4R70W Problem?

When I floor it, it doesnt shift down. Could this be to a messed up TV Cable, or a bad torque converter? (I'm pretty sure it has a bad TC...from the massive vibrations i get), but I wasnt sure that a TC would affect the downshifting problems..

The 4R70W is an electronically controlled trans so doesn't have a throttle valve or throttle valve cable.

Go to www.tccoa.com, their tech articles, trans section, read thru the first article "trans 101" and look for the info on the valve body solenoids.

I would suspect that's where your problem lies.

Downshifts are only commanded when the EEC sees high load. Load is based on the MAF sensor signal (airflow) and throttle position. Of these two, the MAF is the "god" sensor.

Do you have a K&N installed? I'll bet so. Get yourself a "tamper-proof" Torx #20 bit, remove the electrical connector from the MAF sensor, remove the two Torx screws, and CAREFULLY pull the sensor out of the MAF housing. Look at the TWO very small sensor wires, if either is broken, the MAF is junk. CLean them with some brake-clean of similar NON RESIDUE cleaner, and reassemble when dry.

As far as your converter goes have you tried draining all your tranny fluid. I had the same problem in my 94. I ordered a new converter from hughes and they sent me the wrong one even though they said it was up to spec, But thata a long story. Anyway I pulled the drain on the old converter while it was in the car, dropped the trans pan, changed the filter and filled her back up and the converter issue is gone. Shifts like new again. Could also be a shift solenoid.