This is basic information for the DIY type person.

First, let me make sure you understand that the 700/4L60 transmissions are

METRIC units!

The threads and threaded holes are all metric in this transmission.

Pan bolts are 8mm x 1.25

Shift linkage lever & Converter to flywheel are 10mm x 1.5

Valve body, TV cable & speedo are 6mm x 1.0

Trans mount & tail housing holes are 10mm x 1.5

American (US) threads are "not close" like some people think. Use the correct nuts & bolts!   When you buy a tranz from a rebuilder or wrecking yard ask for all the needed bolts.

Here are some pics of a 700r4/4L60 transmission to help you folks identify this trans when out looking for a unit to buy.

main case

This is the passenger side of the trans main case.

Notice the casting line that is shaped like a "rainbow". It flows through the upper cooling line fitting. This is a good indication that you have a 700/4L60 trans that is new enough to have the good parts in it.

1988 case

Here is a 1988 700 case. Notice the pressure taps with plugs in them. These plugs help ID the trans as earlier than 1989. I have been "told" that the removal of these pressure taps was a "running" change which means that some 1989 cases may have the taps.

Notice the "lack" of pressure taps on this case. This is a 1989 case.

700r4 case

Please notice the flat area near the rear of the pan rail.

close view pass side

This close up view shows the small flat pad area on the right rear of the pan rail area.
Stamped in this area is a row of numbers and letters. The "first" number is a very reliable number of the year of manufacture. 1982 was the first year of a 700, but the number "9" was used for some reason. After that GM used matching numbers for the year of manufacture. A "3" would be a 1983 unit , etc.

There are more numbers and letters stamped into this area after the first number that I will not explain here since it is not necessary to find the year of the trans.

Now it gets a little difficult. In 1989 GM removed the pressure taps from the passenger side of the trans. So a "0" for the first number on the pad area with no pressure taps on the pass side indicates a 1990 unit, not a 1980 unit.

If the 700 you are looking at has a pad area that has been ground smooth, it may be from the unit being a factory rebuilt unit at one time. A tag is usually attatched to the trans case by the authorized rebuilder. This tag may or may not contain correct year info. Sometimes I have seen a year of rebuild ( ie:1989) but the case is an earlier year. This is something you find out when the pan is removed!

This picture shows a 1999 4l60E tranny. Notice that the case is 3 pieces. The bell housing unbolts too!

About 2 inches behind the ROUND 2 - 4 servo is the connector for the PCM.

99 4L60E

The links below provide additional info on the 700/4L60 trans.

700R4 problem areas

Trans case measurements

Valvebody bolt warning

700R4 electronic to cable speedo info.

Sumner's 700/4L60 Tech Info page

Lockup wiring

some tips

Driveshaft warning

Filter warning

Pump stuff

Send your questions to

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