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Early Model TH-700R4 Automatic Transmission Basics..

The early model 700R4 transmissions were produced until 1992 in trucks and 1993 in cars. The basic unit remained the same, however they made several modifications to the earliest models from 1982 to 1985 to cure fairly minor issues that many newer products present in their first years. As much testing and research as the auto companies do, there are always bugs that crop up that need working out in the first publicly issued models.

Compared to Ford’s first automatic overdrive transmission, known as the AOD (automatic overdrive transmission), it was a masterpiece. Some of the basic updates included a larger input shaft to handle more power and torque, particularly in the trucks. An item called a ‘sprag clutch‘ (this is a one way metal roller clutch we will discuss next time) was updated several times for the same reason, more holding power. Other than adding more clutch plates(we will discuss clutch plates soon also) in the heavier cars and having several minor updates to the TCC lockup circuit, the 700R4 remained much the same until it was fazed out for the 4L60E.

The major difference between a 700R4(4L60) and a 4L60E is that the 700R4 is fully hydraulic, and the 4L60E is a computerized operated transmission with many electrical components doing the work.
The only electrical items in the 700R4 were the TCC Lock Up solenoid and the TCC pressure switches if applicable to the vehicle. With the appropriate updates even the electrical features can be eliminated.

When I say fully hydraulic, I mean this transmission is not a sophisticated computerized automatic transmission. Where a computerized transmission gets a signal to shift by the computer and several inputs such as the VSS and a series of electrical signals, the 700R4 uses a TV(throttle velocity) cable and a governor only.

A TV cable is the main source of ‘when to shift’ up the gears or down-shift for passing. It goes directly from the transmission to the throttle assembly, which makes it effectively hooked to the gas pedal. So, when you push the gas pedal harder, it shifts later, if you need to pass and ‘floor it’, then it will down-shift. The governor has a large part to play as well, we will cover governors in a future article by itself.

As far as I’m concerned this is one of the best automatic transmission ever. It is strong and can be updated for many uses, as in, for hot rods, extra heavy commercial work and when prepared properly for a particular application is versatile beyond imagination. My 1988 GMC pickup, which I bought new has a 700R4 in it that is fully updated with an auxiliary transmission cooler. Still works great. Of course I keep it well maintained, which is my secret to long life, preventive maintenance rules.

Understanding that the last production models were in 1993, the availability of them in a good used condition is limited. If a used transmission were to be needed, my money would be on GotTransmissions.com to find a good low mileage unit. Fortunately, the 700 is a highly rebuild-able candidate, and with the right updates makes it a very desire-able choice. My strategy for replacing a broken 700R4 would start with a call to the knowledgable people at GotTransmissions.com at 866-320-1182 and start asking questions. These people are experts at listening to you and will have a solution that fits your best interest at an affordable price.

Lastly, stay tuned to our GotTransmissions.com Blog for free and learn more about transmissions in general and the 700R4 in detail. The information provided is to educate you, remember, an educated consumer always makes a better decision.

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