I LOVE THAT SWITCH

I have a problem that the trans hits 4th at too low RPM and I have to keep it in 3rd and then throw it in "D" when I get the proper RPM. Before, I had the problem with it NOT hitting 4th at WOT. That was just after the rebuild.

I never really messed with it too much. I let off the gas and it shifted a second or two later. Not good AT ALL for drag racing. I put C6 rims on it and that made 3rd just about perfect.

I would suggest the tires, but since you are worried about it not going into 4th, I would get the throttle body sleeve. I'm not sure if this will work, but there is also a kit that replaces the electronic throttle position sensor on the trottle body and makes 75% throttle turn into 100%. This is seperate from the kick down cable, so maybe it will allow the car to shift. Just keep the pedal at about 75%, the motor will kick out 100%, and the trans will think it's at 75%, possibly making it think it can shift. I'm not an expert on that kit, maybe someone else has installed it...

 

Two things.
Your TV cable was not and is not adjusted correctly. This will cause it NOT to shift into 4th, due to lack of pressure. It is a critical step in ensuring 700R4's live after a rebuild. Once that valve body is off, you need to readjust it. Research it or PM PETEK. It can burn your transmission up very quickly.
With 3.73 gears and my 700R4, I run 119mph in 3rd at 6000 rpm approximately.
Your car is not adjusted correctly on the TV cabe.
Second: The one item Corvettes have is the Corvette Servo which allows Corvettes to go into WOT in 4th. During a rebuild, some people change them out. You got to ask the builder what he did.
I just had mine rebuilt. Dana at ProBuilt can assist to.
http://www.tvmadeez.com/article/index.php

 

His trans would have lost the 3rd & 4 th gear a long time ago if the TV- throttle valve was not adjusted correctly.

That Corvette Servo you are talking about is for applying the 2-4 band in 2nd gear mode.
You feel it every time in 700R4 or 4L60E C4 Corvette transmission shifting the 1-2 gear.
Its what helps you get that great big smile every single time you mash the gas from the stop light.
You Really notice it in the TPI cars because of the tremendous Low End & Midrange torque they make stock or lightly modded up.

4th gear servo is nothing "C4 Corvette special"
Its for apply the 2-4 band in 4th gear overdrive mode.
And you hardly feel it in a stock C4 trans being applied at WOT.
The outer 4th gear servo is shared with a C4's & non -C4'S CARS & TRUCKS 700r4'S & 4l60e'S.

I used an aftermarket 4th gear SONNAX SUPER HOLD SERVO ASSEMBLY in 87 Vert 700R4 Rebuild.
AT WOT it has a definite 3-4 shift feel like a 1-2 shift @ WOT in a C4 Corvette.

And that SONNAX Super Hold 4th gear servo works awesome.
The 3-4 shift & 114mph WOT keeps me smiling large.

Brian

 

Bria, with all due respect, i am not going to argue. I have been through 4 different 700R4's and the TV cable can be easily run for a long time out of adjustment. Most of the time it is adjusted to hit hard, which is the best of the two ways to go, if it is going to be out of adjustment. If it is adjusted the other way, it will kill it. More than likely it is adjusted where it is hitting hard.
The servo, well, get ahold of PETEK
The OP needs to go back to his builder and try PETEK.

 

Maybe,

He went back to his trans builder.

He we will report back sooner or later.

There are 1,000,000 misconceptions about 700R4 & 4L60E trannies.

They are a really very decent & tough trans when rebuilt correct.

BR

 

If I am not mistaken a '92 auto can do like 170 MPH, so that would mean it was definitely pulling in 4th gear. Something is not right with it.

Bump for ya

 

what is a full manual valve body? how will that help the trans shift to 4th at WOT?

 

Answer to last months question...The slippage of a torque converter is important for getting the car off the line from a standing start when torque multiplication is utilized. Once the car is at a higher rpm and a higher gear, torque multiplication is not needed. A slipping converter can actually eat hp and result in a lower speed and slower et. That is why some racers will lock up the converter in 3rd gear (and sometimes in 2nd although it is tough on the tranny) during a quarter mile run. If you are cruising on the street, that is another story. When you punch the gas pedal, you will need the transmission to downshift and the converter to slip to get the motor quickly into the torque band. The lock up thing is mainly for quartermilers. Willie

 

Brought over from parts for sale forum: I was looking for a 3.54 carrier in trade for my 3.73 or for an outright buy. The topic moved to the trans and my problem with no shift to 4th gear. (BTW, I have sent a PM to PeteK, but so far, no response). Steve

Quote:
Originally Posted by pologreen1 View Post
If you don't mind me asking.... Why the change of mind?


Well, since you asked... It a bit complicated..
Partly, It's kind of an experiment, and actually, I would rather buy a complete 3.54 carrier than trade so that if I decide I prefer the 3.73 gears, I would still have them. Here's the whole problem. For some reason, my 89 with a beefed up 700R-4 trans and the 3.73 rear end has run out of rpm's in 3rd gear, just before I get through the traps in a 1/4 mile! I found myself flat out at about 6200 rpm's with about 50 feet to go! I don't want to damage anything by over rev'ing so I thought going to the 3.54 would get me through the traps before I run out of gear.

I posted my problem here last week regarding the no-shift to 4th at WOT, but so far no one has been able to tell me for sure, why my trans won't shift into 4th gear at WOT. I have actually got conflicting opinions as to whether or not the trans does shift to 4th at WOT. My thinking is that it is reasonable to think that it should. Otherwise, how would you be able to run it to find the top speed of the car?

The transmission shop who built it went into it again last week and did something regarding opening a tiny hole just a bit larger in a plate in the trans, that was supposed to make the car shift into 4th. I tried it out yesterday and was still pulling hard at 105 mph on the freeway when I backed off. No shift.

