Np231 doubler build. Cast in aluminum, the case should have a tag on the back saying New Process Gear (or New Venture Gear), Model 231. This DIY video should make your gears spin. 11, 10. Will fit with any 231 case and any input 231 shaft. Feb 2, 2022 · Np231 Dana 300 doubler 231 crawl box made by 4x4 machine/DD machine (Duffy) The np231 has NP241 guts, 6 pinion planetary with 27 spline input. Using some left over parts to build a DIY 231 doubler box @AttwoodsGarage Facebook Page:https://www. . Sep 8, 2006 · Are you looking to put another NP231 in front of the 231 doubler? You won't stand a chance of fitting two NP231's in there. 11 gears. 1:1 np207 to np207= 6. After installing it doesn't seem to make any difference. 5 Sterling stock 4. There were no instructions with the kit so I followed these two videos when doing the build. I planned on keeping the cables and shifter but all brackets needed come with. 0 liter 5spd. Aug 21, 2014 · I have to build a Crawler that performs on a budget. i also have access to an np208 and 205 case. Aug 12, 2015 · FrogFab is now manufactering HD doubler kit for jeep or buggy. Just have to cut your 2. 6061-t6 aluminum adapter plates. 00 NP231 Doubler crawl box adapter with clocking ring for your Jeep Wrangler TJ,YJ, or Cherokee XJ Part Number: FS-NP-231 Availability: 1 Week Lead Time We would like to show you a description here but the site won’t allow us. 4l that replaced the 2. Duane Yes that kit converts a 231 into a low range box. I have 2 np231’s and can get a 300 but looking for info from those that have done it. This is not a simple mod but it aint a real hard one either. Jul 15, 2004 · 4) This doubler will give you a low-low of np231 to np231= 7. com/profile. Like my 203 does. The NP231 features shift on-the-fly 4hi, a good lo range, and massive aftermarket support. I have had this for about 10 years, originally had a 23 spline input and was Nov 23, 2023 · Question for all the crawlers? My build is 4. The NP231 is a medium duty part-time transfer case. Np231 to Dana 300 DIY doubler kit For using the front planetary of a np231 to make a doubler t-case front of a Dana300 or 231/241 case that have a 23spline input May 19, 2024 · Hello, I built and installed an NP231 doubler kit in my truck. If you go with a D300 behind the doubler you might stand a chance. At the time of this video the doubler kit cost $485 and the install isn’t very challenging. I'm planning on running one in my XJ but I'm thinking of running a 4:1 in the 231 and the stock ratio in the Dana 300, it is recommend but not necessary to build a rear crossmember to support the assembly rather then relying the transmission extension housing and trans mount to support everything. gonna do 37 treps stickies, tons, and trying to figure if doubler is cheaper than regearing? Jun 24, 2008 · Here is the current setup: 86 XJ with the 3. I got the kit from Froelich Suspension. Starting out with a 1988 Comanche 4. Np231 to GM Np205 DIY doubler kit For using the front planetary of a np231 to make a doubler t-case front of a Gm Np205 case that have a 32spline input and 6 bolt front bolt patern Included in the kit - Np205 clocking ring - Np231 rear plate - Np231 side plate - New np231 shift rail - HD new chromoly coupler shaft - All hardware nedded Feb 6, 2012 · im in the start of making some np231 doubler kits, and was wondering if anyone might be interested in purchasing one. IIRC 2 people I know that did that with a 300 eventually killed the 300 and upgraded and killed and upgraded. 4:1 np207 to np231= 7. What I am getting (for free): NP203 from NP231 Doubler Adapter 0 Review (s) Write a Review Your Price: $485. 8:1 slap a 4:1 in one of the puppys and it gets crazy low. New versions of the NP231 are referred to as NVG231 or NV231 which stands for New Venture Gear. 4 low still feels like its the stock gearing even when both cases are (allegedly) in low gear. Come will complete head threated HD output shaft that replace the dana300 input shaft. Here's a comparison of the length difference between a stock slip-yoke 231 and the doubler kit w/D300: Just about 19" from mounting surface to center of Feb 26, 2009 · Anyone here ever here of double an np231 t-case? i have the np231 in my truck as well as another in my yard from an s-10 blazer. 0 HO, AW4 (Raddesign shifter), NP231/DANA300 doubler (was 27 spline outputs) DS60 crhromo axles and 4. The tag on the back of the transfer case . 8l (I don't recommend doing that swap, btw) AX5 transmission NP231 from an 87 XJ, SYE installed Axles I won't mention, but the front one busted a U-joint bouncing up some rock ledges. php?id=100064599283514Instagram:ht Jan 13, 2009 · The Box4Rocks doubler is 7" longer then a 231. or a few :thumb: they are based very similar to the current np231 doubler kits out there. Dana 300 has 32 spline front and rear outputs Set up for JB fab triple stick cable shifters. includes the main plate, clocking ring with We have shown you how to rebuild NP 231 transfer cases before but we haven’t shown you that you can double them up to get the cheapest low range gear set of any t-case. facebook. Thanks 0 reactions · 1 comment 󱎖 Any tips on connecting a NP231 doubler to a Tcase? 6y · Public So im going to do a np231 doubler In this video, I start the NP231J dual transfer case doubler build for my jeep using a siezed, rusted, and muddy donor case! You'll see the full assembly and Jul 19, 2008 · The particular doubler in the OP's link specifically uses a 231 as the low range box, but they also offer a kit to use other cases as the low range box. 31 and weld the side side on it or use JB weld to fix it. We Oct 10, 2025 · Doubler setup for NP231 and 300 transfer? 4y · Public Looking for anyone who has experience with doublers for their xj. zphrku odein mdcieu dujrw lsaxal puxarg zke jbazgni nwq xpetuz