Not so good vibrations...

[Jo3f1sh]

:3d_frown: Well, today didn't go quite as planned...After the car got out of the booth last week, we swapped over the suspension (stock struts with H&R springs...obviously not the right way to go) wheels and exhaust from the loaner Supra is was borrowing. Even though it was in rough shape, it ran quite well and drove VERY smooth on the highway. HOWEVER, after swapping the suspension over to mine with no changes, i'm getting a horrible vibration in the steering and throughout the car over 50 mph. So, i figured i'd start at the wheels and work inward, so i took the car to get the tires balanced all around and found that my right rear tire had a nice huge gash in the inside sidewall i hadn't known about. Nice surprise. SO, two new tires later AND a full 4 wheel balance, the vibration remains.

Strange thing is, it's not constant. It's almost a pattern of vibrations going in and out ever so slowly. Since i've ruled out the wheels/tires, i can only assume it's a bushing or possibly a bearing gone bad, but i find that strange since my car was driving smooth before the swap, and the loaner was driving smooth with this suspension. Any ideas on what this could be? It's emanating through the steering wheel, so i believe it's coming from up front.

:1zhelp:

 

[suprakid24]

mine has vibrations too, especially if I'm going pretty good (50+) and throw it in neutral to roll, it vibrates like crazy. I too just had my tires aligned, so those should be good, I'm sitting on a tein setup, and I also have an aluminum drive shaft.

 

[Jo3f1sh]

Strange. The drive train is completely stock here save for a shortened shifter. I'm REALLY hoping it's a simple bushing replacement that's easy to swap out...

 

[jdub]

Does it vary with rpm? At what speed is it most pronounced?

 

[Jo3f1sh]

The RPM's actually make no difference. I could let it idle at speed and it would still make the same vibration.

It's most pronounced between 55-65 mph.

 

[91 mK3]

hay mine vibrates to. then what i usually do is i hit the brakes pretty good and it goes away. of course, my rack and pinion bushing are bad and it has a lot of play, so im leaning more towards that. only thing i can really think of is to mouble check your work. are your struts bad?

 

[Mrbaboon]

Make sure your center support bearing and driveshaft are bolted to the body and differential, respectively. I had this problem, turns out my driveshaft bolts on diff were loose.

 

[jdub]

The speed is actually more important...check the drive line bolts per above.

Have you double checked the all the bolts on the coils/shocks?

Bad wheel bearings can cause a vibration as well.

 

[Jo3f1sh]

I double checked the bolts for the front suspension and they were all tight. I've had drive shaft vibration before in my Mustang, and it feels quite different. It's actually more towards a shaking than a vibration in nature. I'm suspecting bad wheel bearings...which i've read can't be replaced on 87 and later Supras....per the Haynes manual....

 

[Piratetip]

I had a similar problem.
Bought a full set of Timken wheel bearings.
Before I had a chance to put them in I got all new tires, which ended up solving all the vibrations.
Bearings are still in the boxes.

 

[jdub]

I'm suspecting bad wheel bearings...which i've read can't be replaced on 87 and later Supras....per the Haynes manual....

Not true...dump the Haynes manual
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FA&P=10

Pages FA-10 to FA-14
You will need to take the hubs to a shop with a press to remove/re-install. The back is in a different section in the TSRM (RA-9 to RA-13), but is the same in that the hubs have to be removed.

It could be the tires themself like Piratetip alluded to...out of round tires will vibrate like crazy.

 

[Jo3f1sh]

lol...it's actually helped me quite a bit...but now that i have that link, i probably won't need it anymore.

The thing is, these wheels/tires were on basically the exact same car and it was fine. I also just had them balanced, so i'm not sure if they're the source of the problem any longer. Definitely not going against your advice, but i'm just curious.

A friend told me to check my sway bar connections and make sure they're tight (even though i assume all that would do is give the car a bit more roll than usual) and the tie rod ends (although i don't think we touched them).

 

[jdub]

Balanced and out of round are two different things when you're talking about tires.
But, you are correct...coming off the same car should not cause an issue this bad. Plus you have two new tires too.

 

[Poodles]

how long did the car sit?

flat spots will balance, but as they're out of round they'll vibrate like mad...

 

[IJ.]

Rear section of the DS out of phase will do this as well.

 

[GrimJack]

Standard or auto transmission?

If standard, when you are idling at speed, is there a difference between neutral with your foot off the clutch and in gear with your foot on the clutch?

You did check your lugnuts, right?

Jack up the front of the car and put it on jack stands that aren't on the suspension. Grab the front wheel and shake, see if there is any play. Do side to side, up and down, etc.

Do the same to the rear of the car.

Speed related usually means it is something that rotates, and the speed where it occurs is the correct frequency to make it noticeable.

 

[Jo3f1sh]

It's a stick. I haven't tried that yet, but i do it tonight and see what the results are. And yes, i've taken the front wheels on and off many times and made sure they are snug.

I did however notice this: when i jacked the car up and took off the wheels once, i could grab the front assembly and move it up and down ever so slightly. I would say maybe a few millimeters worth of play...does this indicate a worn ball joint? The boots look good, but that's about all i can tell. Will that minute amount of play cause the shaking/vibration?