Novak Conversions 4L80E to Jeep 241J Adapter Kit

4L80E to Jeep 241J Adapter Kit

Additional Images

  • 4L81-AL-23 transfer case adapter kit
  • 4l80 to 241J transfercase adapter
  • 4l80e to jeep jk 241J LS SWAP rpmextreme
  • 4L80-OSS output speed sensor kit
Part Number: 4l81-BJ JK-241J - 4l80 LATE Tcase Input 32 spline

Available Options

Retail: $619.00 Web Price: $569.00

Product Description

We curently only stock the 4l81-BJ Kit
The Adapter

The 4L80e to Jeep transfer cases adapter is compact at only 3.0" long for a combined transmission and adapter length of 29-1/4". The adapter itself is machined of a 6061 billet aluminum alloy, featuring thick flanges and a heavy cross-section. 

The Output Speed Sensor

If your 4L80 does not have a rear output speed sensor you will need to order the OSS kit and add a reluctor ring to the inside of the transmission.

Transfer Case Clocking & Rotation Options 

Our adapter is drilled for multiple clocking locations from near-factory (20 degrees down) to near-flat (3 degrees down). However, pan clearances and front axle width may inhibit the flatter options

Rear Mount Provision 

This transfer case adapter's design is based on our Universal Series adapters that feature a modular mounting and support system. Included with the adapter kit is a steel base that is a highly configurable mounting foot, and is ready to accept our industry standard urethane isolator mount and is available for purchase below.

 

Applications & Compatibility

4l80e_transmission_drivers_sideTransmissions

All versions and years of the 4L80E can be adapted to the NP (New Process) transfer cases. Both the 2WD and 4WD versions work equally well with the correct adapter option. 

Output Shaft Speed Sensor

1991 - 1996 4L80E's should feature a speed sensor at the driver's side rear portion of the case, whether they are 2wd or 4wd applications. 1997 and later 4wd applications often omit the rear sensor as this data is available from the factory GM transfer case output shaft. **If your 4l80e does not have a vehicle speed sensor you will be required to install a sensor and its internal reluctor ring. This is best to be installed by a transmission building professional as the transmission will need to be opened up.**

Early vs Late 4L80E Oiling

In about 1997, GM changed the way the rear bushing is oiled in the 4L80E transmission. The shafts are not interchangeable and you will need to identify for sure which version you need.

  • The first design has two lube holes in the sides of the case bushing journal. Lube flows through these feeding the output shaft and forward to the planets.
  • The second design does not have the lube holes instead has a tube feeding oil from the valve body. 

 

Option I: Transmission Output Shaft Version "A" (4L81-AL-23)

The 4L81-A adapter is compatible with all versions of the 4L80E.  The new 23 spline 4L80E output shaft is machined from stock material through an extensive process ensuring maximum strength and a precise fit. The new output shaft splines directly into the OEM style input shaft of a 23 spline transfer case. The 241OR Rubicon will work with this 23 spline output option.  Disassembly of the transmission  is necessary to install a new  23 spline output shaft.

Option II: Transfer Case Input Shaft Version "B"  (4181-BJ JK 241J)

A 32 spline 4wd version of the 4L80E is ready to bolt up to our 4L81B adapter kit. Disassembly of the transmission is unnecessary as the 32 spline 4wd style output shaft (which protrudes about 3" from the rear face of the 4L80E transmission main case) is correct for this kit version.

Disassembly of the transfer case is necessary to install a new matching 32 spline NP input gear. The input gear installation is a 2-3 hour bench job and usually includes a simple gasket and seal replacement.

 

Option III: Transmission output Shaft Version 23 to 32 spline "C"  (4181-32)

Use this option if you have a transfer case with a 32 spline input. This will convert your transmission to a 32 spline output shaft.                      ** This option is not used very often **

Disassembly of the transmission  is necessary to install a new  32 spline output shaft. 

 

NP JK Transfer Cases

The adapter kit is designed for compatibility with the Jeep JK NP241J & NP241OR "RockTrac" transfer cases. Below is a summary of spline counts and lengths usually encountered. 

  • 241J - The NP241J always has 23 splines, short style input gear
  • 241OR - The RockTrac will always have a 23 spline, short style input gear. Its gear is unique and not interchangeable with any of the other versions due to the lower 4:1 ratio

** You will need a Transmission Mount listed below to mount this adapter to a crossmember **