700r4?

[BigGun J]

Question about tranny identification. There is a 700R4 core for sale in the area. The listing said it is out of a 88 GMC 2500 2WD. I asked the seller if it had the big K embossed on the bell housing. He said the only identifiers he can find are MD8 & 16. No K? What tranny is it? I am looking for a later model 700R4 to rebuild for a 4x4 project.

Thanks, Jim

[DA BIG ONE]

Question about tranny identification. There is a 700R4 core for sale in the area. The listing said it is out of a 88 GMC 2500 2WD. I asked the seller if it had the big K embossed on the bell housing. He said the only identifiers he can find are MD8 & 16. No K? What tranny is it? I am looking for a later model 700R4 to rebuild for a 4x4 project.

Thanks, Jim

The enhanced 700r4 case always has a good sized 'K' cast into it, if not stay away, stay far away.

"No K, not ok!"

[EWC]

MD8 is the 700R4 , MT1 is the 4L80E .

[Robyn]

The "K" Case is the HD unit that is designed for the 4X4 applications and has the beefier bellhousing that accepts the heavy aluminum lower cover.

The 700 innards are fine from 87 on until they went electronic.

Now if you are going to use it for a grocery getter the standard case will be fine even in a 4X4. (87 and later)
Now if your planning to go out in the sticks and beat it or tow some heavy loads then leave it alone and go for a K case.

Any of these, even the K case units need a lot of lovin on the inside to make them worthy.

Input drum/shaft assembly needs to be upgraded as does the front and rear sprag/roller locks. The high clutch pack needs upgrading as does the 2-4 band. The sunshell also is weak and needs to be upgraded to a unit like the "beast"

The front pump should be upgraded to the 13 vane unit.
A shift kit is in order too. The servo for the 2-4 band also needs changing.

There is a whole pastle of things needed to make a 700 a worthy gear box and these are the high points.

I believe there are some upgrades for the planet assemblies too.

The 700 "CAN" be a fairly good "little" tranny but you need to plan on spending some serious $$$$ or if your up to the task, some serious bench time and ferret out the parts from such places as ebay.

I have built a few 700R K case units with all the upgrades. They work great.

OH be sure to get a converter thats up to the task too.
There are several converter shops that build excellent units for the 700 that will handle some severe service with no problem.

You can get converters built without the lockup clutch that have heavy duty pump/turbine assemblies and are a lot tougher than the standard unit.
These require some work in the hydraulics dept. (A valve change)

best

Robyn

[BigGun J]

Choice challanged? My project is converting my Toyota Landcruiser FJ60 to a 6.2. I had always planned on going with the Toyota 5 speed. That tranny is 2grand plus adapter kit, another 1K+ The adapter kit for the 700R4 is 6 hundred. The FJ is my primary dailiy driver, fire road, hiking machine. No rock or stump jumping. Sounds like by the time I get the 700R4 built to last I could have purchased the Toyota 5 speed and kit? Wouldn't have to fab a cross member ether. I have always had sticks but, sure have enjoyed driving my new to me 93 C2500 with the 4L80E. Driving the auto got me started thinking about the auto.

Before Robin's how to build a bullet proof unit information. Local shops quoted a general rebuild for about a grand. Can anyone comment on the service life, long gevity of a general rebuild? I would think its life moving my cruiser around would be easier then moving a Blazer around?

Chevy 5 speed is to close to the heater assembly and you loose the lower heating ducts.

Thanks, Jim

[wade-ve7trw]

check out bowtie overdrive.com to get a good picture on the little tranny and what can be done to one. I just replaced the one in my 85 k1500 with a stage three extreme. The original one that came with the truck was a standard 700r4 with only 5k on it from last rebuild and i wanted something a little stronger. If you do go with one and need it rebuilt ask the shop to put in a corvette pack, this will give you a nice tranny that is beefer than stock and fairly respectable for performance.