Just installed a 46re in my 94 dakota. I pulled it from a 1994 ram 1500 from my local pick and pull. The tranny ran perfect for about a week and now it sucks. When in overdrive it will randomly start to whine then starts to drag really hard. It drags for a little bit and starts jerking violently then just stop jerking ot just keeps jerking. I made it home by turning off overdrive with the button on my dash. Runs fine with it off. Got home and checked the fluid in neutral and it's full. Please help.

 

Sounds like the O/D unit is getting ready to grenade itself. Talk to the folks you got the trans from, explain the problem to them, and see if they will swap with you.

 

being a 94 it isn't a 46 RE but a 46 RH. RE is electronic governor controlled by computer. RH is hydraulic governor controlled by hyd. pressure within transmission. not terribly different within/ but there are some differences in them.
not saying the governor circuit has anything to do with what you have going on (most likely not) but the RE came out from 96 on when they came out with OBD II computer system. and no you can't swap an RE series in place of an RH unless you also swap the whole wiring harness and computer.

 

The REs came out as early as 93/94. I know I've seen an A500 42re on a 94. There are threads all over with people owning 94 and 95 ram 1500s with a 46RE. I wouldn't rule it out completely being an RE.