Originally Posted by 84x4Bronco
This how you treat all your newcomers?
Welcome sir. No, it's not how we treat all newcomers. It's just how Chinook treats everyone. We're glad to have you along and you'll likely find help here.
I'm racking my brain on what my exact issue was when I did this on a 98 with an early 4r100 but I do know that to get the tranny to shift right I chiseled off 2/3 of the teeth on the tone ring. John at Agile explained to me how they figured this out and it worked.
My project was a 2wd van converted to 4wd and necessary to put a new output shaft and tail housing on, then there was an electronic issue with the speed sensor from the new tail housing not playing well with the original 2wd ECU.
I'm pretty sure that's exactly what you're describing. I do not know anything about a ZF parking brake or how it might come in to play. My van was a V10 gas.
Hopefully MGmetalworks will speak up.
Have you called or do you know of John from Agile Offroad? That is who had my solution but this was years ago.