Advise before I go screw things up again 700R4

[Marv02]

Ok I need to find out what the difference between the 1986 Corvette 700R4 and a normal 700R4 Transmission.

What I know so Far.

Corvette 700R4 has different tail housing and a V on the side of the case.

The 700R4 with an X on the side are truck Type case made thicker I read some where they have longer tail shat.

The other types are for cars and have a shorter Tail shaft.

I found a Killer deal on a 700R4 that holds up to 450 HP more than what I need it for so this should work for me but the guy telling me all I need to do is put my Vett tail shaft housing on it and it ready to go it for a normal car.

I rather hear from, you Vett guys before I make another mistake and buy the wrong parts.

 

[John Robinson]

Lets look at why the tail shaft housings are different lengths. The first and most important reason is because the Out put shaft from the transmission is not the same length. It is not uncommon for a manufacture to utilize a base gear box in a variety of vehicles by simply changing the output shaft. Because of this the tail shaft housing becomes a support for the output shaft at the connection to the drive shaft. (that's a lot of shafts)Finally the tail shaft housing can be cast to provide different mounting points to secure the transmission into the car.

So that's why I would keep looking if I were you for the proper unit.

 

[toptechx6]

I agree with John, and will add one thing he did not mention. Changing the tailshfaft or extension housing is simple enough, four or five external bolts, the longer output shaft on the other hand requires complete disassembly of the transmission to do properly. If you are going to take the entire trans apart why not rebuild yours?
I have heard of people cutting down the output shaft instead of removing it and replacing it properly, but certainly would advise against doing that.

 

[boomdriver]

There are differences in the valving and servos. The standard or typical 700 has some "kit" servos available and valve kits. The vette 700 has its own pieces that are a step up. So a HD kit for a 700r4 is sort of a step backwards.
The tail-shaft housing is simple to change, but the other guys are right. The shafts inside are the problem. The tail housing accepts the yoke shaft but the drive inside has to be the right length for the yoke shaft to fit into. That tail housing is also the attaching point for the "C" beam on the corvette. SO that absolutely has to be correct.

I'd keep looking or have your old one rebuilt by someone familiar with the corvette needs. All these trans shops think that a B&M shift kit and some blue RTV makes a vette transmission...it does not. Don't let them to talk you into some exotic torque converter with some radical stall speed, or some junk shift kit that will waste your U-joints. They will try.

 

[vetteoz]

The vette 700 has its own pieces that are a step up. So a HD kit for a 700r4 is sort of a step backwards..

The Vette differences are only different shift points/ firmness achieved with different accumulator springs , boost valve and governor calibration along with the larger " Corvette " servo. All hard parts are identical

One would like like to think that a "450Hp " rated trans has been fitted with a shift kit and parts superior to the stock Vette ones.
I have been running a car T700 with cut down output shaft behind my 500Hp 383 for four years no problems

 

[boomdriver]

The Vette differences are only different shift points/ firmness achieved with different accumulator springs , boost valve and governor calibration along with the larger " Corvette " servo. All hard parts are identical

One would like like to thing that a "450Hp " rated trans has been fitted with a shift kit and parts superior to the stock Vette ones.
I have been running a car T700 with cut down output shaft behind my 500Hp 383 for four years no problems

One thing that I do believe everyone would benefits from, in stock 700s or upgraded, is the use of synthetic trans fluid.

Fleet studies show a dramatic drop in trans failure when fluids were switched from stock type fluid to synthetic.

 

[Marv02]

I rebuilt my 700R4 once my self when I put my new hopped up motor in the car.

This build been Murphys law most of the way so far what can go wrong has gone wrong.

I pruchashed a rebuild kit from Monster Transmission Nightmare wrong parts wrong seal had to wait for replacement parts to show up it took at least 1 month more playing the dog and pony show with them.

Every time I start working on the 700r4 I found out They has anouther wrong part to put in the kit. Nightmare I would never buy a rebuild kit from them ever again.

Purchased a New $380.00 lock up converter for the tranys rebuild put all back in the car I could back out of the garage fine but sliped very bad going foward.

I pulled the pan off to find clucth and little metal shavings in the pan I not happy at all.

I don't know if I trashed my New converter or not I going to try to have it flush out.

I not going to rebuild it my self ever again I going to have it done this time around.

I have a local shop that rebuilds trans but he want $1340.00 to rebuild a built trans But all I hear is good things about his work.

I can get a stock trans built for $600.00 range.

But will a stock 700R4 hold up to what I have done to the motor not a lot of HP but is to much for a stock trans to hold up to.

360 to 375 HP and about 425 TQ.

I not planning or going to beat on the car trying to make it a daily drive soon for a couple years I selling my 2006 Dodge truck to buy my wife a new car for her.

Don't worry still have her 2001 Dodge 3/4 ton V-10 Viper motor truck that gets 10 MPG on a good day down hill with the wind behide you it will pass every thing but a gas station LOL to drive around when the weather get bad or when I need to haul something.

 

[boomdriver]

I rebuilt my 700R4 once my self when I put my new hopped up motor in the car.

This build been Murphys law most of the way so far what can go wrong has gone wrong.

I pruchashed a rebuild kit from Monster Transmission Nightmare wrong parts wrong seal had to wait for replacement parts to show up it took at least 1 month more playing the dog and pony show with them.

