Heads up gang!

We have a request for a 4:1 reduction drive to fit a 250 hp. Airboat engine utilizing the gear set as installed in a Rubican transfer case.

We are in need of information that describes the gear sets, case manufacture, specific model number, and drawings, etc.

If you have ANY information or can direct our attention to a source please let us know as this might lead to an adaptable gear box for a remote pilotless aircraft involving a DARPA contract.

We will be pleased to keep one and all informed of our progress in this matter.

Happy thanksgiving!

Milo D. Burroughs,


Here  is what I have so far. I think you woll need to buy one to get the dimensions.

Paul Lamar

The stock NP231 transfer case is 2.72:1.  The NP241OR is the version shipped in the Wrangler Rubicon, and it has the 4:1 low.  Here’s an article over at Novak on the one you’re looking for.

http://www.novak-adapt.com/knowledge/transfer-cases/np241or/

Stock NP231s are easy and cheap ($100) to find.  NP241ORs (with the 4:1 planetaries) are a lot pricier, although occasionally people swap them out for an Atlas and sell them.  They tend to run about 10 times as much on Craigslist. I’ve looked around on the web and not yet found an NP241OR planetary set for sale separately.  They’re probably available from Chrysler.

Dave Klingler


The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove  you.  ACRE NL web
site. http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas
Copyright 1998-2016 All world wide rights reserved.