Question1994 Plymouth Voyager LE 176k, 3.3L, 4-spd trans
The expert whom I used to ask question is not available anymore under plymouth. I am asking you now as I believe this van is sister of Chrysler town and country. Thanks for your help!
The van shudders at front end at speed of 40mph; at lower or higher speeds, it runs without any problem. I am thinking of bad ball joints and/or CV joints. All CV boots are intact. Can you give me an idea on what are possible culprits and how to identify the culprit?
AnswerHi Shafique,
I am not highly experienced in front end vibration problems but let me give you a couple of ideas. I doubt it is CV's unless you also hear them making noise at other speeds, particulaly when turning. The ball joints can be assessed by lifting the wheels and seeing it the tires move back and forth when the lower edges are shaken transversely.
I would also suggest that if you had access to a dial indicator that you measure the radial variation ("runout") of the surface of the tires in the middle of their treads. If it is more than 0.04" then you could go to a tire shop and have the tires that don't meet that spec. checked for any tread attachment issue and if they pass that inspection then ask them to "match mount" the tire to the wheel. That approach measures both the tire and wheel radial runout and matches the positioning of the tire on the rim to cancel out as much as possible unroundnesses. The shop should be queried as to whether they can check the tire/wheel runout if you don't have a dial indicator.
If the runout of the tires is o.k. then you might try to get the tires re-balanced while on the front end (using a dynamic on-car balancer) so as to deal with imbalances that exist with the rotors which of course are not involved if you balance the wheel off-the-vehicle.
This match mouting/dynamic balancing approach was suggested in my '89 technical service bulletins issued by Chrysler for front wheel drives that vibrate in the range of 45-65 mph only.
Roland
