Could it be the pressure plate?

 

Slipping = clutch. Bad vibration in 5th gear = possibly getting to a certain speed in your 5th gear causing you to get vibration from your wheels not being balanced? Good luck.

 

i bet its the clutch. t-case whines and grinds and clunks and all kinds of **** when its shot.....i've never seen it slip.

theoretically, it shouldn't be the clutch...the other parts of the drivetrain you havent upgraded(yet you throw a 3k super grippy clutch in) should break before the clutch....but this def sounds like the clutch.

 

It's the clutch.
It sounds like the pressure plate bolts broke and the clutch assembly has backed away from the flywheel. This explains the slipping and the odd vibration.

 

+1... Hate to say it, I know that's an expensive piece of clutch, but deff sounds like that would be the issue. I'd be a little upset with Exedy if you ifnd thats the case. You should call them or write them a letter explaining the disappointment, and inform them that you might swithc to another company (if you would do that)... They might just send you a new clutch in return for the burnt one.

 

well, good news is the clutch is rebuildable. bad news is it still isn't cheap.

good luck, contact mattgold here on the forum.

 

I am having thath problem right now, and it is the clutch, newone going in this week. You have been launching ya car a lot man, so I am not surprised.

 

similar problem but its not slipping its clunking in two gears and it doesnt clunk when i trun right or left! Here i posted it in evo general.........

I have an exedy twin disk that was put in two weeks ago and everything was fine up until now. I was driving around yesterday and 1.2.3 gears were fine then i put it into 4th and it started to "clunk" (best way i can describe it) the clunk sounds like its coming from the left front of the car. You can feel it in the clutch pedal and slightly in the gear box but, i think i can feel in the gearbox because of vibration (at least i hope), anyhow it gets even worse when you put it into 5th. As soon as i push the clutch in the sound goes away. The car is undrivable on the highway. Again it only does it in 4th and 5th and if i down shift into 3rd from 4th it will clunk for a few seconds then go away. I also checked if the flywheel was loose but i couldnt wiggle it and eveything seemed tight. I know exedy makes noise because it a twin disk but this is not just a regular twin disk noise.

i dont know if this helps but here are my mods

Mods
intake
recric. Valve
Intercooler piping
turbo inlet pipe
272's cams
full turbo back
ecu+