Thumping in 3/4th gear.
But I've ran into some issues shortly after replacing my Broken Tranny mount with an Energy Suspension one, I have a 1994 A4 Firebird Formula with the 3.24 Gearing and LT1 with 140k Miles. It's mostly stock except for little things like a MAF descreen, CAI, and Throttle Body.
Okay here's my issue: My acceleration is fine and the shifts are firm, but whenever I'm at about 60mph and push the Throttle in 40% or so I downshift from OD into 3rd gear, and then a deep Vibration out of hell comes from my console area, and gets worse the faster/more RPMs are on the engine. It's not a steady Vibration, but a Rhythmic THUMP THUMP THUMP THUMP that gets heavier and faster. The Thumping is about half a second in rhythm, and I feel like I'm losing power because of it. I haven't tried shifting into neutral when the thumping begins, but I will try that when it gets warmer haha
I seem to notice the thumping even more-so during WOT but only in 3rd/4th gear.. And sometimes, the Vibrations are subtle where-as most of the time they're very violent. Also, revving in Park or Neutral while not moving doesn't produce the vibration, so I don't think it could be Engine related.. I'm mostly thinking it's a Driveshaft or Tranny issue. I've had all my tires balanced and aligned, as well.
Could it be a bad pinion angle? I don't think it could be so deep and 'thumpy' to be that.
Anywho, thanks for reading! Just trying to get some clarification here
Last edited by FireBirt; Jan 10, 2015 at 09:51 PM.


