GM | Duramax Applications
Stock & performance parts for your Allison® GM | Duramax Transmission
Virtual Transmission by Xcalliber
Order by your Duramax model using our unique interactive online parts schematic!
"Five stars all the way!"
2007.5 Chevy 3500 dually EFI tunes DP and EGR Delete 485HP. I pull a large and overbuilt solar powered 37' 5th wheel across the country from Tennessee to Montanatwice a year.
My original transmission was rebuilt at 89,000 mi with a 700HP kit including a 3 clutch Torque converter, all new internal clutches, and shift kit / pump. (Local shop in VA) At 123,000 miles the Transmission started to slip and would enter limp mode if I got on it at all. Also banging into gear downshifting. I was never happy with this performance “upgrade” as it always shifted very hard. Maybe great for racing but not good for towing. The warranty was only good at that shop and I was hundreds of miles away with a brick for a transmission. Soooo...
I contacted Jeff at Xcalliber. Jeff wanted to know everything about my truck and trailer as well as how I drive it before he made any recommendation. He finally recommended a transmission build with a special gearing option that lowered my first 3 gears as well as special PTO covers that concentrate the fluid onto the #3 clutch pack. This is unique to DEFEO Manufacturing Co. (DBA Xcalliber)
1000PK-RED-G4-R (6320942066) - 1000PK XCALLIBER - RED PERFORMANCE SERIES ALLISON TRANSMISSION (6 SPEED) LBZ/LMM THIS LBZ/LMM RED UNIT BUILT TO ALLISON S/N 6320942066 SPECIFICATIONS
P347B-X - P3 PERFORMANCE KIT with TCM Flashing
6774322-X - PERFORMANCE C3 SIDE OILING PTO COVER SET
I had it installed at a local custom diesel truck shop in Greeneville, Tennessee. The owner of that shop commented on the trans when he received it saying “Wow! Someone went way above and beyond building this unit”. That was a nice comment as this particular shop is one of the best in Tennessee. Jeff had also sent them a three page hand written instruction set for the install to make sure everything went well.
My truck shifts like a brand new Cadillac!! Better than when it was brand new! This thing now has the gearing to pull a very heavy trailer off the line with very little throttle and at the lowest tuner setting!!I am one very happy camper!
I was blown away with the service I got from everybody at Xcalliber. They are professional, knowledgeable and very detail oriented. I would highly recommend them without reservation. Jeff Abbotts really knows his business!!
The parts have arrived and I just wanted to say how impressed I am with the quality of them all - even down to the packaging. Very professional! Thanks again for helping me and sorting out the parts list. I can’t wait to rip out the box and start rebuilding it.
Thanks again to Anthony.