th400 or 4l80e

[randomhero]

Another thing to think about is if you get a th400, and later decide that youwant overdrive... You can pick up a used Gearvendors overdrive unit that turns your 3 speed to a 6 speed. $1000-$1800 used, $2500 new.

HMM first I've heard of that. Does it jeopardize the integrity of the transmission?

[ff_jeff]

HMM first I've heard of that. Does it jeopardize the integrity of the transmission?

Nope. In fact they are good over 1kwhp. And only rob 1 hp per 400whp. As soon as I can afford it Thats what Im putting on my th400.

[randomhero]

Nope. In fact they are good over 1kwhp. And only rob 1 hp per 400whp. As soon as I can afford it Thats what Im putting on my th400.

I need to look into this for when my built 4l60e pops. I suppose it's technically not an overdrive though right? It doesn't actually lock the torque converter, it just has super low gearing right?

I know very little about transmissions so bear with me.

[GasGuzzler]

TCC and overdrive are two things. Overdrive spins the output shaft faster than the engine. Overdrive is obvious internal to the 60 and 80 but the Gear Vendors is a planetary 2-speed gear box that mounts to the rear of the transmission kinda like a single output transfer case. Since it has two speeds you can split each gear turning a 3-speed trans into a 6-speed (although the ratios would be so close you won't normally split all three during a race). 1st low, 1st high, 2nd low, 2nd high, 3rd low, 3rd high. The TCC is merely a clutch inside the converter that locks up to stop converter slippage.

[randomhero]

TCC and overdrive are two things. Overdrive spins the output shaft faster than the engine. Overdrive is obvious internal to the 60 and 80 but the Gear Vendors is a planetary 2-speed gear box that mounts to the rear of the transmission kinda like a single output transfer case. Since it has two speeds you can split each gear turning a 3-speed trans into a 6-speed (although the ratios would be so close you won't normally split all three during a race). 1st low, 1st high, 2nd low, 2nd high, 3rd low, 3rd high. The TCC is merely a clutch inside the converter that locks up to stop converter slippage.

You learn something new every day. I always assumed overdrive was just the torque converter lockup with super low gearing. I never bothered to think how it was able to go lower than a 1:1 ratio.

[GasGuzzler]

That's why they say 4th is 0.7:1 in a 60E...less than 1:1 (3rd gear). The new 6-speed autos don't have a direct (1:1) gear.

[goodie454]

what about the speed sensor output and the pn safety switch how would i wire those up
??

[GasGuzzler]

There is an adapter for the VSS, ask DamnYankee or mean05. There is no PRNDL switch needed...only a P/N switch for safety (mounted to an aftermarket floor shifter) unless you want the stock gear display in the info center to work.

[goodie454]

ok what you think of this setup
6.0 comp 222/224 cam th400 np205
3200 stahl transgo 400-pro shift kit and a deep pan ????

[fullthrottle]

Is the th400 and 4L80 the same t-case adapter? If not it could be more expensive for an adapter if you use the 205 on the 4L80. My 4L60 to np205 adapter was over 400 bucks from Advanced Adapters. A stock 400 to 205 would be much cheaper. That sounds like a sweet setup to me man. What year trucks this goin into?