I have a 700R4 in my '86 IROC, and I have a few questions regarding the shifting of the tranny.

1. Obviously, I can manually shift the transmission... but is this really faster than just leaving in Drive?

2. What are the little "internal shifts" that I feel without manually shifting?

3. On a lot of the posts guys talk about their car "shifting" at a certain RPM... are they usually referring to the "internal shifts" or the car physically not shifting after they've manually shifted into a higher gear?

4. Whenever I'm at WOT in Drive (third gear), the RPMs keep climbing until I let my foot off the pedal a little, it shifts, then I slam it down again. Why doesn't the tranny "internally shift" in this case?

Answers to any of the questions is greatly appreciated. I know the questions are pretty basic, but I'm slowly learning this transmission stuff.

 

A stock 700R-4 trans will not shift into overdrive (4th) under WOT conditions. It would have to be modified to have this happen. Some cars when left in "D" will shift at the optimum point, some won't. The ones that won't will be faster shifting manually. 700R4s shift under part throttle like this: 1-2, 2-3, converter lockup (feels like a shift), 3-4. The converter will lock & unlock as load increases or decreased, When driving at or around 45mph the trans will shift in and out of overdrive (4th). With most 700's you can hold the shift by leaving it in the lower ranges, when left in drive the shifts will be controlled by the governor inside the trans.

 

So, basically, there are four "internal" shifts that the tranny does by itself that parallel the four manual gears on the automatic transmission? If the car shifts from, say, 1-2 "internally" while in D, is that essentially the same as if I were to shift from first gear to second gear manually? (but the difference is that the transmission is doing it automatically, whereas I'm shifting based upon the RPM I want to move to the next gear - I just have to figure out which way is the fastest for my 700R4?)

If what I just said was correct, does that mean that there are no "internal" shifts whenever the shifter is physically in the lower gears?

 

Personally i think shifting manually is more efficient. First off you can cruise at any RPM range, which is good for racing from a moving position, which is much better for your tranny than downshifting at high speeds unless you have a good shift kit. Second the trans won't shift on you at like 3000 RPM's at WOT, and if you push it too far there is about a 5800 safety on it, and the shift will occur automatically even if you're holding it in first, second, or whatever. Third just as if you keep your car in D insead of overdrive you get more torque, if you keep it in 2 instead of D, you get more torque.

 

It completely depends on your car. Before I installed headers, my car was fastest by leaving the shifter in 'D.' Since I installed the headers, and my car now breaths better in the upper RPMs, my car is faster by manually shifting. The reason for this is, with the shifter in 'D' and letting it shift on its own, it will shift at about 4700. With the headers, and more upper RPM power, my car is faster by manually shifting at 5250... an RPM I would never see with the tranny shifting itself.

 

I usually just left mine in overdrive, even when racing. the only time I would manually shift it was when I pulled up next to ricers going about 45 or 50 and pop it into second and tap the gas for a jump. Hehe 9 times out of 10 that scares them away because the front end looks like its gonna pull off teh ground when I do that. although my 700R4 blew up after 20,000 miles, so take what u want from this...

 

Try this - instead of leaving the light in OD, try leaving the light in 3rd. I get much firmer shifts, at least it works with my 4L60E.


Ron

 

It's probably not the best to manually shift all the time, since line pressure will be greater. The internal shifts are the automatic part of the tranny automatically shifting for you.
Sounds to me like your TV cable isn't properly adjusted, do a search for transfixleo's method.

 

Yeah, usually I have been leaving it in third (D) just for simplicity... I don't have actual times with shifting manually versus letting it shift itself.

I got my new cap and wires yesterday so I was testing out the car... usually when I shift manually at WOT, I let off the pedal a bit and shift then floor it again. This time, I shifted to second around 4500 without letting off, but it didn't shift... to avoid redlining it too much I let off. Is there a timeframe or "gap" before the tranny actually shifts after I move the shifter to second? I've heard about cars not shifting when at WOT, but I thought that only occurred when going into OD.

EDIT: Per Mark's message, I had already adjusted the TV cable prior to taking my car out that day.

 

Whatever position you leave it in (1,2,D,OD) will be the highest gear that it will automatically shift into. I think that's what you asked a few posts back.

 

So, if I leave it in D then it'll automatically shift through first, second, and then stop at third? This raises another question... if I were letting the transmission shift itself, would it be best to have it in D or OD when drag racing? Around town, I drive in D just because there's more power available "sooner" than with OD... but once I get on the highway I shift into OD.

 

Actually around town, it's best to put it in D if the car might be going in and out of OD due to slow speeds, this allows for longer life of a part, but I forget the part name.
Oh, manually shifting, I would be very careful I wiped the cam in my 305 manually shifting, went to shift to D and slid into N at WOT, that's why I have this. An aftermarket shifter will be very useful and safer.

 

Alright. I already invested in the same shifter you have, so I shouldn't have any problems with going through a gear accidentally, etc. I just had my car out again, trying to figure out the various speeds that it shifts while in D and OD. I readjusted the TV cable again before I left just to make sure everything was OK. It seems like the 1-2 shift is about 10 mph, the 2-3 shift is about 25-30 mph, the torque converter lock/unlock is around 45 mph, and the 3-4 shift is around 50-55 mph. If I were shifting manually, would I have to wait until I reached these approximate speeds until the car would shift once I moved the shifter? The reason I ask is that I shifted from first to second at about 20 mph and the tranny didn't seem like it shifted at all.

