Heep question. Braking wobble

[shady]

My mom's been having trouble with her 2000 Heep Cherokee.
When shes driving at 55-70 and brakes firmly, doesn't even have to be hard, the front shakes like death wobble. Around town and at lower speeds there's nothing at all though.

Letting off the gas without braking is smooth, cruising up to 80 is smooth, light braking around town or highway smooth. Moderate to heavy braking at high speed shakes like crazy.... ?

Any thoughts? All I can think of is ABS issues. Light light is on in the dash. But there's no issues braking at any other time so...?

 

[shady]

 

[diesel4me]

Video doesn't really show much..
I'd be jacking it up and checking for loose tie rod ends,pitman arm and all the steering linkage for wear--loose wheel bearings,or rotors that are warped,heat spotted,or loose caliper mounting bolts--then if all those seem good,you'll have to inspect the rest of the brake system..

Sometimes not enough caster will make a "brake shake" at higher speeds..but usually its worn steering or suspension parts letting something "vibrate" back & forth rapidly..

 

[Justin V]

Track bar

 

[shady]

I checked all the steering rod joints yesterday. And I had thought warped rotors but I don't feel the usual symptoms at low speed for that.

The caster angle thing has me thinking some.. I'm wondering if it's worn out suspension bushings maybe . Maybe the heavier braking at speed is letting the axle rotate some due to more force on the old bushings.... ? ( Thinking out loud basically..)
It drives around pretty darn nice in all other situations. And I can feel it some when braking HARD at around 45 too.

One thing I did find is the driver's side front abs sensor cable was rubbing on the axle shaft knuckle. I think it wore into the wiring inside.
I figured it was just causing the light, but now I wonder if it's giving the front odd uneven braking

 

[shady]

Track bar

That's the side to side one right?

 

[Justin V]

Track bar

 

[Justin V]

Yes

 

[Justin V]

It locates the axle under the truck for side to side movement. It could likely be a combination of things. Upper and lower control arm bushings could be slightly worn, with a little bit of rotor warpage to set it off, but the track bar is going to be a big part of the equation to fix it.

 

[shady]

I'll have to see if I can just find a kit with all the front suspension bushings and do it all.

 

[shady]

Looks like a full front end poly kit is only $100...

 

[frankin5]

Rotors will cause wobble when applied at speed if warped.

 

[shady]

Rotors can be felt lightly at slow speed too if warped. But it doesn't have that....

I'm thinking the bushings. It could probably use them anyway

 

[83ChevyK5Blazer]

Trac Bar like Justin said, my GC was doing the same thing and I thought the rotors were warped, replaced the trac bar when I put the lift on and now nothing.

 

[shady]

Track bar helped, but didn't take care of it. So I changed all the control arm bushings and it's way better.