infinitebird

iTrader: (11)

Ok, I don't have much experience with transmissions but I'm having these issues.

1. On the 1-2 upshift there is a loud thud or banging that is happening, feels like it is underneath and behind me. It kind of feels like it travels down toward the rear of the car and vibrates the rear as well.

2. On the 2-1 downshift there is a bad jerking motion where the car lurches before going into gear.

The other shifts are mostly normal. Once I'm into second gear the other shifts work well at partial and full throttle.

I've already checked the basic stuff like trans mount etc. I figure it is something bad with the trans since it's only occurring in these gears.

I guess what I'm really wondering is should I just order a new built trans from a sponsor or could this be a cheaper fix at a transmission shop? I want to get a built trans eventually but if there is a cheaper fix for the stock trans I would do that for now. What I don't want to do is spend 2k at a transmission shop for them to rebuild the stock trans to stock specs.

Jays_SSZ28

iTrader: (2)

The main part that controls the 1-2 shift is the servo and it's accessed on the passenger side of the transmission case. It can usually be taken out and checked with the transmission in the car.
It's really hard to diagnose a noise without ever seeing the car.

You sure it's not the header hitting the floor? Could be a bad motor mount letting the engine twist up.

infinitebird

iTrader: (11)

I don't have headers so I don't think it's exhaust related. I checked the motor mounts and they looked good, plus I kinda doubt it's that because it does not do it on initial acceleration, only when the the shift happens. I've had a bad trans mount before and that would make noise as soon as you got moving.

performabuilt

iTrader: (25)

If you have not relocated it check the torque arm bushing and bolt the bar running from trans to rear end,