700R4 alternatives

[minifridge1138]

Hello everyone,

I have the 700R4 in my corvette and i'm wondering what options i have. It is a fine transmission, but i'd prefer something with 5 or 6 gears. With the 700R4, the shift from 1st to 2nd drops me out of the power band.

Does anyone have any recommendations?

Thanks!

 

[toptechx6]

You should probably post this in the C3 section, but I'll give you my two cents. The crossfire engine in your 82 is far from the strongest ever put in a Vette and at least in 82 there were no other transmissions offered.
Converting to a manual trans is a huge undertaking and unless you buy aftermarket you will not find a bolt in with more than 4 speeds.
A better solution might be a rear axle ratio change, it should improve low end performance though you may sacrifice a little fuel economy. A higher stall torque converter would help too.

 

[KANE]

You should probably post this in the C3 section, but I'll give you my two cents. The crossfire engine in your 82 is far from the strongest ever put in a Vette and at least in 82 there were no other transmissions offered...

Technically, the C4s came with more overdrive options than the C3s. ZF-6speed, 4+3, 4l60E, and 700R4 were the transmissions used over the period of 84-96. I think the C4 section is perfect for asking about overdrives seeing that the C3 only had it for a year.

Minifridge- you have lots of options. It just comes down to cost and matching that to your objective.

Gear Vendors has a splitter that mounts to the 700R4 tail.
http://www.gearvendors.com/faq.html

Back to transmissions...

6 speed Richmond-
http://www.richmondgear.com/01sixspeed.html

6 speed T56-
http://www.keislerauto.com/

You'll spend about 3k on any of these swaps. Read up and decide if this is right for you. Remember, you have a lot of options!

 

[toptechx6]

Technically, the C4s came with more overdrive options than the C3s. ZF-6speed, 4+3, 4l60E, and 700R4 were the transmissions used over the period of 84-96. I think the C4 section is perfect for asking about overdrives seeing that the C3 only had it for a year.

Minifridge- you have lots of options. It just comes down to cost and matching that to your objective.

Gear Vendors has a splitter that mounts to the 700R4 tail.
http://www.gearvendors.com/faq.html

Back to transmissions...

6 speed Richmond-
http://www.richmondgear.com/01sixspeed.html

6 speed T56-
http://www.keislerauto.com/

You'll spend about 3k on any of these swaps. Read up and decide if this is right for you. Remember, you have a lot of options!

See paragraph #2, none are bolt in, and all are big bucks.

 

[KANE]

See paragraph #2, none are bolt in, and all are big bucks.

I've done non-factory engine and transmissions swaps with lots of custom work. They can all be bolted in- provided the necessary modifications are made. Not always "big bucks" either- especially when I do all the work myself.

To my point- Grumpyvette, Bossvette, Patsntrovette, and many others have done all manner of swaps before. It isn't rocket science. It just takes time and know-how... often to the will to reach beyond one's skill set.

Besides- lots of good stuff here-
http://www.corvetteactioncenter.com/forums/forumdisplay.php?f=248

 

[toptechx6]

I worked in the car repair business for over 30 years and would agree that anything is possible, to me the question is one of practicality. I would be shocked if those mentioned could ever recoup the dollars invested in radical conversions performed even if they don't count their own labor. Most performance modifications subtract from the value, rather than enhance it except when selling to another gear head who happens to like the changes.

Certainly a judgment call, and I understand some people get enjoyment just out of making such things happen and could care less how much it costs, but I think doing so should be represented fairly. These conversions are not for everyone and certainly not those without a fat wallet or the ability to do their own work, preferably both.

 

[Hib Halverson]

Hello everyone,

I have the 700R4 in my corvette and i'm wondering what options i have. It is a fine transmission, but i'd prefer something with 5 or 6 gears. With the 700R4, the shift from 1st to 2nd drops me out of the power band.

Does anyone have any recommendations?

Thanks!

If your 82 is stock or near stock, the 1-2 shift does not "drop" you out of the power band. What it does do is shift too soon at part throttle. That's typical of the trans calibration back then for that and other transmissions. It was one of the few ways car companies could meet fuel economy.

The ratio spread in the 700R4 is the same as what was used in the 4L60 and 4L60E until the six-speed auto was introduced for 2006. The grear ratios, coupled with torque converter action and the L83's low-end torque, does not upshift out of the engine's power band.

You need to do three things, I think.

1) If the trans is high-mileage, consider an overhaul.
2) Install a "shift-kit".
3) change the axle ratio. I believe 3.08 and 3.55s are available. If the engine is stock or near stock, I'd use 3.55s. If the engine is somewhat to highly modified but is street-driven, I'd go with the 3.08s.

It's suggested elsewhere to change the converter. I'd avoid that unless the engine is modified and the end use is mainly drag racing.

 

[minifridge1138]

Some very good ideas and suggestions.

I have been considering a change in the rear gears (it has 2.7 in it now). I've been told that this is something best left to a professional (something about using shims to get the gears to align correctly). Is it really that hard?

I understand that modifying things will hurt the value, but the previous owner already took care of that. The crossfire is gone, and I now have a carburetor. I'm just looking for fun to drive. It already is, but it doesn't have the pep that I'd like.

