Am I a dinosaur? Took a Chevy 400 Trans to the rebuilder for a refresh for yet another 32 roadster project. I had this trans rebuilt 25+ years ago and it sat in the corner all those years as a suitable project never came along. When I first started building 32's in the 70's it was my trans of choice. Maybe I'm living life nostalgic?
Still one of the best heavy duty (non overdrive) transmissions, and commonly adapted to other make engines. They're also the choice of 4000+ HP drag cars ...... but with substantial modifications and reinforcements etc.
I always liked the th350 for my cars. The 400, I felt, was over-kill for the horsepower I was dealing with.
I still have one wrapped up from around 1983, out of a stock car engine donor. A long tail from a station wagon, swapped into an Impala/Caprice. The vintage is 1974, anyone local wants it, will swap it for a case of cheap beer.
A good case where the snap ring support is not broke will cost a person around $300 for a Chevy. BOP may be more.
TH400/ST400 is my go-to transmission. Rugged, and easy to rebuild. Nail-Head pattern cases are getting a little harder to find, but still out there. I have an empty BOP case in my stock.
Got a 475 I saved out of a motorhome stashed under a bench Running a th400 with Doug Nash OD in my current ride
Me. Everything I build has an overdrive gear, sometimes two, EFI, disc brakes, AC, and a 5-channel high-wattage audio system.
Back in the early 70's I taught automatic transmission rebuilding at SIU-STC (Southern Illinois Universtiy - School of Technical Careers). The three heavy duty transmission of the time were the 727 Torqueflite, Ford C6, and the GM THM 400. By far the 400 was the best engineered of the three. The nailhead in my Model A is backed by a 400 with a 2 position stator. In my opinion (for what it's worth) the THM or ST 400 with a 2 position stator was the cream of the crop.
I'm kinda dumb. When I rebuild a tranny, I see that expanse of beautiful aluminum and can't resist the temptation to polish and clear powder coat it. Here are photos of a 200R4 and Powerglide that got polished. I polished the TH400 in the '42 Willys pickup above too but didn't get a photo of it.
The turbo 400 was the standard issue (GM) automatic drag transmission for years before the aftermarket tooled up for the Powerglide. I built my second drag car in 1977, was having a time finding a core trans so bought a running/driving 1965 Impala Super Sport with a 396/turbo 400 just for the transmission. Had the trans build sponsored so did not have much out of pocket money in it. I paid $150 for the car then sold the engine for $100, think I had the rest hauled off.
Great transmission. Went more than 1200 passes in the 9's and 10's in my avatar drag car without wearing out or breaking, feeding it 600+ ft lbs of engine torque plus the converter multiplication.
One in my 57 Vette. Had about 700 hp at one point on it before I made it a street car and changed the converter to a more street friendly stall Been in there 30 years now. These days I wish it had OD.
I was a very sick person , stage 4 cancer when the 32 arrived for me to be the care taker . I had a 70, LT1 and short tail 400 . I just wanted to take a ride in the 32 , it may well have been my last . So in went the LT1 and 400 . All worked fine , it did not shift as well as the TH350 that was in my previous 37 Chebbie . As my health and life progressed , out with the bow tie stuff in with the blue oval stuff . My Buddy put the LT1 and TH400 in an OT S10 pickup , 11.90 1st pass .
The the Chrysler 904, and 727, Ford C3, C4. C5, and C6, GM 125, 200, 350, 375, 400, and 425, are Simson designs. Simpson had 24 separate patents on the 3 speed planetary transmission. There were two general designs in use for years, the. Raveneaux and Simpson. Borg Warner predominately offered Raveneaux. Everyone else opted for the Simpson design. Much easier function and repair. Aĺl Simpson designed transmissions used an intermediate band (second gear) with the TH350 using a clutch for automatic 2nd and a band for manual second. Only the TH400 family used clutches only in all gears. The TH400 is the best of all of them in durability and smoothness of shifts as stock. I have built numerous automatic transmissions in my life and always liked the TH400 operation the best. Just so you know, I am a Ford guy an still like the The TH400 the best of all the Simpson designs
The Jalopy Journal
