700r4
 

The 700r4 transmission I recently bought has a s/n 3MD335T. 1983 Model MD, built 335th day of the year, what does the T stand for?

Re: 700r4
 

Toast...that's what it will be unless you put about 1000.00 worth of parts into it upgrading it. The first couple of years of the 700 had a lot of issues

Re: 700r4
 

Yep, '83 is probably a 27 input spline shaft. '84 and later had the 30 spline input shaft. When I got my 700R4, I looked for a late one, and got a '92 unit that I had rebuilt with good stuff and a hydraulic lock-up kit to avoid the need for an electric solenoid. Frankly, it might not be worth using an early 700R4 depending on the application and horsepower.

Re: 700r4
 

In 1987 GM made a huge upgrade to the 700R4/4L60.
The GM book, with the changes made in 87, is thicker than the factory GM rebuild manual.
I absolutely would recommend to anyone using the early analog 700R4/4L60's purchase one built between 1987 and 1992. KWMech's advice is good.

In 1993 GM went to computerized controls, this is identified as a 4L60E and can be a 4L65E or a 4L70E. The "E" identifies it as an electronic unit.
These are typically the transmission used in the LS conversions as the ECM will run the transmission and the engine controls.

Re: 700r4
 

This may help?

Re: 700r4
 

What does " auxillary style " mean?

Re: 700r4
 

Auxiliary vs Non-Auxiliary Automatic Transmission
https://www.youtube.com/watch?v=4TNgZ4hbwwQ

He does a better job than I can in a text.

Re: 700r4
 

OP-where did you get it from? Perhaps it has been upgraded. My '83 K20 the original transmission went close to 80k miles before it ate the pump. It was my DD then. Pulling trailers, loaded- not particularly gentle with it. The GM dealer put a pump and a torque converter in it about 1994 and it went more, I don't remember how far. It died again about 1997 and it got a GM reman which I should have done in the first place.

But as mentioned above you absolutely want the '87 up upgrades done or you will likely have issues sooner than later.

Re: 700r4
 

That was very informative, thanks.

Re: 700r4
 

subbed good info here thank you Accelo...I got to see what year mine are