Adapting the

Borg Warner T18 & T19 Transmissions

to the

Dana Spicer Models 18 & 20 Transfer Cases

Adapter kit for T18 & T19 to Jeep Dana transfer cases

Kit 188, adapting Ford T18 & T19 transmissions to Jeep Dana 18 & 20 transfer cases

Our Ford Borg-Warner T18 & T19 to Dana 18 & Dana 20 conversion makes for a strong, refined, compact geartrain assembly for broad use in severe terrain or refined roads. It is one of the most persistently popular manual shift transmission conversions into Jeeps, providing a very compact geartrain, an excellent crawling gear, compatibility with several engines, and simple installation.

The Novak T18 / T19 to Jeep transfer cases adapter is compact at only 1" long for a combined transmission and adapter length of 12.9". The adapter itself is of 6061-T6 aluminum alloy.

The new Novak manufactured 6 or-10 spline output shaft is machined from premium alloy steel and hardened for maximum strength and longevity. It is ready to be installed in your Borg-Warner transmission and then the Dana 18 or 20 input gear attaches directly to it.

Kit contents:

  • Adpter plate
  • Transmission mainshaft, 6 or 10 spline output
  • Seal sleeve spacer
  • Seal
  • Gaskets
  • Fastening hardware
  • Instructions

Applications & Compatibility

Compatible Transmissions

Any Ford version and year of the Borg Warner T18 and T19 can be adapted to these transfer cases. There are no advantages between the 2wd vs 4wd versions of this transmission.

Mainshaft replacement is largely straightforward. Good work is within easy reach of the careful home mechanic and instructions are included. We also recommend our basic gasket & seal kit, or this is a good time for a more thorough master rebuild and update of the transmission. An option is one of our complete Novak remanufactured and upgraded transmission packages. The advantage of a superior, professionally built transmission, tested and ready to bolt in delivered to you is definitely worthy of consideration.

Transfer Case Versions

All Jeep models of the Dana Spicer 18 and Dana Spicer 20 transfer cases are compatible with this adapter assembly. IH versions of these transfer cases are also compatible. The correct input bore and spline count must be observed. This adapter is not suitable for the Ford Bronco transfer case as it is of an entirely different design in attachment and drop.

Transfer Case Bore Size


The diameter of the transfer case center input locating bore will be either 3-5/32" or 4".

  • Most Dana 18's have a 3-5/32" bore, including those found against the T84, T90, T89 or T98.
  • Some Dana 18's have a 4" bore, including those found against the T86 & T14 transmissions (Buick V6 engines), 1966-1971.
  • All Dana 20's have a 4" bore, regardless of the transmission they were joined to.

Compatibe Jeeps

This kit is compatible with any Jeeps in which the Dana 18 and 20 were available, and most thereafter. This is one of our shortest 4-speed combinations and they fit nicely into the tunnel of most Jeeps, though early flat fenders may require some sheet metal modifications.

Compatible Engines

Any engine that can be made to work with the T18 or T19 will work with this conversion. They include:

Ford and AMC engines are the two most natural and recommended choices for this transmission.

Related Products

Urethane Rear Mount for Crossmember
T18 Parts
T18 Shifter Stick
1976-1986 Jeep floor tunnel cover
Billet PTO Cover
Dana 18 & 20 Rebuild Kit
Billet aluminum Dana transfer case pan
Dana 18 Billet PTO Cover
Dana 18 & 20 Input Gears
Dana 20 billet rear bearing cap
TurnKey T18 Transmission Package

Installation Requirements


The transmission shaft installation takes more specialized tools, heavy snap ring pliers, a press to remove and replace bearings, etc. Normal mechanics tools are required for the balance of the installation.

Transfer Case Shifter Considerations

T18 shifter clearance grinding
Marking and grinding the profile of the Dana 18 shifter footprint on a T19 case.

The T18 usually has cast iron bosses on the rear passenger side portion of the transmission case. These often need to be ground off in order to clear many factory Dana 18 & 20 shifter assemblies. In some situations with Dana 18's, the transfer case shifter mount needs to be ground for clearance as well. This is neither fun nor convenient, but is usually far outweighed by the T18's advantages.

Engines & Engine Mounting

Engine placement in these Jeeps should consider the following points:

  • Left-right offset location is similar to factory at ~1-1/4" to the driver's side
  • Avoid installing the engine too low (axle clearance and other issues)
  • Avoid installing the engine too high (transmission tunnel interference, etc.)
  • Set your engine to 4-7 degrees of tilt rearwards, like the factory engine & powertrain
  • It is usually best that Chevy and Gen III+ V8 engines install approximately 3" further forward, using the back of the engine block face as the datum
  • When mocking up your engine installation location, pay special attention to radiator and fan clearance.
  • Firewall modifications are not expected.

Since Jeeps featuring the T18 transmission are "high-hood", clearance for classic Small Block and high Vortec (truck style) intakes and accessories is not a problem.

GM Engine Mounts for JeepsNovak engine mounts are available to ease the installation of your engine.

Novak's engine mounts, feature vibration dampening, superior strength and useful adjustability - adjustable even after the engine is installed. The design, strength, and affordability of our mounts are second to none.


Driveshaft length changes may be required. Chevy engines (with their rear distributors) can install around 3" further forward than AMC engines. It is also recommended that LS family engines be installed 3" further forward than the factory block (using the back face of the block as the datum point) for exhaust clearance, firewall access, etc.

Some installers, concerned about the expense of new or modified driveshafts, attempt to let the existing driveshafts dictate engine, transmission and transfer case location, often to the detriment of the project. Our recommendation is to prioritize the correct position of drivetrain components over saving a few dollars which is usually regretted in the long run with compromised positioning.

Jeeps that require extensive travel or specialty-built driveshafts have this option available through several fabricators across the nation. These are normally specified after placement of the new transmission and measured at vehicle ride height. As the rear driveline gets shorter, it is often advantageous to us a Double Cardan or “CV style” rear shaft with the correct geometry at the axle to minimize vibrations and possible binding.


Use of factory axles is completely acceptable with this conversion. Axle upgrades are not necessary, but they may be chosen for reasons external to this transmission upgrade.

Also See