Hot Rods 700R4 - no downshift. TV cable issue?

My 700R4 has developed an issue. It upshifts fine from 1st to 4th, but it won't downshift when I give it gas while driving. If I hit the gas while driving, the engine bogs down, struggles, backfires... No downshift.

If I use the brakes and come to a stop, it is back in 1st gear. Upon acceleration, it goes up through the gears fine again.

From what I have read, this seems to point to a TV issue. It was working OK before. Phoenix transmission, installed by Bruce's Rod Shop. First one I bought broke, so Bruce's got me another under warranty and installed it. It worked OK for a while, now this...

Any thoughts/guesses?

Truck is for sale - really need to get this fixed ASAP.

 

The procedure for adjusting the cable is:
The cable should be fully extended at wide open throttle.

 

Careful, a TV cable for a 700 in not like adjusting a th350 or th400. They are highly critical to adjustment or you will cook it fast. Lot of info on the web too.

 

A pressure gauge installed in the port on the drivers side of the body will tell you whats going on....google it

 

Bowtie over drives give excellent details on setting up a TV cable amongst other things. They
Won't warranty anything unless you follow the pressure checks.

 

have a local trans shop set it up by the pressure gauge if your not comfortable doing it off the internet youll cook it fast if it aint right.

 

Throttle valve in valve body may be stuck or the Modulated throttle valve (MTV) down may be stuck. The throttle valve can sometimes be unstuck by giving the cable a few sharp jerks by hand which will fully bottom out valve, and can clean bore of debris or any minor wear ridges that can develop over time.

 

Take it back to Bruce's for them to make it right.

 

I dropped the pan on mine to make sure the valve was closing all the way on WOT. The horror stories had me nervous.

 

Also make sure the lock up disengages properly, I run mine through brake lamp switch. As stated TV needs to be set at WOT and you need the correct carb bracket to maintain correct OEM geometry for everything to work properly with a 700R.

 

Problem solved. Not transmission related. Timing was off. Carb needed adjustment. One bad plug wire. All good now. Thanks.

 

Good job always good to start with the basics.

 

Sooooo These completely non-related adjustments corrected the "no down shift" condition?