What are the essential upgrades to any 700R4 that would make it shift smoother and perform better under normal operating conditions. Not asking a race set up, just something that is available when you "need" it.

Been searching around a bit and it seems it is:

1. Corvette Servo
2. TCI 700R4 Constant Pressure Valve Body
3. Throttle Valve Plunger & Sleeve
4. Shift Kit of some sort
5. some sort of stall converter

Does this sound about right? Or is there some over kill here?

 

Get a modified shift kit from Dana at ProBuilt Automatics. He can also include the servo. If you're going into the transmission at all, upgrade the 3-4 clutch pack at a minimum. I don't think I'd bother with a converter unless you're changing engines and\or camshafts. Check with Dana though. He may recommend something to go with the shift kit.

 

Thanks, I'm eventually going to be sporting some SLP shorties, Runners, Airbox along with Edlebrock Intake and Heads Unknown at this point along with 3.45 rear end which may warrant an engine pull and converter change.

Not certain what a 3-4 clutch pack is, is that along the same lines as the TCI 700R4 Constant Pressure Valve Body?

 

They're internal clutches inside the transmission. The 3-4 clutch pack is usually the first thing to go in these. The diagram below might help explain it better.

 

I wouldn't do any of that (except the Corvette servo) unless I was gonna get a full rebuild.
I have a 700R that was working when I pulled it from the donor car. I put in a new filter, TCC solenoid, front pump seal, and Corvette servo. I also got a new 1800-2000 stall torque converter from Monster transmission. That's all I'm gonna do until I do a full rebuild, or get a whole new transmission...

 

Smoother shifting and a constant pressure valve body are at the extreme opposite ends of the spectrum.

The recommendation of the modified Trans Go kit from Dana is a good choice. 99.9% of the kit can be installed without dropping the transmission.

RBob.

 

Are you saying constant pressure valve body produces harsh shifting?

 

Yes, it maintains high line pressure all of the time.

RBob.

 

Any reason in particular? I understand hesitating on the 3-4 clutches since you essentially need to dismantle the entire transmission, but the shift kit only modifies the valve body - you only need to drop the pan to get to that. Dana's shift kits are about the best bang for your buck you can get for transmission performance.

 

Not saying a shift kit is a bad idea, if that's what you really want. I just think a person needs to draw a line somewhere when it comes to modding an old transmission without just rebuilding the entire thing...

 

As long as the transmission is still in good working order, the right Shift Kit can help extend the life of the transmission. A Shift Kit will not save a bad setup. If you have someone you dislike a lot, give him the "constant pressure valve body". To harsh a part throttle shift, soft WOT shifts, and they are very hard on the pump.

 

Maybe I should have stated the question a different way. I'm looking for a way to make the transmission civilized, but perform. I know that it is an old design, and this may not be possible, but when I compare it to my ZF 6HP its barbaric. The ZF 6HP can give me a luxury ride, or snappy shifting with no lag all the way thru the torque band. My 700R4 does have a shift kit, when i step on it I feel like there is some lag and it doesn't come alive until it slams into 2nd gear. Just some simple kicked back city driving, and the transmission seems ok, but it could be better. The trans has 64K miles on it, pretty sure it is fine, just an old design that needs some modernization to get it up to par with 6 speed, computer controlled automatic. Does this make sense? I feel like the 700R4 provides the same shifting smoothness as older, early 70's design, just has an overdrive.

I don't want a drag strip transmission, I want a sports car transmission.

 

Yes, this can be done. What year is the transmission? This will determine which of the kits to use here. Then what gear ratio in the rear end? I need to know pretty much everything about your motor, what is done to it, type of intake manifold, type of carburetor, the vehicle this is in, how you drive, etc. I can help with the torque converter, once I know about the motor and the camshaft specs at .050" lift, and LSA of the camshaft.

 

Good to hear. I'm not there yet, but will have SLP shorties and full SLP exhaust all the back /runners/airbox along with Edlebrock Intake and Heads Unknown at this point along with 3.42 rear end. Cam is 90 305 TPI cam which is

.413 intake lift / .428 exhaust lift / 202 intake duration / 207 exhaust duration / 114.5 lobe (but may need to change out that cam to get the desired peak torque/hp goal with trade-off being a very street-able car, not daily driver, but something that has some omph to it on occasion. usually just pleasure driving, definitely not a drag strip car.

 

Hey, Liquid, wanted to know if you have done anything with your transmission yet. After reading your post, I have the same questions. My Formula only has a little less than 20,000 miles, and it seems to function fine, just not very "performance" oriented. Car was originally a LO3 TBI 305/auto/2.73 non-posi that is now L31 350/TPI/auto/3.23 posi and I think the tranny is letting it down. At the very least it needs the governor re-calibrated (it shifts out of first too quick and won't stay in first with anything short of WOT, which then just spins the tires) plus WOT shifts are too early (1-2 at ~4,200 and 2-3 at ~3,800).

 

Never did anything about it. I sort of on the fence about doing anything to the car. Its a bit of a time capsule. I would be tackling the tranny last. Was just planning ahead. I can tell you that I do have a shift kit in it, which seems to work pretty good, nice snappy shift out of 2nd gear. In fact, maybe too snappy, and I get nervous and think it isn't gonna shift and then bammm! I'm just comparing it to a modern day german ZF transmission with 6 gears, and that is when it becomes a let down. (The ZF shifts so fast and smooth, no big drop in RPMs and torque curve just keeps climbing) Maybe your ECM needs tuned to a 350 for that red line shift, which I think is higher on a 350 than a 305. (not sure ECM has any involvement) I am working my way from drum brakes posi 2.73 to 3.4X posi with factory disks of the period. That is step one, that I will probably take. just got side-tracked with other car, it needed some suspension tuning, and one thing led to another and rebuilt the entire suspension. man its nice! Once I track down a leak by the engine I will get back to the Bird !

 

P.S. If you haven't stumbled across it already, look into Corvette Servo. Sounds like its an easy upgrade that a lot of people are happy with. Have no idea what it doesn.

 

Thanks for the reply. ECM has no control other than torque converter lock-up; shifts are controlled, among other things, by the governor. I'm looking in to Dana's "Shift Kit" as a possible upgrade. Not sure whether this "kit" can be installed with the tranny still in the car or not.

 

keep us posted.