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4/10/24 - Timberline will have limited fulfillment on core/turnkey kits for May. April has been filled. We have 2 spots in May, and further larger orders will likely ship in June when normall fulfillment continues. Smaller orders on 1-5 pieces shouldn't have too many hold ups. We appreciate your business and are working hard to keep up! 720-515-5933. Thanks!
4/10/24 - Timberline will have limited fulfillment on core/turnkey kits for May. April has been filled. We have 2 spots in May, and further larger orders will likely ship in June when normall fulfillment continues. Smaller orders on 1-5 pieces shouldn't have too many hold ups. We appreciate your business and are working hard to keep up! 720-515-5933. Thanks!
Timberline 4WD 4L80 Conversion Kit

4L80 4x4 Conversion Adapter Kit (no-cut)

$695.00
4x4 Housing
Description:

This is a straightforward bolt-on solution for converting your 4L80 transmission to 4x4, without the need to cut the output shaft.

To accomplish this, simply remove the 2WD extension housing, bolt up the provided OE 4x4 housing and attach our billet aluminum adapter to your compatible 241 or 261 transfer case, and the unit will bolt right up. 

This adapter serves multiple functions. Firstly, it eliminates the need to trim your 2WD output shaft. It shifts your transfer case back by an extra 3 inches, resulting in a shallower drive angle (reducing driveshaft feedback). Lastly, our adapter slightly reclocks the t-case output upwards and outwards, providing more clearance over the cross member and the transmission wiring harness plug.

Your transmission will continue to use the 32-spline output shaft commonly found in many models, spanning from 1999 to 2006 (likely applicable to other years as well). No further modifications are necessary.

We prefer the New Process 261 transfer case due to its reputation for being both the quietest and most durable option. This noise reduction aspect is particularly relevant in a van setup, where you're seated directly above the t-case, with a hole in the floor for the shifter lever. The NP261 transfer case with a 32-spline input was used in many GM half-ton through 1-ton pickups with gas engines from 1999-2006. The LD model is sufficient for most builds unless you're building a race van or towing extensively with a diesel. 

Fitment Designed for: 

Van Side - 2003-2009 Chevrolet Express 2500/3500/4500 series vans with 4L80 Transmission (4.8L, 6.0L, 6.6L). 

Note - The 4L80 transmission was used as early as 1991 and as late as 2013. We have designed this unit for the years described, but it will likely work on many applications.

Truck Side - This unit is designed to work with a standard 4L80 4x4 extension housing available here, as well as the NP261 transfer case. It may work for other models, but this is how we've designed it. 

Tools Required:

Standard hand tools, thread locker

Included:

Transmission adapter assembly, M10 hardened grade 10 studs, and top lock nuts

Construction Notes:

Machined solid billet aluminum, Grade 10 hardware

Tips / Skill Level:

1-10 (10 being most difficult) Level 2

This product may work with other model vehicles. 

Torque spec on M10 transmission case bolts and transfer case nuts is 37 Ft-lbs, use thread locker!

Tip - When installing a shift boot for your transfer case, find a heavy piece of rubber slightly larger than the hole, and cut a slit down the middle. Sandwich that between the floor of your van and your floor covering, then install your shift boot over it. This will significantly cut down on road noise and heat loss/gain. 

Shipping, Fulfillment, Taxes, Quality, and Returns
  • Shipping: Our components are carefully wrapped & packaged and shipped via UPS, USPS, or FedEx, depending on what is available. If you require a particular carrier, please contact us ahead of your purchase.  Customers in Colorado may arrange for in-person pickup within 1-2 business days of purchase. 
  • Shipping/Fulfillment time for components: We typically ship within 1-2 business days of your order and we carefully monitor our inventory. In the event that we are unable to meet that timeframe, we will contact you and arrange either a full refund or a timeframe for fulfillment agreeable to the customer. 
  • Taxes: Colorado residents must pay a sales tax of 7.5%, no sales tax is collected on out-of-state shipments currently. 
  • Quality and Returns:  We are consistently complimented on the quality of our products and the ease of installation. Fabricated components are generally hand-built here in Colorado by seasoned professionals. Replacement or aftermarket parts are only offered in high-grade options.

    If you are in any way disappointed in the components, we will issue a full refund less the cost of shipping when the product is returned within 30 days of receipt. If you decide to return any components that didn't apply to your build or you changed your mind about, a shipping +15 % restocking fee will be deducted from the refund.