocks,
steering dampener, track bar, and anythng else that was at all
questionable in the front end. I have also tried several different
tire and wheel combinations, some make the problem better or worse,
but none fix it.

My passengers have started to refer to the problem as "the death
bounce".

If anyone has any suggestions on this problem I would greatly
appreciate the help.

Thanks,

Brent

On Tue, 2 Nov 2004 17:00:20 UTC (Brent) wrote:

> I have an 88 Jeep Comanche, 2wd, 6 cyl, 5 spd, that has developed a
> problem. When travelling over 70 kms/hr, if you hit the right
> combination of bumps, the entire truck starts to shake insanly hard
> (it shakes so hard that it has broken my exhaust in the past). Once
> the shakking starts, the only way to get it to stop is to slow down
> below about 60 kms/hr. You don't actually lose contol of the truck,
> just you have to get it stopped as soon as possible because it just
> keeps getting worse and worse. This problem has been going on for
> quite some time now. In attempts to fix it I've replaced all shocks,
> steering dampener, track bar, and anythng else that was at all
> questionable in the front end. I have also tried several different
> tire and wheel combinations, some make the problem better or worse,
> but none fix it.
>
> My passengers have started to refer to the problem as "the death
> bounce".
>
> If anyone has any suggestions on this problem I would greatly
> appreciate the help.

That's more commonly refered to as "death wobble" and there are 2
basic causes: wheels out of balance and worn parts. Tire balance is
critical, especially as parts start to wear. The steering damper was
a good place to start but think about it for a moment: One that is
working right will lessen the effect by masking it a bit but it
doesn't fix the cause. Worn tie rod ends or worn ball joints should
be checked with wheel bearings next in line as potential causes.

--
Will Honea