The 700R4 Transmission, Chapter 1

I just scored this 700R4 transmission from a guy in Houston that is/was an idiot. I'm sorry, he just is. Anyway, after having him count the input shaft splines (30) and I could see the MD8 case in the ad pic, I decided to take the chance. Since the case is an MD8, and it had a 30 spline input shaft (the older 27 spline isn't as strong), and the fact that he said that he had paid $1,400 for it, but in the process of upgrading his Torque converter, the guy put spacers between the engine and bell housing (stupid or what?), because I suspect he did not jiggle it around enough to get the front pump dogs to engage, and thought it was in as far as it was going to go. What the heck, I paid $150 for it, which is the going rate for a trashed core...

MD8 case is the best/strongest case for 700R4 transmission.

Oil cooler line connections and throttle position feedback cable.

Tail Shaft casting number.

Update 2/23/2015 - I ran across an Ebay ad that had a picture of a 700R4 transmission painted the same color as the one I bought. The ad was placed by "Mad Dog Transmissions", so I called them and gave the lady who answered the phone these codes stamped on the top rear of the transmission. She confirmed that these codes mean: "RM" the initials of the person who built it, "L3" is Level 3 (650 HP rated), and the "2" means it has a number 2 shift kit already installed. Not to bad mouth MAD DOG TRANSMISSIONS, but you will see in later photos where I replaced the cast aluminum pressure plates with steel ones, which is THE ONLY way to go for a high performance transmission, maybe... ahahah. Additionally, it seemed that just about all the parts in the "guts" were stock parts, but then again, I'm no expert at this point, but I might be by the time I get done with this thing...ahaha

Gear shift lever and on the right, the connection for torque converter lockup signal.

Transmission manufacturing codes. It is a 1990 transmission (zero in first position) other than that, I forgot what they mean. oh well.

TC cable connection...

The tailshaft with the two horizontal mountings indicate that the tailshaft, at least, is from a Camaro/Firebird With Torque Arm Mounting. The mount is under the case, just to the left of the speedo connector, and not on the tailshaft. Read somewhere this tailshaft might be a Corvette ....

Original oil pump, which is ruined.

Old torque converter numbers. Did not use it, as I thought there could be some internal damage.

See that burn spot? That front edge of the torque converter rubbed on the pump dogs for a little while before it fell into position. Notice the little bitty dings in the slot edge where it knocked the dogs off the pump.

You can see one of the two broken dogs inside the seal. But that's ok. I can get a new 10 or 13 vane (latest design) pump internals for about 30 bucks. Will probably select a different torque converter anyway. As it turned out, I bought an entire new pump, as this one had lots of damage to the housing, too.

Case all cleaned up, pump out, drums and planetaries removed for rebuild/checking. Lots of old springs left over.

The remains of the oil pump. Not only did the "accident" obliterate the rotor and vanes, but the slide that the vanes ride on was broken into four pieces. Ugh. Bought a new ten vane pump, disassembled, checked all clearances, made valve modifications.

New 10 vane pump on the left, blue seal rings installed, O-ring on body, ready to reinstall. Old pump body on the right with deep scratches in the face of the pump area when the "accident" happened (caused by dumb ass installer). University of Texas wine glass in background. Ha.

These are the original cast aluminum apply pistons that I learned from an instruction video that have a habit of cracking due to high stresses. Recommended getting '93 or later steel pistons, which I did. These go to the dump. NOTE: See the last picture of this gallery for a picture of replacement forged steel piston that I replaced these with..Note : Don't think a transmission rated for 650 horsepower would have these pressure plates, but of course I could be wrong. Steel ones were not very expensive anyway...

Band, new pan gasket, and the 2-4 apply servo. Supposed to be a Corvette servo, though the numbers are from Transtar catalog, that was modified. See page in instruction sheets for what I did on the apply piston. Small parts on right are aux. control body and accumulator. Didn't use the gasket, as the new deep pan came with silicon gasket.

Front drum with Raybestos BRAND NEW Z-PAC clutch plates. Turns out there was ZERO wear on bushings and band and clutches. The other drum slides over the drum on the left. I did not replace any of the parts except for the steel pistons and kit parts. the reverse drum on the right is a little troublesome due to wear pattern ... looks like it's pretty much used for a long time, but.. Nobody has driven it/used it since it was rebuilt... hmmm.. the surface that the band rides on bothers me, but I'll use it anyway. Trying to keep costs down.... UPDATE: See Chapter 2.... I eventually bought a new drum....

The Transgo kit has a number of aluminum plugs to block off some of the holes in the separator plate to change fluid flow paths/characteristics. Hammered plugs before filing flat. I didn't see any evidence of any modifications to the plate nor anything else in the valve body. Everything mentioned in the Transgo instructions for "stock" parts to do something with were what was in this transmission.

One of the holes (number 5) to plug was nearly square.

Shiny spots are aluminum plugs that you first, chamfer the hole, hammer the plugs on a piece of steel or concrete, then file flat with the plate. Works pretty cool to plug existing holes.

They call these snail trails in the hood. HA. Seriously, whoever designed this thing is a friggin' GENIUS ! Probably was a team effort though.

Valve body and spacer plate. The plate looks like it's all scratched up but looks like somebody used a wire brush on it for some reason.. The scratches are very superficial.

Mine is a TYPE 2 body, so all instructions for TYPE 2 and Auto shift were followed. Also, I used the "Automatic Shifts" series of instructions rather than the "Stick Shift".

This is the guts of a 700R4 GM transmission. YIKES !

Bought a TransGo 700-2&3 kit to upgrade for performance. Did the procedure for FULL RACE-AUTOMATIC. The STICK SHIFT option just doesn't sound appealing. I NOTICED THAT THE INSTRUCTION SHEET WAS PRINTED IN 2009, SIX YEARS AGO........WONDER IF THERE'VE BEEN ANY CHANGES TO THE KIT SINCE THEN ?? SLIGHTLY CONCERNED......

Drills and a couple of other tools were supplied in kit along with a million springs replacement valves and other stuff.

WHEW !

Didn't have to do much on this page, as I'm going for "auto shift". I interpreted this instruction sheet to say that I only put TWO check balls in the valve body, leaving out one on the lower left.

This is getting CRAZY. Surely do hope it works. Circled Items are the things I did per the instructions... hmmm

Boy, making all these modifications surely seems crazy. Hope it works. 4 check balls per this page, making a total of 6 ???

UPDATE: This 2-4 Servo was removed and a SONNAX full kit was installed. See Chapter 2 for the installation of the SONNAX. .....As it turns out , the numbers on the 2nd piston are TranStar part numbers (61986-1 and -2 with another mark - T/S which I guess means TranStar), which indicate some sort of after market Corvette servo, maybe....The diameter of the 2nd piston shoulder that slides into the housing is 1.75". Don't know what a Corvette servo is supposed to be..

How in the world did those guys figure all this out? Had the second type, so put in the new capsule supplied with the kit.

Took about 2 minutes once I got the drum out.

Bought a new "spring ring" with the 2nd type features. Type "1st type" was in the transmission. Did not reinstall the 3-4 factory springs.

Mine had the cast aluminum piston/springs shown on the left (As in, originally from GM). Got a new 2nd type springs and steel piston, changed out the springs to the kit springs. The installation washer is used when you put the thing in a press to take off the retainer snap ring to avoid bending. ATTENTION ! GO BACK TO THE TOP OF THE PAGE, CLICK ON "HOME", THEN SCROLL DOWN AGAIN TO "THE 700R4 TRANSMISSION, CHAPTER 2" FOR THE "SECOND BUILD/REBUILD"... PISSED ME OFF..