Complete TH400 Transmission Package

The TH400 is an automatic shift, three-speed, longitudinally positioned transmission. It is widely regarded to be a supremely durable and legendary transmission. More in-depth information is here.



Every transmission gets carefully disassembled and is deep-cleaned and inspected before assembly. New clutches, seals, bushings, bearings, and gaskets are assembled to specs that exceed OEM V8 levels. LubeGuard additive is included for longevity and shift quality. A drain plug is installed to allow easier maintenance and fluid/filter changes and every Novak-built TH400 gets a recalibrated valve body and a reconfigured governer.

One great advantage is that we will install the appropriate Novak transfer case adapter and output shaft during the build. This saves you having to open up the transmission to install the output shaft or paying to have it done. That along with our package discounted price, saves you time, money and potential problems. Transmission to engine adapters (if necessary) are available and in addition to the pricing as listed below. Please inquire.

Prices below are for GM versions of the TH400.

AMC TH400 version, add $290.
Buick TH400 version, add $90.

For customers requiring the rarer 6" 4wd, 32 spline output shaft, add $212.50.

Applications & Compatibility

Factory Style Build vs. Adapted Build

Our factory style builds are OEM style replacement transmissions using the applicable GM output shaft, but that may require the use of the vehicle owner's original tailhousing (either 2wd or 4wd) to complete the installation.

Adapted builds are designed primarily for installation into Jeep vehicles and include the installed aftermarket Novak output shaft, adapter kit and urethane crossmember rear mount, as indicated for the customer's scenario.

All levels below include a torque converter as described for those levels.

th350_103_adapterTransfer Case Adaptability

your TH400 can be ordered ready to join (or joined) to the following Jeep transfer cases:

We can do a full rebuild of your transfer case if you ship it to us. Many upgrades components are available. It will be pre-installed to the transmission and ready to install in your Jeep.

Level I, $1950. ($2580., adapted to Dana 18 / 20. $2550., adapted to Dana 300 / NP)
Our "Stock Plus" transmission that meets or exceeds the factory original version integrating a few key improvements over the originals.

  • Built to V8 specifications
  • TransGo shift kit for strength and improved shift quality
  • OEM spec clutches & bands
  • New vacuum modulator
  • Rebuilt OEM quality torque converter, including bolts.
  • New dipstick & tube
  • New torque converter bottom cover

Level II, $2490. ($3020., adapted to Dana 18 / 20. $2990., adapted to Dana 300 / NP)
Addresses key areas that can be improved in the original design for higher quality shifts, better longevity and more power handling capability.

  • Transgo Shift Reprogramming Kit (will hold lower gears at any RPM when that gear is selected)
  • Alto Red Eagle clutch discs and front band
  • HD 34 element intermediate sprag, replacing the roller clutch
  • Heavy duty, furnace brazed torque converter.
  • Heavy duty, rear band

Level III, $2890. ($3420., adapted to Dana 18 / 20. $3390., adapted to Dana 300 / NP)
Our "all-out" transmission addressing even more subtle areas needing improvements. Additional time consuming steps are taken to assure maximum strength and life including minimizing clearances and other blueprinting steps. We can customize this transmission even further for specific needs including full manual control, trans. brakes, race spec converters, Kolene steels, harder race spec shifts, etc. For level III transmissions we prefer to talk with you to make sure that you get the best transmission for your application as these units can get highly specialized.

  • Includes all features of Level II, plus the following:
  • Raybestos Blue Plate Special clutches
  • Improved oiling & cooling
  • Minimized clearances (a.k.a., blueprinting)
  • Factory HD cast case
  • High performance, furnace brazed torque converter. For an upgraded stall speed converter, additional charges may apply.

th400_with_124_front_quarterEngine Compatibility

The TH400 will most commonly be installed against a GM engine please specify Chevrolet or Buick/Olds/Pontiac bolt pattern. AMC case TH400's are also available.

The Chevy TH400 may also be used with AMC I6 & V8 engine applications with our #437AMC adapter kit. If ordered with a transmission, we will install it on the transmission.

We can also integrate your TH400 into a full TurnKey powertrain package with engine, transmission, transfer case and controls all assembled, tested and ready to install in your vehicle.



your transmission package is palleted, wrapped, fully insured and ready to bolt into your application. Novak will seek the best competitive shipping rates with our extensive trucking networks. It will arrive at a location of your choosing, though we strongly recommend a business location with a dock / forklift for delivery, as residential and liftgate fees can add up to an extra $100. per delivery.

How to Order

Because of the many variations involved, we encourage you to contact us directly by phone or e-mail. We will help you put together your transmission to best fit your requirements.