12th Nov 2013, 14:39
GM eventually came out with a 4-speed evolution of the THM-400 in the 1990s, called the 4L80, but it was only used in heavy duty pickups with diesel or the 454 Vortec.
These heavy duty transmissions wouldn't have worked so well with small-block V8s, as they need a lot of power to operate and are very heavy. But the 4L80 was probably the heaviest duty automatic transmission built by any of the Big Three during its lifespan.
3rd Nov 2013, 13:44
The 200 metric 3-speed and its variants were truly piles of junk; anything bigger than a Buick V6 would rip it to shreds at a young age.
It's too bad GM couldn't come out with a 4-speed version of the 400 back then, it is essentially the same size as the 200R4. Back then they were so concerned with making every little pound and drop of fuel count.
The 200R4 was not the greatest transmission in the world, but they are not that bad. They get a bad rap because some people ignore or do not recognize the simple maintenance issues that can turn into major problems if you let them go too long. Others simply did not know how to drive the early 4 speed automatic transmissions back in the day, and still don't today. Didn't matter if it was Ford, GM, or Chrysler.
The 200R4 was not very smooth and the lockup clutch was downright annoying if you had tall gears like 2.41 or 2.73, that I will give you. On Ford's AOD I am unable to even notice the clutch, even on units that are beginning to wear out.
A common problem was the lockup clutch solenoid going out on the 200R4, a very easy fix, but you have to drop the pan to do it. This would ironically trigger the "Check Engine" or "Service Engine Soon" light of all things, since the computer would sense the car not operating at peak efficiency. The transmission triggered a fault if the converter clutch was unable to operate after engine warm up. When the solenoid fails, it will either not operate at all, or operate at too low of a speed, causing poor acceleration and sometimes stalling the car when you come to a stop. GM transmissions were far more prone to this problem, but I've seen a few Ford and Chryslers do it too.
Old, dirty coolant is just as bad for a transmission as it is for an engine. Some people never realize that almost all transmissions have cooler lines running right to the radiator.
Others simply never gave changing transmission fluid a thought, and the 1980's is when seeing cars log well over 100,000 miles became a lot more common. Oil doesn't last forever.
It also says right in the owners manual not to drive up steep hills in 4th gear. It also says to lock the transmission into a lower gear if it keeps shifting up hills. I can't count the number of people I saw back then and even today that simply think they can leave it in 4th gear no matter what, just because it's an automatic. Burn up the transmission going up hill and the brakes going down, then blame the car when they both burn up.
The 200R4 can be rebuilt to handle as much torque as the turbo 400, and the overdrive 4th gear comes in handy if you ever want to take a gas guzzling hot rod with 4.11 gears down the interstate. It is becoming just as sought after as the 400 for that very reason. There are a lot of heavy duty rebuild kits now available for it, and some people have put them behind big blocks or modified motors putting out over 700 pounds of torque. The key is to get a professional rebuild done, not one from the old farmer or middle age redneck missing half of his teeth. Most shade tree mechanics are going to tell you that the 200r4 are all junk, but a lot of them are looking through their rose colored glasses and still think it's 1982.