23 spline to 29 spline Coupler

This 23 spline to 29 spline coupler is designed to allow the use of the stronger 29 spline NP-205 transfer case (found in 5-speed trucks) behind an automatic transmission. Great for sled pullers, drag racers, or even tow rigs who have ever broken a 23 spline NP-205 input or don't want to take that chance. This coupler also allows the use of a 23 spline NP-205 (found in automatic trucks) behind a 5-speed transmission which is great for auto to manual conversions.

This coupler has been torture tested to approximately 700 horsepower in a customers truck that is used primarily for drag racing and sled pulling without a single issue!

Note: Your core charge will be refunded to you upon receiving your usable 23 spline coupler. 

Note: This coupler measures 2.5" outside diameter, while the stock coupler measures 2.125" OD. Most transmissions have a large enough opening in the case where the original seal was installed, providing adequate clearance for the new coupler, however it has been brought to my attention that some NV4500's have an opening of less than 2.5" in the back of the case causing the new coupler not to fit. Please measure the opening around the output shaft in the transmission case of your transmission to ensure there will be adequate clearance. If you do in fact have a transmission with the smaller opening in the case contact me with the dimension and we can discuss further options.

Note: The core charge has been increased due to the fact that the 23 spline couplers are becoming harder to find and without them I can not build more 23-29 couplers.

23 spline to 29 spline Coupler
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  • Item #: 2329COUPLER
Price $175.00
Availability Out-of-Stock