#1. Usually just when I'm on the freeway. When I apply the brake from any speed above 55 MPH the car slightly vibrates. It's not a MAJOR vibration but it is present. It's MOST present between 15% and 40% Brake, brake harder and it goes away. When I brake soft however the car has this shemmy in it and I can't tell where it's coming from. I've had this problem for awhile now. I had a bad Right Front Brake Calipre (I knew because the Rotor on that side was always loose) and replaced it and the Rotor is tight again and it did help the problem somewhat however, there's still quite a bit of vibration under moderate braking at highway speeds.

#2. I have an A4, Just before the Transmission shifts into the next gear or if the RPMS exceed 2K I feel something SERIOUSLY vibrating right under me. It really sounds like running over those Stop Sign Warning Bumps. I also feel it again but at a constant rate when doing 70 MPH or up... Is this a sign of my 10 Bolt getting ready to crap out? Or something like a transmission mount?

 

first one sounds like warped rotors, bad pads or wheel bearing issues.

second one sounds like trans mount or possibly the Ujoint

 

I don't have any floor jacks for the tranny mount, how much would that cost to fix?

Any other reliable tranny mounts out the besides Polyurthane? I had one before and it vibrated me to hell...

 

I'm with Teke for the most part. If it was a u-joint though, it would get progressively worse the faster you go. In other words, drive shaft issues are MPH dependent. If it's RPM dependent, it's most likely the mount. As for the "loose" rotor....I don't know how it could be loose unless it was severly cracked. The wheel is what holds the rotors on. Take off the caliper and wheel....the rotors should slide right off. Either way, the vibration you speak of sounds like warped rotors. I got some Baer replacement rotors and Hawk HPS Pads from TireRack and they seem to be holding up well. Better than the cheap stuff at Autozone and cheaper than the crappy stuff that came on the car...

 

just get a stock tranny mount from autozone, i agree with you on the poly mount, vibration galore

 

just this morning i got in my car to run an errand and i noticed that my car was vibrating as it shifted gears . would that be the same thing? i just changed the tranny mount no more than a month ago.

 

Exactly what I feel, especially right before it shifts from 2nd to 3rd gear...

 

anyone have any ideas ???

 

I would make sure your tranny mount is bolted up tight. I had one that backed off on my once and it started that...looked under the car and the nut was just about to fall off the mount. Or your mount could be trash..the original rubber ones can go quickly depending on how you drive. I have a poly mount and only noticed some vibration when I am 60 above on the highway.

You coudl always have your tires checked to see if they are aligned and balanced right. If they are out of alignment or balance it could cause the car to vibrate when braking also.

 

my car doesnt vibrate while braking, but the tranny mount that is on my car is from napa.....possible trash?

 

anyone????????

 

Not necessarily. My s-10 has a bad u-joint and it only vibrated between 25 and 30 mph. Other than that it was smooth all the way to 70mph. I dont go any faster than that, old girl can take much more

 

I did a search on one of the f-bod sites, & found this...http://www.f-body.com/forum/showthre...ount+vibration
Basically, not everybody gets the prob, but Suspension Dynamics (or is it Energy Dynamics) polyu mounts seem to be known for the vibrations that we are experiencing!
Hope this helps!
John

 

try stomping on the pedal. if you hear a thump on the passenger floorboard then it's the tranny mount. i had a dent from it being completely broken. replaced it and it's fine

secret: if your mirror is vibrating up/down or left/right it's a tire, i dont remember which means front and which means rear. if the mirror is vibrating in a circular motion it's the driveshaft...either out of balance or bad u-joint...