Low 1st Gear TH-400
 

I know some people put a lower 1st gear in a TH-400 to get out of the hole faster. I understand how this would improve 60' times. Now with the lower 1st gear when you shift into 2nd you will have a larger RPM drop than you would with the standard 1st gear. Can someone explain how this will affect overall E.T.? Would the 1-2 shift pull the engine down and cancel out any gain in 60'?

I had a lower 1st gear in a TH400 the late Greg Merrick built. It was great while it lasted...BUT that planetary gearset (I believe from a TH200) is much weaker. My HFT cammed 463 did this to it.

depends on HP and converter.

Non-stock 1st ratio is a Waste of money with 400+ CID, if ya gotta upshift before the 60foot

I dont have numbers in front of me and sometimes varies by manufacturer but i believe second gear is also lower.spreading out the RPM drops its not just on 1-2 shift

Also i believe the higher quality units have 5 planet gears, Hughes stands out in my memory as a better one

When first gear is lower your second is also in my th400 and the pinions are square cut. Its makes alittle noise but not really noticed.

Coan offers many different gear ratios for the T400
Rossler offers many different gear ratios for the T400 and also the 4L80E
Scott McClay offers many different gear ratios for the TH200

Stan

I used a coan in my grandville years ago it was 5 pinion gear set and very strong! Those Tci ones are junk and weak, not sure what greg used above

Hey Tim,
Learned of these gear sets in the early 1980s and first used one on 72 GTO street/strip car. My first 11 second daily driver back then in 1985. I liked it and swore by them for 10 years or so but, as time went on, I now think it good for a heavy street car owner than does not want to use an OD trans. Otherwise, probably best not to use one on a dedicated bracket deal.
Have one today in a trans I purchased with a car. Not sure what I will use it in, maybe one of my station wagons.