Ever since I got my project car on the road it has a nasty vibration, especially in gear, off throttle that starts at 70+ and gets worse the faster you get, the irony is that it is more noticable when you let off. I switched to the wheels off my other car, which doesn't vibrate, still the same, I swapped driveshafts, still the same. The axle bearings are new. Could a worn tail shaft bearing in the trans cause this? Something tells me it may be in the trans because it was in the car when I got it, so its history/true mileage is unknown, whereas the engine, rear end etc do have known histories. I'm thinking its gotta be the transmission, but a second opinion would be nice before I start swapping things out.
thanks
Sean

 

On my step moms honda oddesy. We hit a large bump and ever since we hit it , it would vibrate over 65mph.

The dealership said that the weight was bumped out of position on one of the wheels. They needed to be rebalanced.

Hope this helps

-nick-

 

Yeah, a worn tailshaft housing bushing can cause this type of issue.

 

maybe the drive shaft weight fell off.

 

take a look at you driveline if the yoks are worn too much it will vibrate like no budys business. try a different drive line and see if that helps.
eric

 

he's swapped driveshafts and wheels ppl....

you know that the rear axle bearings are ok?

 

Yes the axle bearings are new, the U-joints on the one driveshaft were brand new as well. I'm almost positive its not in the front end, because the vibrations aren't transmitted through the steering wheel. Furthermore there is no feeling in the brakes (regular and e-brake) so it seems unlikely that its a bad wheel bearing etc. The fact that it is much more noticable on deceleration leads me to believe its something in the trans, or diff. Seeing as the drveshaft swap did nothing, and the joints on both I tried were tight I doubt its that either... Any other thoughts?

 

Sean, it's like when you go to the Dr's. "Doc, it hurts when I bend my finger. Yell Sean, just don't bend your finger"

You know I'm a smart ***!

I think the Panda is pissed because she's not the one getting a turbo transplant!!!!!!!

 

Check for worn shock mounts. Never know eh? Thats the only thing i can think of.

shake the following to check for play. "wheel bearings, front rack, shock towers and whatever else is linked to the tires."

I have the same problem but i know its because i need a wheel alignment.

 

shocks, springs, bushings, ball joints, tie rod ends, strut top plates, idler arm, wheel bearings, and pretty much everything else is new on the car. Although I haven't had it properly aligned, but i'm pretty sure the vibration is coming from the rear half of the car.
The shifter vibrates like crazy when its doing it....

 

so anyone else wanna confrim my trans theory?

 

Balanced driveshaft?
Tires bad?
Wheels balanced?
Axle bent?

 

Didn't have the driveshafts balanced, but having the exact same problem with two different shafts leads me to believe its not that.
tires are brand new and I balanced them myself (yes on a tire balancing machine )
The axles are straight as a arrow, I checked them when I had the rear apart to replace the axle bearings. Looks like a trans swap is in my future, luckily I have several spares and it doesn't take very long...

 

Transmission mount. Take a look at that and I bet you'd be surprised

 

Bingo! I was waiting for someone to suggest this as I was reading through the responses. Good call Chief!

 

Nope thats brand new and still in place too...
Thanks for the replies too....

 

I had a terrible vibration problem until I bought a NEW driveshaft from Mazda. New U-joints will NOT work because Mazda requires a tedious shimming and balancing procedure. Unless you KNOW that the other driveshaft is in perfect balance it is going to vaibrate unless it has the original U-joints and they are pristine.

Take the shaft to a balancing shop (they are fairly common) or buy a complete new shaft.

 

Could be the wheels you have.
I had all items checked: U-joints, tranny mounts, idler arms, etc.
Turned out to be the wheels (they were bent and could not be balanced) which I'm planning to have replaced soon.

 

I too had the vibration issue of any speed higher than 75 mph.

 

Not sure if this will apply to you, but I'll throw it out there just in case...

If you have drum brakes, and install aftermarket wheels, you need to remove the screw that holds the drum onto the hub (broad headed phillips screw). Otherwise, the wheel may hit against that screw and keep it from sitting flush against the hub. The factory wheels are designed so that the screw does not interfere with them.

 

Thanks for the input guys, but as my orignal post stated I had several different wheel/tire combos on the car to test that theory. One set of wheels was off my other 83, which has no excessive vibration all the way to 110mph....

 

I may be scrapping my RX-7. See the ZERO COMPRESSION thread. I would have an extra set of four Weds 14 inch wide wheels with 195x60 Potenza SR71 performance tires available.

 

Nice wheels, I'm sure you'll sell them easy enough, although If I were you I'd consider fixing it rather than selling.
Everyone is making simlar suggestions, but are you guys keeping in mind that the vibration is much, much worse on decel? Tires being out of balance etc, would vibrate either way, my car shutters/vibrates more when I let off the gas...

 

found bad front u joint on my driveshaft.....mazdatrix sells an aftermarket driveshaft with greaseable u joints.

 

Are they lighter by any chance?