Expert: Chris Fortunato Date: 5/30/2007 Subject: 1996 Grand Cherokee, violent front end shake
Question Hi Chris, when applying brakes at 55-65 mph the front end shakes violently, like the whole front end feels like its coming apart. I thought a wheel was coming off but all checked ok.
This is my 1996 Grand Jeep Cherokee with 172,000 miles.
Exact same thing had happened with an earlier model which, after several days resulted in brake failure because of locked up caliper which boiled the fluid. So, last night I replaced rotors, calipers, pads thinking same solution to same problem. Unfortunately, the problem has not been resolved, the brake job had zero affect. Good thing is that I did it myself so the hit was minimal.
The problem seems to be originating from left front.
Tires are in good condition and have no signs of irregular wear. I've never used any kind of fix-a-flat, never had any issues with tires.
Any help would be greatly appreciated.
Quinton Brantley in NC
Answer Hi Quinton,
Only on braking? If so, you were in the right direction, initially. However, if nothing changed, then there's obviously something else going on. Have you tried rotating the tires? Although you may not have used fix-a-flat, a broken radial belt or water inside the tire can cause very similar concerns.
Aside from that, I would perform the normal steering/suspension checks -- no play in the ball joints, very little play in the track bar, and a solid Pitman arm. Similarly, check the front wheel bearings -- although they rarely fail without making horrendous roaring or grinding noises, it has happened. Lastly, make sure the Steering Damper is firm and not leaking... and I've seen more than a few that have failed without leaking.
Most of these vibrations are not *normally* actuated by brake application, though. Does it happen when you hit a bump at that speed? Still, braking does change the front geometry, so if the vibration is 3x the speed of the wheels (roughly), then you have be looking at a loose pinion nut, a worn front u-joint, or something else.
Regardless, this may be a portent to something dangerous, and I wouldn't hesitate to take it to a reputable shop. At least, swing by one and have the shop foreman, or even a technician, climb in and experience it first hand. Offering to buy the person lunch often helps to get volunteers ;)
