To start off, this is an 86 model transmission that was rebuilt about 7k miles ago with a Pro Built street/strip rebuild kit.

I drove the car Thursday and Friday and it acted like it has since the rebuild. I started the car up today, pulled to the top of the driveway then noticed something different. When I pulled out onto the highway it felt like it suddenly made the 2-3 shift and felt like it was lugging in 3rd gear. I eased up on it (long downhill from there) and it was driving fine but that had made me uneasy. I found the the first turnaround and stopped. Trans downshifted normally. I started back towards the house and the 1-2 shift felt softer then normal but at about the same point. But the 2-3 shift was early.

My first thought was TV cable. So I checked it. It hasn't changed. At WOT it is still at full travel. Nothing changed on it. So I checked the fluid level. Havent noticed any leaks, but it was about a pint low. Topped it off and went for a short drive. Started off fine, Pulled out in first gear, hit second, went to third, felt almost like normal. Then I turned around. Trans downshifted fine. 1-2 shift was close to normal, but 2-3 felt different. Instead of the normal bang-shift at the same time, it felt like shift, bang. I know that may sound odd, but that's how it felt. Then it was in 3rd gear and didn't want to downshift until I was almost at a full stop. Once at a full stop, I punched it in first, it smoked the tires, hit second still smoking them, then I let off and stopped. Then I start to park it and at less then 10 mph it shifts to 3rd and lugs. I stop and it downshifts back to first. Then I park it.

Im completely lost right now. Any insight? TV cable is good. Fluid level is good. Maybe something broke or stuck in the valve body? I don't see how anything could have happened to the shifter, but I wont rule that out, maybe the adjustment somehow changed? Im completely lost and any help would be appreciated.

What really gets me is that I drove it the last 2 days and it drove as it always has. Then today as soon as I pull out of the driveway something acts different.

 

Debating on driving it a short distance by shifting manually to see what happens. Not really sure what that will show though. Im blind on this one. Just going with it.

 

Where is the delete button? Im an idiot. Had a failure in my lockup circuit and the torque converter was staying locked except for when the brake was applied. So what I thought was 3rd gear was actually 2nd gear from about 5 mph with the converter locked. I thought it felt like a straight drive...........

 

Give me a call later today and lets see what is going on here. Dana

 

Thanks Dana, but I determined it was an issue in the lockup circuit. Mainly some dummy that accidently mispositioned a switch.