Vibration/Shimmy at higher speeds?

[abguy]

Hi all,

I bought a 2005 Dreamcruiser convertible back in February and now has just under 60k miles. Overall it is in great shape. However, I notice that it had a shimmy going down the highway. In an effort to fix this the following has been done...

1) Took tires in for balancing. Shop noticed one tire had a bulge and another one had separated the belts. The previous owner stored the car a lot so this probably did not help the tires. I got 4 new tires.

2) Problem was better but persisted. I replaced both struts and shocks, front wheel bearings (had play when shaking the wheel- nut was loose on both fronts), front LCA assemblies (new bushings, ball joints, and sway bar end links). Tie rod ends appear perfect with no play in them.

3) Took car back to shop for alignment and balance check. They determined some of the brand new tires were defective and replaced all 4 and rebalanced.

4) On a side note, I have also replaced the upper and lower motor mount and spark plugs/wires when I got the car as they were original.

This is where I am at now. The car is much smoother than before, but around 70mph you start to notice a shimmy/vibration just like an out of balance tire. It gets worse and peaks right about 80. Weird enough, it starts to smooth out again above 85.

Does anyone have ideas on where to go from here? I would think if I had some kind of rim issue the vibration would also be there at low speeds too. As a test I placed car in neutral while it was vibrating and this made no difference so I know it is not the engine. Definitely something with suspension or driveline.

Thanks for any tips!

Kevin

[ptcruisersteve]

Originally Posted by abguy

Hi all,

I bought a 2005 Dreamcruiser convertible back in February and now has just under 60k miles. Overall it is in great shape. However, I notice that it had a shimmy going down the highway. In an effort to fix this the following has been done...

1) Took tires in for balancing. Shop noticed one tire had a bulge and another one had separated the belts. The previous owner stored the car a lot so this probably did not help the tires. I got 4 new tires.

2) Problem was better but persisted. I replaced both struts and shocks, front wheel bearings (had play when shaking the wheel- nut was loose on both fronts), front LCA assemblies (new bushings, ball joints, and sway bar end links). Tie rod ends appear perfect with no play in them.

3) Took car back to shop for alignment and balance check. They determined some of the brand new tires were defective and replaced all 4 and rebalanced.

4) On a side note, I have also replaced the upper and lower motor mount and spark plugs/wires when I got the car as they were original.

This is where I am at now. The car is much smoother than before, but around 70mph you start to notice a shimmy/vibration just like an out of balance tire. It gets worse and peaks right about 80. Weird enough, it starts to smooth out again above 85.

Does anyone have ideas on where to go from here? I would think if I had some kind of rim issue the vibration would also be there at low speeds too. As a test I placed car in neutral while it was vibrating and this made no difference so I know it is not the engine. Definitely something with suspension or driveline.

Thanks for any tips!

Kevin

I would suggest checking the gap on the spark plugs. I had vibration at high speeds and after replacing the spark plugs no more vibrations at high speeds.

[rob302]

Originally Posted by abguy

3) Took car back to shop for alignment and balance check. They determined some of the brand new tires were defective and replaced all 4 and rebalanced.

did they then do the alignment? or just blame/swap/balance the tires? did they give you a before/after alignment printout?

i would swap the front tires to the back, drive it, and note any change in how it feels. it's free, and a good step one. while each is off, make sure the area where the hub and tire mate is clean and burr free

[chuzz]

Might be a faulty cv joint in one of the half shafts.

[svtnos]

new axles...

[rob302]

Highly recommend you put the front tires in back and drive before changing axles. Free vs axles, seals, atf4 fluid + labor.

[ptcruisersteve]

Originally Posted by rob302

Highly recommend you put the front tires in back and drive before changing axles. Free vs axles, seals, atf4 fluid + labor.

I agree with Rob302. This was the first thing I did putting the front tires in back and drove it on the freeway. That didn't work so I was looking at unbalanced haft shafts, bad wheel alignment, and engine vibrations. Decided to go with engine vibrations and since the motor mounts had already been replaced I replaced the spark plugs that one of them had .075 gap on it. That fixed the problem and no more vibrations at high speeds.

[chuzz]

Oh, I HIGHLY agree with rob about rotating the tires first. I'm just saying if that's not it, you might want to check the axles. I'm NOT an ASE Certified Mechanic and would never claim to be one. Maybe one of the ones here will comment. LOL

[rob302]

Originally Posted by chuzz

I'm NOT and ASE Certified Mechanic and would never claim to be one. Maybe one of the ones here will comment. LOL

ironically, the only two ASE certified technicians on the forum are busy arguing about chrome plated toy car plastic hood decoration in the hotwheels thread right now.

[abguy]

Thanks everyone! Last night I rotated front to rear and it seems to have changed it slightly (perhaps) but overall still very similar vibrations. The plugs and wires are newer and I gapped them all properly. I can place car in neutral at the vibration speed and let engine idle down and vibration persists so I am fairly certain this is not an engine induced vibration. The alignment did come with a printout and the only adjustment required was toe in, the caster and camber were within spec. As far as the CV axles I have no noise at all when turning, could they still be failing? I do all my own work so the parts are the only cost, but I hate to keep replace the axles if they are not bad. Any way to check the CVs without removing them? The boots look perfect and car has 60k miles.