Severe Vibration!
Severe Vibration! OK I just did alot of stuff and I want to share my results with you and also ask for some opinions.
I have an 02 Trans AM....A4.....with a few bolt on goodies..its been dyno'd at 323 RWHP. I've only been able to get to 13.20 but have spun on every pass i've ever made.(more than 30 passes) I then put some new 17X11's on the rear with 315's and it still is spinning. I guess the next mod will be Drag radials. Anyhow......friday night was my last pass on stock suspension and 3.73's. Monday it got welded on tubular SFC's. This by far is the single best mod I've ever done. $113 shipped plus $40 at the muffler shop for doing the welding for me. Tuesday it got a 32mm sway bar and energy suspension bushings. NOTE: DO NOT FORGET TO USE THE ASSEMBLY PRE LUBE....the noise is unbearable...you will hate yourself. Prelube is your friend. I"M serious. Then it also got Tubular LCA's. Now up to this point the car has just become the smoothest it has ever ridden and i'm lovin life. Tuesday night......I start hearing a thumping. Then I start feeling it in the floorboard. Now the car has 35k and the last time it did this..it had about 20k. The dealer had to replace the axle bearings. So Wednesday night..i pulled the axles and to my surprise...not only the drivers axle, but the passenger axle is pitted and or split...right on the bearing surface. needless to say...the dealer never fixed the problem, just patched it. Needing to get home that night...new bearings were temporarily installed, and a new 3.23 ring and pinion. (hidden agenda) OH YEAH, I have a loudmouth, and i must officially be too old(30) b/c its starting to be too loud. Anyhow, I LOVE 3.23's and the car is even more friendly to drive. Friday.....today...I installed a UMI tunnel mounted adjustable torque arm, adjstable panhard bar, strut tower brace. I drove the car around the block several times and can say....this is the best handling car i've ever driven....i've had some good ones too. Put it this way: Point the car where you want it...and it will go there. WOW!
Heres the problem. On the way home today I decided to get on it. I obviously did not during the test drive, cuz accellerating above 65-80 the car feels as if its going to vibrate to pieces. An amzingly high pitch whine starts to overshadow the loudmouth exhaust. As soon as I let off, the vibration goes away. If I give it just enough gas to "float" the drive shaft(not torqing up or down) i can hear all kinds of noises. but its not horrible. once I get below 40 there is virtually no noise at all. If i give it gas and let off, allowing it to tq up and down...I think I can feel the drive shaft or maybe even the trans move up and down. I'm pretty sure that pinion angle is my main problem...As I eyeballed it and had nothing to go on, plus I thought -2 was in relation to the plane of the ground...now I know it is in relation to the driveshaft plane. 2ndly...i now have a more rigid solid mounted TQ arm and it is probably letting me hear more of the imperfections in the axles. Does anybody have any advice as to what they think I may have done wrong.
Also, after removing the stock TQ arm, I left both halves of the clamshell bushing still in place on the tailshaft housing and retightened all bolts up so that the exhaust hanger could still be in place. What have you guys done? Last thing: When I unbolted the tailshaft bolts for the TQ arm bushing...I noticed an Oil leaking from the holes, and from the vent tube......it was not PINK transmission fluid...it was a light brown and did not have a trans fluid or gear lube smell......any idea what that was?
I have an 02 Trans AM....A4.....with a few bolt on goodies..its been dyno'd at 323 RWHP. I've only been able to get to 13.20 but have spun on every pass i've ever made.(more than 30 passes) I then put some new 17X11's on the rear with 315's and it still is spinning. I guess the next mod will be Drag radials. Anyhow......friday night was my last pass on stock suspension and 3.73's. Monday it got welded on tubular SFC's. This by far is the single best mod I've ever done. $113 shipped plus $40 at the muffler shop for doing the welding for me. Tuesday it got a 32mm sway bar and energy suspension bushings. NOTE: DO NOT FORGET TO USE THE ASSEMBLY PRE LUBE....the noise is unbearable...you will hate yourself. Prelube is your friend. I"M serious. Then it also got Tubular LCA's. Now up to this point the car has just become the smoothest it has ever ridden and i'm lovin life. Tuesday night......I start hearing a thumping. Then I start feeling it in the floorboard. Now the car has 35k and the last time it did this..it had about 20k. The dealer had to replace the axle bearings. So Wednesday night..i pulled the axles and to my surprise...not only the drivers axle, but the passenger axle is pitted and or split...right on the bearing surface. needless to say...the dealer never fixed the problem, just patched it. Needing to get home that night...new bearings were temporarily installed, and a new 3.23 ring and pinion. (hidden agenda) OH YEAH, I have a loudmouth, and i must officially be too old(30) b/c its starting to be too loud. Anyhow, I LOVE 3.23's and the car is even more friendly to drive. Friday.....today...I installed a UMI tunnel mounted adjustable torque arm, adjstable panhard bar, strut tower brace. I drove the car around the block several times and can say....this is the best handling car i've ever driven....i've had some good ones too. Put it this way: Point the car where you want it...and it will go there. WOW!
Heres the problem. On the way home today I decided to get on it. I obviously did not during the test drive, cuz accellerating above 65-80 the car feels as if its going to vibrate to pieces. An amzingly high pitch whine starts to overshadow the loudmouth exhaust. As soon as I let off, the vibration goes away. If I give it just enough gas to "float" the drive shaft(not torqing up or down) i can hear all kinds of noises. but its not horrible. once I get below 40 there is virtually no noise at all. If i give it gas and let off, allowing it to tq up and down...I think I can feel the drive shaft or maybe even the trans move up and down. I'm pretty sure that pinion angle is my main problem...As I eyeballed it and had nothing to go on, plus I thought -2 was in relation to the plane of the ground...now I know it is in relation to the driveshaft plane. 2ndly...i now have a more rigid solid mounted TQ arm and it is probably letting me hear more of the imperfections in the axles. Does anybody have any advice as to what they think I may have done wrong.
Also, after removing the stock TQ arm, I left both halves of the clamshell bushing still in place on the tailshaft housing and retightened all bolts up so that the exhaust hanger could still be in place. What have you guys done? Last thing: When I unbolted the tailshaft bolts for the TQ arm bushing...I noticed an Oil leaking from the holes, and from the vent tube......it was not PINK transmission fluid...it was a light brown and did not have a trans fluid or gear lube smell......any idea what that was?
Last edited by 1BADBLACKBIRD; Nov 11, 2005 at 10:43 PM.
I won't speculate much but will share what I know for sure. Doesn't sound like tires since it's throttle-affected.
Your TA is definitely a factor. It may or may not be the whole problem, but will definitely transmit more noise to the cabin.
I'm thinking that your suspicion of pinion angle being your culprit is sound.
Good luck.
Your TA is definitely a factor. It may or may not be the whole problem, but will definitely transmit more noise to the cabin.
I'm thinking that your suspicion of pinion angle being your culprit is sound.
Good luck.
