Question : Transmission swap issue

[Joelfke]

I recently swapped my transmission with a junkyard trans (im not expecting the world here) but everything seemed to be ok until i felt it shift quite harshly. I got DTC P0730 incorrect gear ratio. According to the charts ive looked up from fellow members(http://www.gmtuners.com/transmission/2004_4T65-E.pdf) it should be the same as the one i took out.

My original trans is 4RDB and the junkyard one is 4LDB

I am certain I plugged in everything and connected all grounds. Anyone else encounter this?

[95Grand-Am]

Are you sure, the chart shows one is out of a w-body with a 3400 the other is out of a w body with a 3800, i was under the impression that they don't share the same bolt pattern.

[bszopi]

Yes, both the 3400 and 3800 share the same bolt pattern. That's one reason people always like to suggest 3800SC swaps (not here of course), because they bolt right up.