Help me figure this out, please.

[Bimmerboy91]

so ive been hearing this damn clunking sound for a long time and i cant really seem to find out what it is, because my guibo looks fine. tell me what you guys think. i have some more info about my problem in the description on my vid in Youtube

heres what my guibo looks like and my transmission mounts.



and heres the vid link:

http://www.youtube.com/watch?v=E-i_9sL5mGU

id really appreciate the input from you guys.

thanks

[pe2one]

i think its the drive shaft center suport making that clunking sound

[Bimmerboy91]

i thought of that too, but i also thought that if it was the ccb, that i would get a ton of noise and vibration at higher speeds and ive been up to 110 mph here and the only vibration that i get is from the front wheels. which is another problem that im not sure of.

thanks for the input, definatly something i should keep in mind.

[AlpineIS]

It's hard to tell from the short vid but another thing to look at are the u- joints on your driveshaft. I currently have whine from the rear as well as a clunk upon sudden deceleration and acceleration. I thought it was the diff (guibo and CSB are fairly new) that was bad but it turns out one or both of the u-joints have called it quits.

[Mike325]

Is the noise engine speed related, or wheel speed related? Sounds like a busted CB or the u-joints, like mentioned eairlier.

[Bimmerboy91]

the sound, i can hear/feel it right in the transmission tunnel. its more of a clunking sound when i quickly ingauge or disengauge the clutch, when i quickly get off the gas, or get on the gas quick.

i also noticed that when im in 4th and i get down to a real low RPM like 1500 or a little lower and i, not smash on the gas but give it good gas, i hear a grinding noise until the car gets to a little more higher revs.

and where are my U-joints?

thanks

[Mike325]

The u joints are on the drive shaft. They are at the end of it, at the diff. Still need to know if it is engine speed related, or road speed related. Sounds like the u joints or center bearing so far though.

[Bimmerboy91]

im thinking is road speed related. because the only clunking i get when im at idle that is gear rattle. and like i said before, the clunking i hear when i quickly ingauge or disengauge the clutch (most of the time disengauge when the car is underload), when i quickly get off the gas, or get on the gas quick. this all happens when the car is in motion.

thanks for helping me here.

[Mike325]

When you quickly let off the gas underload, the drive train gets torqued then un torqued. Sounds like this is driveshaft related for sure. You should get under the car and look at the center bearing (you will have to take off the heat shield to do this) and also look at the u joints buy rocking the drive shaft back and forth to feel the play in the u joints.

[Bimmerboy91]

when i quickly ingauge or disengauge the clutch (most of the time disengauge when the car is underload), when i quickly get off the gas, or get on the gas quick. pretty much there it is. should the driveshaft have any play at all? i know stupid question.

and if it does have play, its the u-joints on the drives shaft?

and looking at the CSB what should i look for if its bad? actually, what are somethings i should look for when im under the car overall.

thanks again

[Mike325]

The driveshaft will have some play while you try to turn it, because of the trans and diff moving slightly. Put one hand on the drive shaft to hold it and the other to try to twist it. You should feel no play then. To check the center bearing, look around the bearing at the rubber around it. If it is cracked, then it is no good. You could also try pushing up and pulling down on the drive shaft to see if the drive shaft will move because of a failed center bearing.

This could also help you out. Look at your trans selector rod (the metal stick that goes from the bottom of your shifter to the back, top of the trans. See if there are any marks on it. I think that you may have bed motor mounts, and when your car is under loads, the engine and trans shifts up, and the flex disk is hitting the selector rod.

Does this only happen while turning?

[Bimmerboy91]

the wierd clunking when turning? no it happens all the time. but i have kind of noticed a slight, if you really pay attention, growning sound when im turning and accelerating. but it doesnt sound really bad.