linkz761

Me and my dad were having an arguement and i just wanted to make sure that I was right. Under normal driving conditions, what makes the tranny shift into the next gear? I know when yur cruising along and you punch it, the kickdown cable makes it downshift, but what makes it normal shift? thanks

sofakingdom

iTrader: (1)

The balance between the governor weights, and the modulated pressure...

As the car speeds up and the governor goes faster, it eventually overcomes the pressure, which lets it move, which tells the trans to shift up one gear. The TV cable changes that pressure; the more the cable is pulled, the higher the pressure, so the faster the governor has to be spinning for its little weights to overcome it.

Vastly oversimplified.

linkz761

So I would have to do more than just adjust the kickdown cable to get my car to shift at a different rpm during normal driving? ight now itll shift into second at like 1500 rpms if you dont give it alot of gas.

Abubaca

iTrader: (3)

You can't really "adjust" the cable to your liking. It's either right or it's not. If it's wrong, you can adjust it to make it right, but it's not really a preference thing.

It's either right or wrong.

.....and I haven't driven my Iroc in a few weeks, but under light (normal) throttle, 1500 sounds about right for a 1-2 shift. If ya wanna play a little, just shift it manually.

sofakingdom

iTrader: (1)

Exactly; you can't really "adjust" the trans behavior with the cable. The part that the cable moves has its own range of motion that it goes through, which it has to do from idle to WOT. It simply tells the trans where the gas pedal is.

To change the shifting properties of the trans, you change what the trans does with the "info" of where the cable is; that's a part of what shift kits and so forth accomplish.

linkz761

Well, I was just wondering how a tranny shop would move the shift point. I recently had this tranny rebuilt, well recently as in 9 months ago, but they said they could adjust it. I could be wrong about the rpms that it shifts at, but it seems to shift way too early. I know that adjusting the cable made it shift a bit harder, but thats about it.

sofakingdom

iTrader: (1)

The usual way of "moving" the shift point in a 700 without alot of disassembly, is by re-calibrating the governor with different springs and/or weights. You (they) can do that wth the trans in the car.

Abubaca

iTrader: (3)

The first time I put in my current 700r4, I didn't properly adjust the TV cable. The car shifted SUPER soft. After reading posts here on TGO, I realized it wasn't adjusted properly. Setting it properly made all the difference in the world. It now shifts real hard at WOT, and firm but not TOO hard at part throttle.

For casual driving, it's fine. What I've found for "performance" driving is this: From a stop, WOT will spin the tires. Feathering the gas all too often results in a early 1-2 shift. Not always, but you gotta get it right in between spinning the tires and shifting early. I put it in first gear manually. By about 4000 RPM, I'm past the point of spinning, and at WOT. I bump it into "D" right before the trans would shift on it's own to avoid me over-reving while in first. The tranny shifts itself into 2nd with a little bark, and we're off and running at WOT from there on out!