rx7_1

ok here's the back ground. i just put in a new tranny (blew up the last one ) and ever since we finished there has been a wierd vibration while driving dont know what it is. the car runs great and shifts great. i went back and checked the drive shaft and it is bolted in just fine. i also checked the motor mounts to make sure we tightened them back and they were. i changed the rear diff. fluid one day after the swap and it is fine. we made sure and double checked everything as we went on with the swap and everything was put back together. hopefully you guys can give me so idea's on what might be wrong so that i can fix it. thanks matt

rx7_1

oh and i forgot to add that i had a blow out on the interstate on the back right tire and had to slowly drive to the next exit. could it be that my alignment or balance could be off so bad that is would cause it to vibrate?

Sideways7

iTrader: (7)

If the dirveshaft isn't bolted up the same exact place it can cause vibrations. I believe most auto shops can balance it if thats your problem, but what for confirmation first.

Vespizzari

I would bet hard currency it's a flat spot in the rim, or a serious alignment/balence issue. Any hit hard enough to blow a tire, or any time spent driving on a flat will cause issues in any car.

Mazda99Nikon

Alightnment/balance issue. When was the last time you had this done? It's worth the cost even if it doesn't fix the problem if you haven't done this in the last 15,000 miles.

Sideways7

iTrader: (7)

Even tires can cause this, as well. When I bought the car the fronts were starting to seperate and caused a huge vibration in the steering wheel.

RN's X-7

the rear can't be aligned and does not have a camber adjustment. Id go for the flat spot and or the drive shaft out. My two cents (haha). Good luck finding the problem, makes ya want to shoot the darn thing

jhammons01

In the FSM there is a procedure for balancing the Drive line where it connects at the rear Yoke. There are washers placed to balance it. I bet you didn't take notice of the washers when you took your drive shaft out.

The tire out of balance would be the easy fix however unless the guy just missed whil wpin balancing the tire then it shouldn't be the culprit. Even with a bent wheel. IF you want to check that theroy just rotate the wheels and see if the vibrations follows the wheel to the new corner.

rx7_1

thanks guys. i know it's not a tire or balance issue had 2 brand new tires put on the back today na dboth balanced. and i (personally) put the washers back on the bolts for the driveshaft. could the washers been put back on the wrong side of the crive shaft. for exapmle when i put them back on i put the bolts threw and then put the washers on and then the nuts could that have anything to do with it? anyway thanks for the help guys.

ProjectR13B

iTrader: (1)

double check the front tires. mine was vibrating then the tire bounced off while i was going 70. luckily the only damage was too the rim and my brake rotor.

jhammons01

The washers are the balancing weights. Even if you put them back on yourself did you put the right ones in the right spot? or did you just grab a washer (unkowingly of course, ne trying to bag on ya') and put it on a bolt and stick it through???

Ya gotta examine that aspect of it.........

jhammons01

oh snap! have you changed the u-joints yet? If not your 15 year old u-joints are shot.

rx7_1

ok thew u-joints are new becasue they were replaced right before i baught the car. i know that they were becasue i got the paperwork from him on all major repairs. the washers that went back in with the driveshaft were the same ones i had on before but your saying that they could be wrong end of the bolt. anyways the drive shaft comes out tom. so i'll hopefully figure this out. i looked at the exhaust and there a rubber hanger missing so i went and picked one up today. so it should be ok tom. thanks for all of the help guys. helped out alot.