Someone recommended a shift kit, is there a particular brand I should look for?

Maybe a shift kit + 3.55 gears will give me the pep i'm looking for.

Thanks for the suggestions!

 

[toptechx6]

Changing the gears isn't so much a question of being difficult as it is being precise. It is a job where experience will help tremendously, it also requires several specialized tools, spreader for removing the carrier from the pumpkin, pinion depth measurement tool, pullers for removing bearings and a hydraulic press for installing them, micrometer for measuring shims, and a fine torque wrench for measuring bearing preload.

It is not usually recommended for weekend mechanics for the above reasons. No doubt you could get a new ring and pinion installed but it could well be noisy and might not be durable if bearing preload wasn't set properly.

You can save on the labor by removing the pumpkin from the car, then taking it to someone with the tools and skill to set up the gears, that would be my suggestion.

 

[Edmond]

DarkShark,

You're just like my neighbor, you make it look easy!:L

 

[Mad-Mic]

Changing the gears isn't so much a question of being difficult as it is being precise. It is a job where experience will help tremendously, it also requires several specialized tools, spreader for removing the carrier from the pumpkin, pinion depth measurement tool, pullers for removing bearings and a hydraulic press for installing them, micrometer for measuring shims, and a fine torque wrench for measuring bearing preload.

It is not usually recommended for weekend mechanics for the above reasons. No doubt you could get a new ring and pinion installed but it could well be noisy and might not be durable if bearing preload wasn't set properly.

You can save on the labor by removing the pumpkin from the car, then taking it to someone with the tools and skill to set up the gears, that would be my suggestion.

he is correct. unless you have setup rears before i recommend letting a professional do it.

it has to be precise and have enough play in it but not slop. if done wrong it will cost you alot more money to fix.

how about holding 1st gear longer manually? thats what i would do

just get some nitrous and end your problem

 

[Pete K]

Hello everyone,

I have the 700R4 in my corvette and i'm wondering what options i have. It is a fine transmission, but i'd prefer something with 5 or 6 gears. With the 700R4, the shift from 1st to 2nd drops me out of the power band.

Does anyone have any recommendations?

Thanks!

I know I am digging this thread up from the basement, but things have changed a bit since this thread was created.
There is an aftermarket 6 pinion planetary gearset avaiable now for the 700r4/4l60/4l60e/4l65e.
I did purchase it, and do a build up for my 87, but have not yet installed the trans, or track tested it.
I forget the ratio's offhand, but something like a 2.74 1st gear, and a 1.60 2nd gear. 3rd stays 1:1 and 4th remains .070:1
It should cure the crappy 1-2 shift bog these things are known for.
On my combo, I am hoping to pick up 1-2 tenths in the 1/4 mile, but we'll see.

 

[toptechx6]

I know I am digging this thread up from the basement, but things have changed a bit since this thread was created.
There is an aftermarket 6 pinion planetary gearset avaiable now for the 700r4/4l60/4l60e/4l65e.
I did purchase it, and do a build up for my 87, but have not yet installed the trans, or track tested it.
I forget the ratio's offhand, but something like a 2.74 1st gear, and a 1.60 2nd gear. 3rd stays 1:1 and 4th remains .070:1
It should cure the crappy 1-2 shift bog these things are known for.
On my combo, I am hoping to pick up 1-2 tenths in the 1/4 mile, but we'll see.

Look forward to hearing your results Pete, know you have been dying to try this gear set. I'm guessing the cost is substantial, but should be a nice improvement.

 

[Pete K]

Look forward to hearing your results Pete, know you have been dying to try this gear set. I'm guessing the cost is substantial, but should be a nice improvement.

I sure am.
I holed a piston last year, just before I was to rip out the normal trans, and install the hybrid.
Rather than fix the 383, I had a 406 bullet on the stand.
Workin on the tune up now.
Once it is good to go, I will baseline it, swap it out, and document the result.
If it doesn't work well for my combo, it should still be an viable option for other combinations.
@ $1300 bucks for the gearset only, expensive change.

 

[toptechx6]

I sure am.
I holed a piston last year, just before I was to rip out the normal trans, and install the hybrid.
Rather than fix the 383, I had a 406 bullet on the stand.
Workin on the tune up now.
Once it is good to go, I will baseline it, swap it out, and document the result.
If it doesn't work well for my combo, it should still be an viable option for other combinations.
@ $1300 bucks for the gearset only, expensive change.

Thought I recalled you getting ready to try this awhile back, the holed piston explains the delay. I'm guessing your work schedule and travel has not helped either.
Best of luck sorting out the tune, hope the combination exceeds all expectations after all the time and money invested, keep us in the loop.

 

[WhalePirot]

A better solution might be a rear axle ratio change.

That's what I thought and did with my original engine. the rather low-peaking power band of the Crossfire made me regret that decision very quickly for my street driving.

Who resurrected this antique thread?? :confused

 

[Pete K]

That's what I thought and did with my original engine. the rather low-peaking power band of the Crossfire made me regret that decision very quickly for my street driving.

Who resurrected this antique thread?? :confused

Some good, honest soul who wanted to provide helpful updates for those curious.
Shame on him for hoping to help his fellow corvette owners.