Now, if I could get one of you guys who has a similar car with a 700R-4 trans go out on a freeway and floor it and come back and tell me if your trans shifted into 4th gear at some point. I mean, shouldn't it be like a passing gear where if you're cruising along and floor it, it down shifts to 3rd, and when the car gets up to 80 or so it shifts back into 4th gear?

Admittedly, I know next to nothing regarding auto transmissions, but I have owned other cars with them that when floored to pass, will kick back into passing gear and then will top out at 80 or so and shift into high gear, with the car at WOT.

Any expert trans guys that could help me here with some answers?

Steve
stevie1dr is online now Report Post Edit/Delete Message

 

No problem, PM me with your bank card number to cover the ticket and increase in my insurance rate.

 

It seems like at some point, someone has rebuilt that trans, and they have taken the original Corvette valve body, and put in a standard type valve body, probably with the shift kit mods allready done...

Tell ya what i would do, and this WILL work, sell that car, buy a 94 or 95, get TunerCat, make the cable you need to connect under the dash to a laptop, download the file from the PCM, open up the file and change the trans shift tables to make the trans shift any way you like. If you dont think you can do it, you can send me the file and ill change it for you.

Guarantee it.

 

I do not know what to tell you at this point.

I did not build your 700R4 transmission.

I do not know what rebuild "Hard' parts you used.

I do not know the the 2 digit paint code on the valvebody you are are currently using.
C4 valvebodies had a paint code original to help identify them.
It gets washed off with solvent during rebuilds.

I don't know if you are using your original Steel valvebody seperator plate or not.
2 digit stamped code too.

You provide "0" pics for me to analyze from here.

I drove my 87 vert last night again.
To get my kicks.........I floored the gas from 60 mph,
It down shifted from 4th, down to 2nd,
car shot ahead.....speedo numbers climbed very fast......
hit 3rd gear and slammed back in the seat,
at 114 mph with my foot planted on the floor my 700R4 trans blueprinted by myself made its WOT 3-4 upshift.
I kept my foot on the gas till I hit 150 MPH.

If you do not believe me...........
You are welcome to come to Illinois........
I will take you for ride in my 87 Vert.

If You are too scared to look at the speedo riding shotgun,

I will grab you with my right arm & pull your head over to look.

I have done that to a couple of friends in the past.

My buds don't call me "The Maniac" for nothing.

Brian R.

 

OK. Last night at the strip we adjusted the TV cable to leave just a small amount of slack at WOT. I haven't had a chance to try it yet, but will soon. Someone else mentioned a governor in the side of the trans that has springs that can be changed to alter the shift points of the gears. They suggested that when the trans blew that some debris may have gotten into it and is keeping it from working correctly. When they rebuilt the trans and beefed it up for racing it was also suggested that the builder may have neglected to check the governor and clean it out as well.

Monday, I will tell my builder to read these postings to see if anything might come to light for him as far as solving the problem.

For the most part, this shift problem isn't really a problem in terms of a daily driver. It goes through the gears all the way into 4th during normal driving and general cruising. It's just the WOT with no shift that is bugging me, and I would assume there has to be a fix for this somehow.

Thanks to all who offered there advice and opinions on what might be wrong. I do appreciate your interest and suggestions. I'll let you all know if and when we discover the proper fix for the problem.

Steve

 

Goodluck.

A pondering question to ask yourself is :

" Where did my original C4 Valvebody & matching separator plate go?"

A Chevy truck or Chevy Caprice valvebody drops into the C4 700R4 trans case just fine.
Does it perform like a the Original C4 Valvebody did at WOT on the 3-4 shift.

You are finding out yourself now...........NOOOOOOOO.

It will come to your realization sometime.

Brian

 

Duly noted Brian, and thanks. As I have said before, I don't have much in the way of knowledge regarding the trans but I will ask if the trans shop used my original C4 valve body and matching separator plate. If they didn't, and switched them out for some reason, where can I get the proper valve body and separator plate you refer to?

I do know that when they did the re-build they put in a B&M shift kit along with beefier parts to take the stresses of the additional hp. The shop is well known in my area for excellent work and was highly recommended by a local Corvette specialty shop who uses them regularly for transmission repairs. I'll be talking to the head man on Monday.

Thanks again!

Steve

 

You can call Dana at Pro Built Transmissions.
He is very busy, but it is very very knowledgable and a great rep. There are others that can help, he is just one of many that has helped me after my valve body was butchered. He rebuilt it to work as designed and it has been great ever since.
http://www.700r4l60e.com/

 

If youwant the trans to shift into the gear you want at the moment you want, you have to go to a Full Manual Valve Body. This is the second time I have posted this. Someone else asked what a full manual valve body is, in short it is a valve body that will have high pressure constant and will put the trans into the gear you want when you want. There is no hesitation, it is instantaneous. It does shift hard and it is like a mule kicking you in the back from first to second, but it is worth it. I investigated the Full Manual for a while before I went to it, and it solved the issue I had when AutoXing, I would have unpredictable shifting with the stock 4L60. I was looseing time. Last year the stock trans bit the bullet and I elected to have a Stage 4 4L60 Full Manual Trans by RPM Transmissions done. Some of the best money I have spent as far as driveline.

 

Big mistake my friend...
With a 4L60 yes, but if you were to go to a 4L60-E, no.

 

Yes Dana at Pro Built transmissions,

He guided me too on my 700R4 rebuild.

Much of my knowledge on 700R4's came from him too.

He is one of the best transmission mechanics in the world.

He is a GOOD MAN & deserves every bit of respect when you call him.

BR

 

With a 4L60 yes, but if you were to go to a 4L60-E, no.[/QUOTE]

Why not with a 4L60E?