Every time I start working on the 700r4 I found out They has anouther wrong part to put in the kit. Nightmare I would never buy a rebuild kit from them ever again.

Purchased a New $380.00 lock up converter for the tranys rebuild put all back in the car I could back out of the garage fine but sliped very bad going foward.

I pulled the pan off to find clucth and little metal shavings in the pan I not happy at all.

I don't know if I trashed my New converter or not I going to try to have it flush out.

I not going to rebuild it my self ever again I going to have it done this time around.

I have a local shop that rebuilds trans but he want $1340.00 to rebuild a built trans But all I hear is good things about his work.

I can get a stock trans built for $600.00 range.

But will a stock 700R4 hold up to what I have done to the motor not a lot of HP but is to much for a stock trans to hold up to.

360 to 375 HP and about 425 TQ.

I not planning or going to beat on the car trying to make it a daily drive soon for a couple years I selling my 2006 Dodge truck to buy my wife a new car for her.

Don't worry still have her 2001 Dodge 3/4 ton V-10 Viper motor truck that gets 10 MPG on a good day down hill with the wind behide you it will pass every thing but a gas station LOL to drive around when the weather get bad or when I need to haul something.

I think a stock trans would hold up ok.The problem is that when you buy one from some shop how do you know whats in it? They don;t even know half the time....transmissions get hauled into most shops by trucks and hauled off to rebuilders somewhere else.Lots of (big name) shops just do installs and minor service. Complete teardowns are done elsewhere and trannys are simply swapped out. The big-name shops, anyway.
The small independent shop is probably the best bet for getting a good one, or buying one that you KNOW came out of a vette that was wrecked or converted.

I'm more interested in getting the trans cooler hooked up on mine than the outside engine oil cooler. If well maintained, these 700r4s are as solid as a rock.
Good fluids, filter changes and enough fluid cooling, they are fine.

 

[Marv02]

The trans cooler was easy just cut your return line from the Rad and plumb a hose to the front of the A/C condenser then back to the other half of the return line going back to the trans.

I using a 18000 GVW cooler on mine it should help.

You going to have to cut and trim the rad shrould to make them work no big deal.

The Oil cooler has already made a big diffrence keeping the oil temps down.

On Cam Break in I have the car still on jack stands in my garage it about 100 degrees out when I did so the water temp got up to 220 before the fans kicked in the oil temp stayed about 178 more or less.

This inside a hot garage during the hot summer day NO outside air flow comming though the garage either.

I mite down the road when the vett funds get back up there get a 4 core rad then the car should run very very cool.

I'm more interested in getting the trans cooler hooked up on mine than the outside engine oil cooler. If well maintained, these 700r4s are as solid as a rock.
Good fluids, filter changes and enough fluid cooling, they are fine.

 

[boomdriver]

The trans cooler was easy just cut your return line from the Rad and plumb a hose to the front of the A/C condenser then back to the other half of the return line going back to the trans.

I using a 18000 GVW cooler on mine it should help.

You going to have to cut and trim the rad shrould to make them work no big deal.

The Oil cooler has already made a big diffrence keeping the oil temps down.

On Cam Break in I have the car still on jack stands in my garage it about 100 degrees out when I did so the water temp got up to 220 before the fans kicked in the oil temp stayed about 178 more or less.

This inside a hot garage during the hot summer day NO outside air flow comming though the garage either.

I mite down the road when the vett funds get back up there get a 4 core rad then the car should run very very cool.

well, I got my cooler mounted in front of the a/c condensor. I laid aluminuim C-channel across the width of the lower baffle then set the cooler in the C channel. I set it more to one side so the opposite side got a free flow of fresh air. I have not plumbed it yet, and was thinking of using this one for th trans and I'll work out the eng oil cooler later. My engine oil is no longer a serious issue after the success I had with the big all aluminum radiator...2- 1" rows. Its so thick that the rubber blocks have to be cut out to accept the new radiator. Thats keeping the engine temp down to 200 or less on a 105* day with a/c on. So right now I'm more worried about the trans. I'll get you the link to the place where I bought my radiator....$229 and came with cap, low sensor and polished up like grandmas silver set.
Since my nose is getting full, I'll have to find a new place for a eng oil cooler to mount so it can get fresh air too.

 

[Marv02]

Money Money or Lack of Money

Well it looks like with any luck I have the money for a Built Trans around end of next month.

So I am going to order for now a New Front Y pipe with out Pre cats and a new 3 Way Cat I tryed to remove the stock cat fronm the old Y pipe It will not come off with out destroying it.

I wish I could reuse the stock cat for now but it will not come off I wills screw with some more this comming week before I order the new cat.

I also going to need a new air pump mine sounding likeit on it last leg.

I E-Mailed Huges Transmissions to see if I can send them my New Convertor back to them so they can flush or what ever they need to do to se if they can save my New Convertor that has 20 mintes of run time on it.

But on the bright side this Hick Up once again getting the car back on the road gives me more time to tie the wire loom up better tie up lose ends better, found a better way to run the oil cooler lines Ect.

So maybe this ended up beening a good thing after all Knowing the car will be 100% right when it comes off jacks.

Or untill next year when I save up the money to rebuild the rear end, New bearings seal Clucth pack U joints Bushings and all wheel bearings.

Oh Ya for everyone that has helped out with my Build I must say Thanks.