I hope there's someone that's had a similar problem with their 700R4 and can point me in the right direction.

72 Chevy 2wd, TBI 350. The lockup circuit is an aftermarket wiring deal, which goes to the brake switch and also an optional toggle for manual lockup. Transmission worked behind the old 305 fine for a few years, then I yanked the tranny for a rebuild and a new engine. Now it works good, except it shifts too early. I've adjusted the TV cable to specs, so that it's at full pull at WOT. The bracketry is all stock, so the geometry is fine. There's one other problem. When I manually shift it into 2nd or 3rd, possibly first, the converter is locked (or feels like it). As I roll to a stop, you can feel it downshifting hard.

I don't know if there's a pressure switch malfunctioning or what, but I was hoping someone here could point me in the right direction.

The only topic I can find online that is similar is found here:

http://www.chevelles.com/forums/showthread.php?t=215538

Your governor pressure is higher than your throttle valve pressure. If the TV cable is not adjusted to where your line pressure is correct for given throttle angle the governor pressure will overcome the shift valve and and earlier than desired shift point will occur. Over time low throttle valve pressure will cause low line pressure and cause clutch pack slippage.....blah blah blah...ect ect ect.

Fine tune your TV cable adjustment until you have reached your desired shift points. Sounds like your brackets are a little ascew. The WOT adjustment only works 95% of the time from my experience.

I don't adjust with the Tv cable, i adjust with governor weights and springs.
I get the kit from summit for like 30 bucks.

For fine tuning shift points when your line pressure is good/to spec and TV cable adjusted properly (TV adjustment will affect line pressure), adjusting governor wieghts is a good modification. Similiar to an adjustable vacuum modulator.

The brackets are all stock, and if I adjust it tighter, I won't be able to hit WOT. Also, the governor is the same one, and it shifted correctly before rebuilding. The only thing changed other than new clutches, etc... is that I added a corvette servo and stiffer accumulator springs. If you think the governor will fix it correctly, I'll give it a shot.

The only weirdness is the lockup when manually shifting. Anyone have an idea why it might do that? I was driving slowly down my dirt road last night, and it just about killed the engine as I slowed down before it downshifted hard.

Thanks guys.

I'm not a tranny tech but I've messed with shift kits and govenpr spings etc over the years--I'm guessing the govenor is the wrong one for the application so you need a shift point kit from B&M or someone similar and adjust to your needs.

Jason :)

just an FYI, I had the same problem, took it in to someone who knew what to do to adjust it and it was obviously too late as I now am swapping to a th400.

First thing I see is that stiffer springs are going to cause firmer shifts , that why you do that mod.

With your lock up problem ; try simply unplugging the 4 wire connector and driving it ,if you completely disable the lock up soleniod and then have a problem ,then you know that it is between the lock up sol. and the convertor and not electrical (in as much as energizing/de-energizing ),it would be a bad sol,convertor or plumbing .

You can drive it unlimited distance as long as you don't use overdrive,so testing the wiring is not going to harm anything .

The wiring inside from the upshift pressure switches that are on the end of the valve body have varied over the past 15 years of manufacture and may have been hooked up incorrectly for the aftermarket lock up controller .I make my own lockup system and I don't use any of the internal components,my point is ,find out if it is mechanical or electical and trace your wiring for you controller if it's an electrcal problem.

Well, I think I got everything figured out. As for the lockup, I believe I mistook the engine braking in 3, 2 and 1 to be the lockup working incorrectly. After researching, I realized that while having the selector in those gears, the overrun clutch applies, which gives that engine braking. While in OD, that clutch isn't applied, and thus no engine braking. There's more info on that here:

http://sethirdgen.org/tranny.htm

As for the early shifts, I had set the TV cable to full pull at WOT. I did this as mentioned in most places, which says to manually move the throttle at the throttle body. I noticed a few places said if that made it shift too early, to actually have someone hold the throttle down in sitting in the drivers seat, and then adjust the TV cable to full pull. I did this and it shifts perfect now.

I think everything is dialed in perfect now - thanks for all your replies!