I'm getting some vibrations from the rear end between 80 and 90mph. I'm hoping it is just a balance problem, but I'm wondering what other ppls ideas might be. Once I accelerate past 90mph it smooths out and there is no difference in the vibrations during accel/deceleration. Also, what kind of motor oil do you guys prefer?

Thanks for any input in advance,
Rice

 

I get vibrations when I'm full throttle and past 6K rpm almost every gear . If I'm not full throttle , no vibrations.

 

I only get vibration at a certain speed though, not at RPM range. I've tried shifting into 5th and even 4th at 80mph and no change in the vibrations. No difference under full, part, acceleration either.

Rice

 

In my previous cars, behaviour like this is fixed by getting an alignment. Vibrations only under acceleration _could_ be a sign of diff/cv/axle problems.

 

Are you running on stock wheels?

 

No, I have some 18" Konigs

Rice

 

I went through something similar to this. Here's my list of suggestions based on ease of implementation and likelihood of causing the problem:

1) Check wheel balance
2) Check tires and rims to make sure they're not out of round
3) Test drive car with different wheelset to see if symptoms persist. If yes, go on. If not, there's probably an internal problem with your tires, so replace them and see if the problem disappears.
4) Check driveshaft and 1/2 shafts for trueness and play. Pay special attention to the driver's side inner CV joint. It has gone bad on a fair number of cars earlier than it should.
5) Check rear subframe for tightness.

In order to remove vibration from my car, I needed new tires and new 1/2 shafts. New 1/2 shafts removed some, but not all of the vibration. The tires that were on the car (non OEM) had plenty of life in them and were balanced several times (even doing on-car balancing at a Lexus dealer), but the ride smoothed out completely when I replaced them with new tires.

 

Concure with CoralDoc.

Good Luck.

 

Thanks for all the great advice, I will be bringing the car in next week. I'll probably end up getting some new tires. What kind of tires do you guys recomend. I live in Texas so no worries about snow, just want a good summer tire I think. Also I've read a lot of ppl on this board saying they use Mobil 1 synthetic. Is that generally considered the best oil for our cars? And one last thing, have any of you guys had to order an owners manual? If so where did you get it?

Thanks,
Rice