Front End Shake

My 2001 Wrangler has a 3 1/2 BDS lift and a set of 33" tires. Recently
there has been a vibration appearing to be at the drivers side front
between 35-40 Mph. I generally can steer out of the vibration or just hold
the wheel real tight and get through the vibration which is not apparent
once I pass 38-40mhp.

I'm just wondering what I might expect to hear when I take it to the shop.
I can't imagine wheel bearings, but I can imagine a tire spinning out of
round or perhaps I through a weight off the rim.

Any ideas?

Tnx, Rick

On Fri, 06 Apr 2007 23:37:38 GMT, Rick Gunderman <wa4rg (AT) cox (DOT) net>
wrote:

My 2001 Wrangler has a 3 1/2 BDS lift and a set of 33" tires. Recently
there has been a vibration appearing to be at the drivers side front
between 35-40 Mph. I generally can steer out of the vibration or just hold
the wheel real tight and get through the vibration which is not apparent
once I pass 38-40mhp.

I'm just wondering what I might expect to hear when I take it to the shop.
I can't imagine wheel bearings, but I can imagine a tire spinning out of
round or perhaps I through a weight off the rim.

Any ideas?

Tnx, Rick

THis is common and aften mis diagnoised. You have what I call a caster
"Death Wooble". It happens a lot with lifts that can change caster
angle of axle and also the bigger tires change the dynamics of forces
placed on front axle too and effect stabilty. SO will say you have
loose jiont or bushing which can aggrevate it but it is the fact that
the frontend is dynamically unstable to begin with that it shakes
whether the joints or bushings are loose or not. Typically with some
lift they tip axle forward to improve unjoint angel but the problem is
that it also decreases positive caster. Toe in also play a role here.
Factory alignement spec are for factory tires and wheel and when you
change hthis sometimes you need to tweak them some. If you want to
realy fix this you need to get your front end read to se what caster,
camber and toe-in spec it is set too now. If I can see this data I can
tell you what you need to change if your alignement tech cannot figure
it out. I used to align these things 20 to 30 years ago back when ther
was not computer racks and you had to understand how and why it works.
Todays tech do littlew more than follow a software program and are
lost when it does not fix it.
-----------------
TheSnoMan.com

SnoMan <admin (AT) snoman (DOT) com> wrote in news:3upd13tnl1r53aalsfp0gkgo3sekke475l@
4ax.com:

Thanks Snoman, I appreciate your comments and expertise. I had the jeep
lifted a couple years back and this is something that has just come about
lately. I can see why they call it a death wobble, whew, when it starts
shaking it's aweful; I'm just thankful it's only aweful at low speed. As I
said, once I get to 40mph things feel fine. I'm sure the tires don't help,
they're MT Baha Claw Radials.

There's a guy down the street that has a tire shop. I'll take it to his
place and get those readings. He well may know what to do but I'll run it
by you.

Thanks again for the assistance.

Rick

"Rick Gunderman" wrote in message ...

Thanks Snoman, I appreciate your comments and expertise. I had the jeep
lifted a couple years back and this is something that has just come about
lately. I can see why they call it a death wobble, whew, when it starts
shaking it's aweful; I'm just thankful it's only aweful at low speed. As I
said, once I get to 40mph things feel fine. I'm sure the tires don't help,
they're MT Baha Claw Radials.

There's a guy down the street that has a tire shop. I'll take it to his
place and get those readings. He well may know what to do but I'll run it
by you.

Thanks again for the assistance.

Rick

I had the same thing happen. New lift, new tires, no vibrations. As the 33
BFG's wear down, the vibration appears. I rotated my tires with the best on
front and the vibration went away. Try a new tire balance and your
vibration will likely go away also.

--
JimG
80' CJ-7 258 CID, HEI
4.56 Gears, Lock-Right F&R
35" BFG MT on 15x10 Centerlines
D44 Rear, D30 Front. SOA
Dana 300 w/4:1 & Currie twin sticks
Warn X8000i w/ dual batteries

00' TJ Sport 4.0L, 5sp
4.56 Gears, TrueTrac rear
33" BFG AT on 15x8 Eagle Alloys
D35 Rear, D30 Front. 3" Suspension Lift
Warn X8000i

Well, suspension lifts and big tires put a 'whole' lot more stress on
things so wear parts fast.

You could easily be looking at an out of balance problem which is
showing you a worn part early.

Rotating the tires tells you fast if it is a balance issue.

Even if it is just balance, I would be inspecting the tie rod ends and
steering components like bushings to see if wear does come into play.

If the steering geometry was off, I would have expected trouble from day
one...

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Rick Gunderman wrote:

My 2001 Wrangler has a 3 1/2 BDS lift and a set of 33" tires. Recently
there has been a vibration appearing to be at the drivers side front
between 35-40 Mph. I generally can steer out of the vibration or just hold
the wheel real tight and get through the vibration which is not apparent
once I pass 38-40mhp.

I'm just wondering what I might expect to hear when I take it to the shop.
I can't imagine wheel bearings, but I can imagine a tire spinning out of
round or perhaps I through a weight off the rim.

Any ideas?

Tnx, Rick

You might want to look into getting a steering stabilizer.
Just do a little research on them, check out the explination at this
link:

http://www.rockymountainsusp.com/W_stabilizers.htm


Aaron

Aaron wrote:

You might want to look into getting a steering stabilizer.
Just do a little research on them, check out the explination at this
link:

http://www.rockymountainsusp.com/W_stabilizers.htm


Aaron

A steering stabilizer is a simple shock absorber, nothing else. It is
there to mellow out any impacts the tires see when off roading or when
tracking on road ruts and to prevent harmonic vibrations from setting up
from slightly worn parts.

If you take it off and the front end shakes, you need to 'fix'
something. You won't get shakes unless something is worn or broken.

I recently found out that my CJ7 with it's 33" mud tires has never had
one on in the ten years or so I have owned it! It has a rod and an
empty tube sitting there where a shock should be.

I had bad shakes and wanders when I first got my Jeep. Once I 'fixed'
everything that needed it, it has run perfect since.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

On Sat, 07 Apr 2007 15:05:21 GMT, "JimG" <JimG (AT) nospam (DOT) com> wrote:

I had the same thing happen. New lift, new tires, no vibrations. As the 33
BFG's wear down, the vibration appears. I rotated my tires with the best on
front and the vibration went away. Try a new tire balance and your
vibration will likely go away also.

This could be a agrevating cause but the basic problem is a instabilty
in the front end that when it is given a reason to shake it can go
crazy. If the front end was stabile a balance problem would provide
likely more than a shimmy. I have seen front ends shake so bad that
you think something is going to break of fall off. This instabilty is
want lets it "run away" sometimes.
-----------------
TheSnoMan.com