I have a 71 Skylark convertible, It's something of a Frankencar, full history unknown, with traces of red paint here and green paint there if you look real close but lots of new sheet metal and passable paint. My problem is a weird wobble in the car at right around 30 mph and up to 32-33 mph, then everything is smooth again. The tires and rims are all new as well as all of the steering components. The rear control arms are new too. The alignment specs are within tolerances. It's kind of strange, the wobble makes the car's body and steering column jiggle side to side a bit but only at these low speeds. I once owned an old early 80's short wheel base Chevy van that had a bad steering wobble at highway speeds. I corrected the problem by installing a steering stabilizer (horizontal shock absorber). This wobble reminds me of that problem but not as severe. The only other driveline vibration I can report is that if I go above 65 mph the car starts to shake a bit. It gets a vibration that others here have reported too - it feels like it starts at the front and works it's way to the back of the car, then starts at the front and does it all over again until you drop back down to 65. In one way it sucks but then again it helps me to not speed so much. Your feedback and ideas are appreciated.
Does it feel like the rear of the car is wagging left to right a little at the slower speed? I know you said the tires/wheels were new, but I have had a bad tire that was fairly new and felt similar to what you are describing. Visually the tire looked fine. Figured it out when I rotated the tires from front to back and vis versa. The wobble changed. I had a friend drive very slowly in a tight circle while I observed the front tires you could see the tread deform a little. Turned out the tire was separating. Yokahoma tires btw. Good luck with it.
Tum ting wong Sound like its coming from the back. I would check the run-out on the rear tires while still bolted to the car, and then spin -em up on a balancer. A bent axle can also cause this, so check the flanges and make sure They are straight. As far as the high speed vibration goes, it sounds like all your tires are out of balance, so it wouldn't hurt to re-balance the fronts also, you may have thrown a wheel weight or 2, or 3... Make sure whoever balances them checks for run-out/wobble when they spin them.
I spent $ 850 on some new tires that had Goodyear written on them. They had different shakes at different speeds. I worked as a tire guy back in the day. The general rule is...If it is on a spin balance,and looks a little out of round,it is because it is. The new tire guy just balances your new junk tire so it is ready. The old timers actually have machines to make the junk tire round. They cut the high spots out of new tires so they spin true. I quit buying tires where they would not let the customer watch the balancer. It was just too expensive to buy junk. I have had 300k cars that drive like new with a good tire guy.
I'd check the idler arm, tie rod ends, drag link and lower ball joints. Eliminate them for sure. I've seen some 4x4, like you mentioned, have a little slack in the front end with worn parts get that kind of shake. Sometimes we could dial it out with a little more toe, in or out didn't matter, just a little more to keep tension on the front geometry. Sounds like you might have a touch of it.
I have the same problem at about 30 to 33 mph. Started after mounting new tires. I'm suspecting poor balancing of one or both fronts.
I raised the front end, one wheel at a time and gave a pull top to bottom and the left to right. I have a little bit of excess bearing play on one side and it feels as if I may need to inspect the drag link and idler arm. It's a shame, these are all new parts. I am also going to have the front wheel balance checked. The U joints are fine, I just had the trans mount replaced. I have the same problem at about 30 to 33 mph. Started after mounting new tires. I'm suspecting poor balancing of one or both fronts. Your speed/symptom matches mine exactly.
Did you ever determine what that front end wobble was? Mine seems to be worse. Front tires re-balanced so it's not that.
NTB sold me a new set of tires and done a terrible job balancing. I took em elsewhere and had them rebalanced, now,,,,,smooth as butter.:laugh:
Update to this old thread. I'm not sure what the (wobble) culprit is but things are improving. About a year ago I replaced the old rear tires with a pair of Cooper radials. Still wobbling. Then I had the drive shaft sent out and balanced, this helped a bit with general ride quality but still not a cure all. Most recently I had the single exhaust upgraded to a dual exhaust and at the same time I had a pair of stock frame stiffeners installed at the rear control arms. Now the wobble is almost completely unnoticeable. I really have to try and force it to happen. As far as the high speed rhythmic vibration that seems to travel through the car from front to rear over and over again... It's my motor. I sat in the car one day with the car in park and just slowly ran it up through the rpm's, at a little over 2000 rpm's it starts to vibrate ever so slightly and if you hold it there it works it's way through the length of the car. At speeds up to 65 mph the car is smooth as can be but if you push it up to 70 or more the drive line vibration starts.
