Aftermarket 700R-4 Install in 1982

[nmaier88]

I have a 1982 Corvette that came with a 700R-4 stock. I just bought a 700R-4 from a transmission builder in FL which should get here tomorrow. I was wondering if I am going to need to reuse the tailshaft section of my original transmission. I heard the tailshaft of most 700R's are a different length than the corvette 700R's. Is this correct? Thanks,

Nathan

 

[minifridge1138]

I have always heard that any 700R4 is a direct bolt in for 1982.
I know that people putting a 700R4 in a pre-1982 C3 need a new tail shaft because the 700R4 is longer than the AT used in 1981 and earlier.

To the best of my knowledge, you should be fine.
Maybe someone with more knowledge will disagree.

Good Luck!

 

[KANE]

It is pretty straight forward. Some folks will say (Bowtie overdrives) the cross member on the 82 doesn't align the engine properly, but the rest of the install is the same between an early 700R4 and a later 700R4.

Just make sure the TV pressure is set correctly and you hook up the TV cable. Without the TV cable, your transmission will ruin itself very quickly.

 

[Peer81]

I think the only thing you need to switch is the tailpiece. The 82 tailpiece isn't a common one but if you have a 82. It's only 4 bolts and ready to go

Groeten Peter

 

[nmaier88]

Hmm, well maybe what I have heard about the 700R-4 tailshaft section in the 1982 being a different length is incorrect (I sure hope so). Peer81 - You are saying I need to switch the tailpiece but not the output shaft (tailshaft)? Wouldnt the tailpiece be shorter or longer because the output shaft is shorter/longer, or is that not true? Thanks for the help guys.

 

[topless82vette]

Hmm, well maybe what I have heard about the 700R-4 tailshaft section in the 1982 being a different length is incorrect (I sure hope so). Peer81 - You are saying I need to switch the tailpiece but not the output shaft (tailshaft)? Wouldnt the tailpiece be shorter or longer because the output shaft is shorter/longer, or is that not true? Thanks for the help guys.

I put a 1990 corvette 700r4 in my 82 and it fit perfectly. I used my 82 tailshaft housing BUT I can't remember if the output shaft splines came out to far or were in farther then the 82 700r4. Either way though it hasn't been a problem one thing I did notice though its highway rpms decreased noticeably over the 82 700r4. I used my stock speedo gears as well so the 90 700r4 might have a different overdrive gear ratio over the 82 700r4.

Aside from the output shaft thing everything bolted right up without a problem. Hope that helps and you will like that newer 700r4 much nicer shifts

 

[Peer81]

A 82 or 90 700R4 are the same in dimensions. The 90 (4L60) is a upgrade from the original 700R4 (I also have a 90 Corvette auto). You only need to switch the tailpiece because it has a different mount for mounting it to your crossmember. So I think you don't need to alter anything. But I have a 81 so I don't know exactly for a 82. Good luck!

Groeten Peter

 

[82X-FireVette]

The Corvette 700R4 is 7/8" shorter than the standard version of this transmission. The output shaft is 1 1/8" shorter. The tail housing is easy to replace, the output shaft is not. You have to disassemble most of the transmission to get at the snap ring that holds the shaft in. Just to get the snap ring out is a chore as it is inside the rear planetary gear assembly that is tight for room. The snap ring pliers must be long and narrow to reach in there. There are other differences such as a larger servo, different accumulator springs, and governor.

 

[GT6Steve@aol.com]

Thread drift...

At the risk of drifting this thread into oblivion.

I've been doing a lot of highway miles with my 81 and in the 1/2 hour periods behind the wheel I've pondered whether a 700R4 conversion would be viable. I'm getting 14-15 MPG so gas savings don't really calculate out. My 350 trans is good so I'm not hardup for a conversion. Then, that specific tailshaft is rare and valuable.

My thinking is that it's not viable?

The Corvette 700R4 is 7/8" shorter than the standard version of this transmission. The output shaft is 1 1/8" shorter. The tail housing is easy to replace, the output shaft is not. You have to disassemble most of the transmission to get at the snap ring that holds the shaft in. Just to get the snap ring out is a chore as it is inside the rear planetary gear assembly that is tight for room. The snap ring pliers must be long and narrow to reach in there. There are other differences such as a larger servo, different accumulator springs, and governor.

 

[bossvette]

I'm putting in a standard length 700R4 in a 76 I was aware that there are differences between the Vette version and the standard version but being an old hotrodder I am making do with what I have. I don't have any pics of the underneath yet but I just modified my stock 4-speed trans mount and I am using a shifter from a C4.

I am not using one of the "Kits" but its a complete DIY job.

 

[Curtis]

I'm putting in a standard length 700R4 in a 76 I was aware that there are differences between the Vette version and the standard version but being an old hotrodder I am making do with what I have. I don't have any pics of the underneath yet but I just modified my stock 4-speed trans mount and I am using a shifter from a C4.

I am not using one of the "Kits" but its a complete DIY job.

Mine is also a standard length unit, but the inside is built to the hilt (from Florida). The original 4 speed crossmember was welded to the frame so i cut it off a few inches from the frame and bolted in 1/2 x 3 flat steel and welded a plate on that to mount the tranny.The driveshaft had to be shortened ($35 cost). Works good for me and is easy to remove should i ever have to take the tranny out. It also left me enough room to install the exhaust without a lot of remanufacturing..Using a '76 shifter and cable with the modified plate to accomodate the OD . DIY is the only way at my house. ONe thing to keep in mind is the final mounting angle so your pinion angles are within spec. I didn't think of if before i started but i should have just measured the distance from distributor to the firewall and then made the new mount so that distance was the same. oh well ..

 

[nmaier88]

I finally found the answer I was looking for and just wanted to set the record straight. There are 4 output shaft (tail shaft) lengths for the 700R-4 and they are:


4WD
Syclone 4WD
C4 Corvette
2WD (All Others)

The 1982 Corvette was the only C3 Corvette to come with a 700R-4. The Output shaft of the 1982 Corvette's 700R-4 falls under the 2WD (All others) Category and is not the same length as the C4 Corvette output shaft. This being said, I got my aftermarket 700R-4 with the 2WD Non-Corvette output shaft and installed it last weekend. Everything went well and it runs great.

Nathan