I am looking for/at C-10 pickups and I found one with a 400 overdrive. I read the text carefully and it did have an overdrive and not an additional box added behind. So I looked on the web blogs for trans info. A regular 400 is called a 3L600 (?) and the overdrive version is called a 4L800. Is this right? Is this a precursor to the 700R4? Is the 400 case the same with each form? Is the case longer? (I would think so.) I would think this would be a much simpler overdrive swap than the 700R4 if the truck has the 3 speed 400 in it. Opens possibilities for my search. What do you think guys?
This stuff is complicated, eh? The 4L80E is the overdrive version of the TH400. I think they might have called the TH400 the 3L80 at one time, but it's always been the TH400 to most of us. The 4L80E is indeed longer than the TH400, the extra length is at the back of the bellhousing area, kind of the middle of the transmission. This is where they added the extra planetary gearset and clutch to get overdrive. The TH400 was never computer controlled, the 4L80E were all computer controlled, so swapping one in pretty much requires that you add electronics. The 4L60 is the modern name for the 700R4, while the 4L60E is the computer controlled version of it. No computer needed for the 700R4. Without pictures of the transmission in question, we can only guess what it really is.
Thanx, Squirrel! The truck in question is a 68 and the trans is the original one, so no computer. Maybe it is a 7004 but the ad sez 400 w/overdrive. Guess I better call him.
Never ever heard of a 400 over drive trans before the 4L80E. If its the original trans then he either doesn't know or blowing smoke.
700R4 didn't come out until 1982, according to Hemmings. I'm sure it was not available in 68. I don't believe there were any overdrive options in 68, but I could be wrong.
The 4L80E can have the valvebody set-up "brain dead" and run as a full manual valvebody if you want to either eliminate the need for an stand alone electronic controller or just want a race car vibe. No automatic upshift or downshift features at all, it's in whatever gear you shift it to at any time
I expect they might not have the shift quality of a TH400, or a computer controlled 4L80E? But that's just a guess...since there is no way to let the transmission know what the load is on it...
You are not wrong, in 68 there were no overdrive options. Most pickups had a 350TH transmission, but there were some 400 TH transmissions out there as well.
Yeah, it'll be just like any other trans with a full manual valvebody...high line pressure all the time and a very solid shift. If you lean towards being a racer, it won't bother you....if your just a street cruise guy, you'll probably find it very harsh. I just tossed the option out there, so if someone wanted it and didn't want to buy an electronics package.
The TH350 came along in 1969, so you'll only find the TH400 in Turbo Hydramatic equipped 68 trucks. But they did install the Powerglide in trucks in 68.
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