Drivetrain noises and vibration

[street_lethal]

I had my t-case, viscous coupling unit, and rear diff replaced about a year ago due to dumping the clutch. Since then I have not launched my car. I recently have been experiencing a lot of clunks when I shift coming from the back mostly. Also when I drive on the highway I get a very bad vibration coming from the back, and it acutally causes my car to slow down. I think my rear diff is locking up on me. Has anybody else come across these problems yet? Any way to fix this crap without having to replace it all again?

[SicLanEvo]

Have you ever had the rear diff fluid changed? also maybe the bearings for the driveshaft are going bad....this was a problem on the 3000gt vr-4s over time. AWD cars make a lot of different sounds the clunk is normal from what i understand. if your car is slowing down on the highway and there is a bad vibration i would not be driving it all. You just spent and arm, a leg, and possibly a left nut to fix the other issues with your drivetrain...why do it again because of a bad vibration. Contact shep trans and get them to rebuild your rear diff after you make sure that is the issue....get it somewhere fast and on a roll back before you do more damage.

[street_lethal]

Its probably been about 10k since the fluid in my t-case and rear diff has been changed. I dirive hard and speed shift but I never launch it. Bearings for the drive shaft? Possibly. I'm gonna take my car in to the dealer and have them look at it. Any idea on about how much shep trans charges to rebuild the rear diff?

[SicLanEvo]

its not much check out his website. the worst part is downtime and shipping depending where you are.

[Ignitiondelay]

the car needs to be carefully inspected by a professional. you shouldn't be driving on the highway is the car is behaving erratically. it is very dangerous.

do you have the invoice from the work that was done? if so, let us know the details.

[MichaelFoster]

Good day. Maybe it's the drive shaft. Check it. Maybe something is loosened and it's hitting your driveshaft. Good luck.

[rookhoe]

Michael, I saw that you edited your other post. Still hoping that we can help you with your problem but we cant really do that unless we have some more info on whats going on. Start a new thread, or PM me what is going on. I really dont think the problem is your driveshaft.

[street_lethal]

sorry i know that this is an old thread. I changed my drivetrain fluids with amsoil stuff. the car seems to run smoother. I believe the whine is from my drive shaft ( i read some where that a little whine is normal...but mine whines a little louder than normal when driving at all speeds). The car does make loud clunks when i shift sometimes....but i read some clunks are normal too. The the bad vibration seems to have gone away. Every now and again i still get some vibration when cruising over 75mph. it doesnt slow me down, but i let off that gas when this does happen, and the problem goes away temporarily. I plan to have my t-case and rear diff rebuilt eventually. does anyone think its safe to race?

[rookhoe]

i wouldnt race it. im about 85% sure thats a sign that your t-case is about to go. racing it would only make it break sooner.