New problem...can't figure it out
 

So I might be alone in this category but hoping not. At high RPM my drive shaft has a really crazy vibrating...the DS is fine and where it's supposed to be and something is causing it to vibrate super bad. It's only at high RPM otherwise everything else is fine but it's super obnoxious...any help???:confused:

did u check underneath to see if anything is touching the driveshaft? could be exhaust touching it.

we went thru it 2 days in a row, nothing touching the drive shaft, and the transfer case is fine too...i just know it's not normal and its pissin me off

there could be something wrong with the driveshaft even if you can't tell by just looking at it. also how are you so sure its the driveshaft. iv never heard of an issue with an evo driveshaft

ie, are all the weights on the driveshaft, are the u-joints binding?

i don't think it's the drive shaft that's the issue, just with the high rpm's there is something causing the vibration to run down through the driveshaft...we put it up on the lift and held it at like 5K and heard the vibrating...however we're both stumped and we called 3 dealerships about it too

SmokedMustang had an issue with his driveshaft - ended up being a bearing. PM him - I am sure he can tell you exactly what he found.

https://www.evolutionm.net/forums/me...edmustang.html

agreeing w/ the possible bearing issue...
you arent going to be able to "see" it. If something is vibrating upon acceleration its a definate balance/tolerance issue w/ any part of the rotating assembly. Example: a really slight tire imbalance. You wont see it as some drastic ones... but once it hits just the right speed of rotation you feel the vibration.
Btw, i had this same problem in my fox body Mustang. I couldnt see it, but felt it. It WAS the driveshaft. but in my case it was both a housing/bearing issue AND it was slight bent. Replaced it and everything that houses it and it fixed it.

Rpm has nothing to do with driveshaft speed. Driveshaft speed is directly related to wheel/vehicle speed. If its only in high rpm and it doesn't matter what gear you're in, then its engine related. It could possibly be the clutch or the input shaft in the tranny. Those are the only non-engine components affected by engine speed (rpm).

they only time i'm noticing it is at high rpms just as i put the clutch down before I shift and also if i drop down a gear and the engine slows at high rpms

I felt vibrations thru the bolts in the drivers seat at about 4500-5K rpm when my balance shaft was 180 degrees out of sync as well. Did you change your cams or timing belt recently?? What mods are done? Did you get the car new? were mods on it before you got it?? Tell me more about the car and mods (if any). and how long you felt this vibration. I can help you figure this gremlin out. Had just about every one you can imagine. lol