Hi, everybody, I need some advice from some experts here.....I have a 1980 corvette that I am thinking about putting a 700r4 tranny into. I have what may or may not be a terriffic deal before me. It seems that a friend of mine has a 1982 corvette with a stroker 383 in it, and he is willing to sell me the 700r4 out of it because he put a tremec 5 speed in it. The reason he put the 5 speed in it is because, according to him, the 700r4 will not hold 1st gear past 3000 rpm no matter what he does. Now, I know that the early 700r4 isn't known for being the most rugged tranny out there, but this one has just had $2,200 worth of work done to it at a local transmission rebuilder who has an almost legendary reputation around these parts as a builder of rugged hotrod automatic trannys, so I am reasonably certain that this tranny has been rebuit to take the abuse. My only real question is, what is the deal with only holding 1st gear to 3000 rpm? He says it always did this, from the day he bought it, and that it is normal. Is this so? And if it is normal, what can be done about it? I can get this tranny for $250.00, but if it just won't hold 1st gear past 3 grand, I'm probably not interested. Also, will I still have to change the transmission crossmember and shorten the driveshaft? Thanks for help.


Scott

 

I have a 700r4 in My '81, and although it is not from an '82 Vette, it will hold first and second all the way to 5,200 rpm's (which is where I want it to shift). I don't know why it could not be set up to shift where you want it to if it is in proper working order. I would discuss it with the shop that did the work on it. God bless, Sensei

 

I guess what I'm really looking for is two things: 1-82 corvette owners to tell me if this is nonsense, and 2-700r4 experts to tell me if this can be easily fixed, and will I have to change x-member and chop the driveshaft. thaqnks again.



Scott

 

If thats an 82 700R4 trans with a rebuild costing over $2K {more than the price of a new one} from a " legiondary" mechanic, and it still won't hold 1st gear past 3K rpm as required by you. then I think you've already answered your own question.. Find a new trans and mechanic.

 

So, not holding 1st gear is not normal behavior for a 1982 corvette 700r4 transmission,is that what you're saying?

Scott

 

No that isn't normal. I have an 82 with the stock transmission in it and it'll hold past 3,000. Perhaps the throttle valve cable is not adjusted correctly causing it to shift early. Those pesky T.V. cables are paramount with 700r's, and a cable not adjusted properly can burn up the 3 4 clutch pack in no time. Now as to whether or not it's a deal. $250 for a transmission is hard to pass up, if you are in need of one. If yours works great, then I would hesitate to buy it. Pre 1988 the 700r's were pretty horrible, and only had a 27 spline input shaft. Why anyone would put $2 grand in a pre 1988 700r is beyond me.

Nathan

 

I have an 82 and the 700r4 never gave me any trouble, and it would definately rev above 3000 in every gear. And then held at 125 mph
in 4th gear. I since then switched to a richmond 6 speed. In your car you will probably need to modify your crossmember, and driveshaft.

 

There are some questions and comments I have for you,is this a good friend that you trust? Is your engine stock? How long had the trans been used in your friends car? You said that the trans builder is well known in your area, go to him and inquire what the problem could be. Get an estimate of the cost of repair if any? Is the estimated price of repair reasonable? Consider the cost of retrofitting the trans there is no doubt that the price is right @ $250.00 and the benefits should be good enough to offset the swap into your car.With these answers it would be obvious that you will come up with the correct answer you need to go on with the deal. Good luck and enjoy the sound the engine makes when it goes ahhh as it shifts into overdrive.

 

I am not a fan of the 700, the one I had built here 11 years ago for my '72, which required me messing with the mount by totally modding it to fit the tranny new holes, and basically re designing it....then shortening the drive shaft by 2.5 inches and rebalance when that was done at a shop for 100 bux.....then there is the kickdown/throttle cable to your carb interface/brackets and then proper adjustment, then the lockup wiring/plug/controller setup....then the shifter which is only 3 speed and you can modify the existing notch plate or buy a new one....then to mark the console somehow if you that picky.....MY '72 SB here was a Muncie car so I had to cut/widen the pass side tunnel to clear the tranny housing///PIA, then the problem of the ebrake cable routed to the left off the handle assy to clear the yoke being far back due to tranny length....

then the builder of my tranny went with the Superior/Fairbanks rebuild kit, and that's the way mine reacted also...mine was a 'late 87 up unit....first gear was short....better then 3000 rpm but not a whole lot, try your throttle cable adjustment first....

the thing will downshift and hold in 3rd gear no matter what speed you are going, I have a 336 gearset which is unchanged since new....

ONLY when you lift a bit will it upshift into 4th, then if you get back on it down to 3rd again...PIA, no cure....

NOW, IF I was to rebuild one I would use NO OTHER THEN THE TRANSGO SHIFT KIT>>>>>>

after about two 3/4 clutch packs and then having it start with slipping again....I tossed the towel on it about 3 years ago....and rebuilt my own 200 4r tranny, which is basically a bolt in tranny sets on the crossmember, less width problem, lighter, just as strong, better gear ratios, holds 4th at WOT, and with my TRANS GO shift kit will bang gears like a dragracer...

much better suited to my car.....

 

Corvette/Police transmissions do not do this.

 

That tranny has a serious operational problem. It could be as simple as a TV cable adjustment....but I doubt it. More likely, it has 'trash' floating around in it from some damage incurred during hard use. The trash is not sticking some shift valves. He may be your 'friend' now, but if you buy that transmission, he won't be for long!

 

You want the 3/4 throttle valve. Pretty sure the cops cars have it. So does mine. So I don't have your problem. Put your foot into it and let her stretch
http://www.bowtieoverdrives.com/hot/
Go onto their website. Lots of good information !

 

Thanks for all the info, guys, I will think on it some more, do some detective work, and make my decision.

Scott