Also, is there an easy way to tell exactly when the transmission shifts automatically, without relying on "feeling" it? (I've noticed that my RPMs dont change much when it shifts)

I really appreciate all of the informative help that I'm receiving about this topic. Thanks guys .

 

When the car shifts, the rpms will drop, how much depends on your speed. With the tranny shifting at a certain speed automatically that may not be a bad rpm 10mph for 1-2 but not at WOT you'd want that to be higher.
I know on my car, my governor is out of whack and leaving it in D it shifts @ 2500rpms @WOT so I just manually shift when I want to go faster.

 

Hey, when it says "press the D button and pull the cable casing (the black tube) back as hard as you can and release the button" does that mean pull it back towards the firewall or towards you at the front of the car?

 

Towars the back. Then get in with the car off and gently floor the gas pedal. You will hear it click into place.

 

back towards the firewall

 

Oh, you release the D button and then floor the gas, no wonder I never got it right, I think I floored it with the D button still in. But I got someone else to do it correctly for me.

 

I really appreciate everyone's help on this topic -- thanks again!

There are still three more questions that haven't been answered yet, so I'll just retype them here to make it clear which ones they are:

#1:
If I have my car in D (3rd gear) and (let's say) that the governor's WOT shift point is 4500rpm, will the tranny go to 4500rpm for the 1-2 shift and then back up to 4500rpm again for the 2-3 shift? The reason I ask is that I've tried that on my car but the engine just keeps winding without any shifting taking place. Now, if I let off the throttle it shifts (to what gear I don't know). A tranny guy who I know said that the governor's WOT RPM setting could be as high as 6800rpm -- though I would never want to try that.

#2:
If the 2-3 shift takes place at 25mph while in D, do I have to exceed that speed when shifting manually from second to third for the shift to take place?

#3:
When I make the 1-2 manual shift at WOT, the engine keeps revving -- I tried shifting at 3000rpm and it kept going until I let off at 4500rpm. I thought that people only have problems shifting into OD while at WOT. That same tranny guy I talked to suggested that a shift kit would remove this "limitation" from my transmission, and that GM police Camaro part would remove the OD-at-WOT limitation.

 

Ward.... HAHAHAHA!

You shouldn't race the 1/4 in 'OD.' In '1,' '2,' and I think 'D,' the tranny line pressure is greater becuase the tranny is anticipating a hard, high torque output, high RPM shift.

 

I'll try my best.
1) The governor should have a set rpm to shift at in accordance to your TV cable setting I would think. I'm sure some governors do allow 6800rpm shifts, but I wouldn't think that would be on our cars, but who knows maybe with an incorrect TV cable setting that may occur.
With the tranny winding out on you on the WOT shifts, that's probably slippage meaning a rebuild might be in order.
I know my 1-2 shift is bad @WOT say I shift at 5000 rpms it will literally take a second before it goes into 2nd, so usually I'll let off the gas for it to be firmer. I've actually shaved off .2 this way according to the G-Tech.

2) If the tranny shifts into 3rd at 25mph in D, but when you manually shift you can shift anytime you want, but be careful not to over rev (obviously) and shift right when the car feels like it's losing power.

3) Yes, the police camaro part will help with the WOT to OD, the local GM dealer should carry it. As far as the 1-2 shift at 3k and continuing to rev, sounds like more slippage by the tranny.

I hoped I've helped so, I'm not an expert but since no one else has replied I figured I'd try.

You might want to try PMing transfixleo if you don't get answers that help you out.

 

Yep.

 

1. Something isn't right with the tranny. It should shift on it's own. Look at it this way, what ever gear the shifter shows is the highest gear it will allow the tranny to automatically shift into. You should not have to let up for it to shift automatically.

2. yes, you must be above the usual speed for the automatic shift. Like I said above, it's not really manual shift because all it does is tell the tranny highest gear it is allowed to shift into. If I shift into third going 5mph, it's not going to shift into 3rd gear--it will automatically shift 1-2 and 2-3.

3. At WOT at 3000 rpm you shifted into 2nd gear. That tells the tranny that the maximum gear you want is 2nd gear and it will automatically shift at the correct rpm(if it's working correctly), that may be more than 4500rpm.


When you 'manual' shift, it merely locks out any gears higher than the selected gear--for the most part anyway. Not to add to the confusion, but if you hold it in, lets say, 1st gear. If you rev it high enough it will shift into 2nd gear without moving the shifter--over 6500rpm somewhere.

 

Thanks Mark and 82camaro, both of you have really cleared stuff up for me. It turns out that the tranny guy that I was talking to is the transmission specialist for a certain pro stock drag racer... his nephew has a shop about an hour away from my place, so I'll probably take my tranny there to get it looked over and rebuilt. He said that I'm lucky that my "first-generation 700R4" lasted to 68,000 miles.

Again, I really appreciate the help. Thanks!