I had a local shop install a remanufactured automatic transmission in my 94 Z28. I had a buddy replace the transmission mount before the new tranny was put in (turned out the problem was more than the mount). After getting the car back with the new tranny installed, the car is vibrating like crazy when I step on the gas (bigger vibrations under harder acceleration). I don't think this is normal. Could the mount be causing this or something with the new tranny?

 

is it a stock, or poly mount? If it is a poly mount I think thats the problem. They are known to vibrate alot on the a4's

 

After driving the car a little more, it seems that the engine is running rough in general (in neutral and in park too). Any additional thoughts?

 

Have you changed plugs/wires lately? It could be missing and thats why it runs rough, that may also cause some vibration. Somebody please chime in if you see something else, but I would say look at the wires and plugs, one could have burnt up. Hope that helps.

 

They are saying that I need a new Ignition Coil now too. This is causing the vibrations because the engine is running really rough. If this is true, I hope my transmission really did need replacing. I think it did because this vibration is totally different when compared to the other symptoms that involved the tranny. Those symptoms were: no engine braking, not shifting at WOT, wheel hop when starting from a stop and during the shift at WOT, etc.

 

Did the vibration start after you put in the new transmission? If it did, does the vibration happen when you rev the engine in neutral? Is it speed related? I Need more information?

 

possibly the torque converter?

 

Before the new transmission was put in, the car had delayed shifts and wheel hop at WOT. It seemed to not have any engine braking when downshifting the automatic. The car wanted to lurch forward when trying to stop at a light (had to press the brake harder than normal). The car also had a loud knocking sound when shifting at WOT. This was fixed when my buddy put in a new tranny mount. The car did not run rough at all before the new tranny was put in. After the new tranny was installed, the shifting seems to be as good as new now (along with the engine braking) but the car is running really rough. The mechanic took a test drive with me and then looked at the car. He showed me the ignition coil and wire were all corroded and that is the cause of the vibrations and engine running the way it is. What are the chances that I had both tranny problems and coil problems at the same time? Could the coil have been the problem all along and not the tranny? The weird thing is that if indeed the coil is making the car run rough, the symptoms did not show themselves until after the new tranny was put in.

 

You still needed a transmission because of the no-braking action. The rough running?,coincidence? Fix the electrical problems & see what happens.

 

The shop gave me a loaner car while they investigate it tomorrow. I think they screwed something up while putting in the tranny or it is just coincidence that the ignition coil or whatever electrical problem now exists.

 

I wonder if you have fixed or found the problem yet, I'm having thesame problem,, vibration wise. thanks