I have been noticing that my car has been vibrating in third gear(it seemed to be worse between 3000 and 4000 rpm's). Well today it felt like it was vibrating in fourth gear also. I was cruising down the highway and I could feel the vibration in fourth. I put the car in neutral just to see if the vibration would stop. The vibration got much worse when the car was in neutral and I was going about 60-65 mph. Can someone please help me out? Am I about to lose my transmission?

 

Sounds more like a U joint or a rearend problem since it did it in N. I would change the u-joints first.

 

Well, I changed my universal joints and the problem didn't get better. The only thing is it might have reduced the vibration when I put the car in neutral. Now it vibrates going at any mph in neutral the same as it does in drive. What should I look into next? Please help me if you have any ideas. First and second don't seem to do it as bad as 3rd(the worst) and 4th.

 

Dude.. whats that garbage in your signature?

 

I would check the transmission tailshaft and the rear
end pinion shaft for side-play (left, right, up, down).
These should have zero slop.

Also might check the integrity of your trans mount, if
(say) the rubber has turned to gum and let go, it can
make some nasty vibration (as well as bumping when
you get on it).

 

I will check the tailshaft but the mount is a brand new poly mount.

 

Does this brand new poly mount coincide with the vibration
starting (or, starting to be noticed)?

I know some complain about poly mounts transmitting more
vibe to the car.

 

I honestly don't know because the night I bought the car I noticed that the transmission mount was broken so I replaced it that night. Therefore I have nothing to base it on. The guy that had it before me drove the car with a broken trans mount for a while. He said he thought it was the exhaust hitting the cross member. So judging by your last post my tailshaft could have been hitting the floorpan for a while. My car has a shift kit in it so it would hit on take off and when the car shifted to second gear. If it is the tail shaft area what are my options?

 

Well, I took the driveshaft out and checked the pinion for slop and there is none.(whew). I move the trans tail shaft and it moves just a little.(maybe 1-2 mm) I called the guys at Racing Transmissions and asked them about 50 questions. They suggested that I get the driveshaft balanced and get the rear tires balanced. I am goint to get the tires balanced tomorrow and the driveshaft balanced Monday. I really really hope this fixes the problem. If someone has other suggestions please let me know I am open to everything. Thanks.

 

Dude... it's a quote from someone that claimed to be a straight "A" student and then posted that comment. I thought it was funny and ironic.