front shake

[RJfestiva]

Shakes bad at 45mph, and worse at higher speeds.

Work Done:
I've replaced the right side CV Joint because it was making noise when turning.
Replaced broken right-side, and front motor mounts with new ones.
Replaced struts, and rear shocks.
Replaced tires and wheels with Alum 14".

Replaced rear mount with a used one because I couldn't find a new one. No rear mount was available at part stores, or the dealer. It has some small dry cracks, but I thought it would hold until I fabricated a replacement.

Troubleshooting results:
While car is on jacks with no front tires;
1.) Engine doesn't shake in park, or neutral while idling, or high rpms.
2.) In Drive the engine wobbles while idling.
3.) With a slight increase in throttle it shakes worse with no wheels than while driving.

Any insight will be greatly appreciated

[69shelby]

probable the front wheel bearings.

[gdawgs]

Try doing one side at a time to see if you can narrow it down to one side.

Basically do the same thing you are doing but instead of jacking up the whole front end, jack up one side and place it on a jack stand. Leave the other wheel on the pavement. Get in, start it up, put it in gear and see if she shimmys.

Then try the other side. Maybe it's just one side, maybe both.

With the wheels off, if it's shaking as bad as you are making it sound, you think you would see something out of the ordinary by watching it. But not necessarily.

[htchbck]

jack up one side and place it on a jack stand. Leave the other wheel on the pavement. Get in, start it up, put it in gear and see if she shimmys.

I could be missing something, but if ya have one wheel on the pavement and you put it in gear, with the clutch you're fine, but if you let off the clutch, you'll be screwed cause the one wheel on the pavement will bite and throw the car off the jackstand, right?

[packrat427]

No it won't come off as long as you are careful and don't smash the gas or have a limited slip diff.
Just ease the clutch out easy ,and the one wheel will spin freely , enough to pin point the problem .
I have done it to find a bad rotor .

[gdawgs]

Yes it will stay on the stand. One thing to note is that when only one wheel is spinning, the wheel is spinning twice as fast as what the speedo is reading.

When I bought new tires for our MG Midget, no one who sold tires had equipment that could handle the wheels(they have a small center hole, so they didn't fit on any of their machines). So my dad and I mounted them ourselves. Of course no one had a balancer that the wheels would fit on either. So we took it to a mechanic friend and we balanced them the old fashioned way. He had a balancing device that clamped onto the outside of the rim(where the wheel weights go) then we jacked up one rear wheel at a time. You basically run the wheels and make adjustment until the car didn't vibrate anymore. One of the best balance jobs I've ever had done. I've had some pretty poor ones done on the automated balancers.

Anyway, jacking up one wheel at a time can be a good troubleshooting tool. Just be careful! Don't get under or in front of the car while running and make sure other people are clear as well.

[RJfestiva]

Try doing one side at a time to see if you can narrow it down to one side.

Basically do the same thing you are doing but instead of jacking up the whole front end, jack up one side and place it on a jack stand. Leave the other wheel on the pavement. Get in, start it up, put it in gear and see if she shimmys.

Then try the other side. Maybe it's just one side, maybe both.

With the wheels off, if it's shaking as bad as you are making it sound, you think you would see something out of the ordinary by watching it. But not necessarily.

I hadn't thought of doing one side at a time, thanks for the tip.

[htchbck]

No it won't come off as long as you are careful and don't smash the gas or have a limited slip diff.
Just ease the clutch out easy ,and the one wheel will spin freely , enough to pin point the problem .
I have done it to find a bad rotor .

Oh yeah... forgot about that. I was just thinking back to a time when my buddy was trying to pinpoint some axle problems in his acura, and he wound up trying that and crashing his car off the stand into the garage door... but he had LSD on the car, so thats the difference.

[RJfestiva]

OK, I replaced the driver side CV joint mainly to eliminate it as part of the problem, and it was in need of replacing, still usable though, but didn't solve the problem.
I put it in gear with only the left side off the ground, still shakes, with only the left side up no shake.
Even with a questionable rear mount you'd think the side with 2 mounts would shake less the the side with only 1 mount, but it's just the opposite.

Now is it possible for the transmatic to be the root of the problem? :?

[RJfestiva]

Since I couldn't find a rear mount, I didn't bother to look on the Motorsports web page, I looked at it today and found the picture for the manual rear mount, to my surprise the picture matches my mount, what gives? Why specify manual if it will fit automatics as well? BTW the front mount is identical too!

Competition Mount #2 picture here http://www.festivamotorsport.com/per...transaxle.html

[RJfestiva]

Testing with the one wheel off the ground was a good idea, but because the driver's side shaft is short the hanging angle is too acute and was causing the shake.
I lifted the control arm with a hydraulic jack and the shake disappeared.
Don't get me wrong, it still shakes (actually a vibration) at high speed, but the left cv joint was causing a shake at idle, and at 30mph, I just made it worse by not supporting the suspension.
The vibration should stop once I replace control arm/ball joints, sway bar bushings, rebuild steering rack, strut mounts, and that used rear motor mount.
Thanks, to all who helped, and I'll post again when the TO DO list is completed.

[RJfestiva]

Update
I didn't need to replace the rack, but did replace the tie rod/ends, strut mounts, and control arm/ball joints which came with new sway bar end bushing.
The high speed shake begins at 55mph.
Next I'll check wheel balance, then bearings, if that doesn't solve it, I'll start the tire/wheel runout tests.

There's one question I'd like to put to the forum.
When I took it for alignment the Tech said (and I saw it on the display) that the camber is beyond the strut mount adjustment (rotating the strut mount 180°.) He said he could file the strut shaft holes in the mounts to compenate, but I didn't want to do that.
My question is; is this causing, or making the shaking worse, can a strut tower brace help?

[Tom]

It sounds to me like you have a bad bearing where the axle's goes into the trasmission, probably the side that shook when it was up.

The one in the transmission.

[ericsmith32]

On my dad's Festiva it had a shake that even rebuilding the front end didn't help. The cause was a slipped belt in the tire.. actually more than one. His started to shake about that speed as well. They were stock 12" 's but it can happen to any tire.

[5.0zone]

Yep, I bet its the tires.
I had one this summer that was out of round and it shook the car real bad at 60 mph.
I took the car to have the wheels balanced and when the guy put the right front on the balance machine you could see that is was out of round as it was spinning.
Swapped that one tire with one from my parts car and the vibration went away.