Can someone explain how the lockout works? Also under mild accelaration,my 700r4 shift hard from 1st to 2nd, also 2nd to 3rd. Sometimes it clunks so hard, it shakes the whole truck.

Hard shifts with a 700R4 are normally an indication the TV cable is not properly adjusted. Do a search on the site as I know the question and proper adjustment procedure has come up in the past.

When you say "lockout" are you referring to the shifter, or the transmission?

I was told the "lockout" means the torque converter locks-up in 4th gear allowing the trans to stays in overdirve.

I was told the "lockout" means the torque converter locks-up in 4th gear allowing the trans to stays in overdirve.

That's one of the designed in features of the 700 R4. It's a great fuel saving feature and is controlled by a 12 volt fused supply wire. When the trans is in 4th and it's energized, it locks the converter up. When it's not, the converter unlocks and slips a little. Usually the engage/disengage is barely noticeable. To test it, drive the car about 50 mph, level ground and in high (4th) gear. Then put a little pressure on the brake pedal, but not enough to actually slow the car down. You should hear/feel a noticeable difference in engine noise/RPMs. If it doesn't do anything at all, check the wiring to the TCC (There's a wire and connection on the side of the trans that finds its way back to the computer somehow).

None of this relates to the problem you 1st posted though (clunky and hard shifts between 1st, 2nd and 3rd gears). I'm with oldelky80 on this one. I'd bet your TV cable is unhooked or out of adjustment. If you aren't sure about this and how to remedy it, check out www.bowtieoverdrives.com then "TV System" link on left for some detailed instructions.

If it isn't the TV adjustment, then it may be something more serious wrong in the trans or converter. In that case, a trip to the experts may be in order.


Good luck. Let us know what you find.