ATS Stage 4 Transmission Package 04.5-05 6.6L GM Duramax LLY
SKU: 53819281399

ATS Stage 4 Transmission Package 04.5-05 6.6L GM Duramax LLY

Sale price$3860.99 Regular price$4289.99
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Description

ATS Stage 4 Transmission Package 04.5-05 6.6L GM Duramax LLYThe Allison 1000 has no doubt proven itself since its mating in 2001 behind the first Duramax equipped GM trucks. Its longevity, even when pushed with moderately heavy loads and higher horsepower have put it at the forefront of transmissions until recently. However, as miles and horsepower accumulate, these transmissions will find their failure points, and ATS has the cure to ensure your horsepower is getting to the ground efficiently. By increasing

The Allison 1000 has no doubt proven itself since its mating in 2001 behind the first Duramax equipped GM trucks. Its longevity, even when pushed with moderately heavy loads and higher horsepower have put it at the forefront of transmissions until recently. However, as miles and horsepower accumulate, these transmissions will find their failure points, and ATS has the cure to ensure your horsepower is getting to the ground efficiently.

By increasing the capability of the torque converter, clutch surface area, and line pressure, the transmission can hold 200% more torque than stock. The result is a setup strong enough to handle aftermarket fueling, turbo(s), and tuning, yet is still smooth enough to tow and daily drive with.

ATS Extreme Allison Packages include proprietary modifications to the drums and pistons. ATS has found these modifications necessary when power goes over 700hp at the tires. In addition, the pump is also modified more extensively for increased line pressure. When coupled with the Co-Pilot (standard on all Extreme Packages), line pressure in excess of 300 PSI is achieved - which is needed to prevent clutch slippage.

The Stage 4 features the addition of the ATS Co-Pilot Transmission Controller. The controller dynamically raises line pressure electronically, for additional clamping force on the clutch packs. This prevents slip under high horsepower / high torque situations, such as drag racing, sled pulling or low-speed trailer towing. Shift firmness can be adjusted with the push of a button, so the driver can adjust shift feel in a matter of seconds. The Co-Pilot is designed for trucks at any power level, but becomes crucial at 600+ hp at the tires.

SHIPPING POLICY - Due to the size and weight of transmissions, they cannot be shipped through traditional couriers, such as UPS, FedEx, USPS, etc. and MUST be shipped via truck freight. We do not offer free shipping on transmissions, however, we do offer a very competitive rate charged at checkout checkout. Once your core transmission is ready for pick up, you just need to give us a call or send us an e-mail with your original order number and the core tag on the transmission, and we can supply you with a quote on the return shipping as that is not covered in the original shipping cost. Otherwise, we give you the option to coordinate the return shipping on your own and independently pay your courier of choice. As always, if you have any questions, give us a call or send us an e-mail.

ATS GM 6.6L Duramax 4WD Allison LCT1000 Transmission Package Stage Build Comparison

Stage 1 Stage 2 Stage 3 Stage 4 Stage 5 Stage 6
Horsepower Rating 550 hp 650 hp 750 hp 850 hp 950 hp 1050 hp
ATS Allison LCT1000 Transmission
Five-Star® Torque Converter
Deep Pan Transmission Pan
Co-Pilot® Transmission Controller
ATS Billet Input Shaft
ATS Billet Intermediate Shaft
ATS Billet Output Shaft
Billet P2 Carrier, C2 Hub, P1 Sungear

ATS GM 6.6L Duramax 2WD Allison LCT1000 Transmission Package Stage Build Comparison

Stage 1 Stage 2 Stage 3 Stage 4 Stage 5
Horsepower Rating 550 hp 650 hp 750 hp 850 hp 950 hp
ATS Allison LCT1000 Transmission
Five-Star® Torque Converter
Deep Pan Transmission Pan
Co-Pilot® Transmission Controller
ATS Billet Input Shaft
ATS Billet Intermediate Shaft
Billet P2 Carrier, C2 Hub, P1 Sungear
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 53819281399

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Bly
Boise, US
★★★★★ 5
New Favorite Desk Chair
This chair is exactly what I was looking for! It is simple to put together, very sturdy and very comfortable. I typically tend to sit criss cross while at my desk and I can do that very comfortably with it. Im a bigger girlie so a chair that can hold weight or deal with me shifting positions was very important to me.
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Reviewed in the United States on May 25, 2026
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Stacy
New York, US
★★★★★ 4
Comfortable chair
Color: Cream, Size: PU Leather(No Wheels)
Ordered this chair for my daughter for Christmas. It's a great chair. It's very comfortable. She wishes it had wheels. I didn't see a way to add wheels to this base, either. Still a good chair. You have to make sure where you put it you can spin to get out of it. Pushing it back and forth on carpet doesn't work well.
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Reviewed in the United States on March 8, 2026
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ShannaC
Bozeman, US
★★★★★ 5
Great Office Chair
I purchased this chair to replace the old one in my son's room. I really like the look and style of this chair. It was easy for me to assemble and the riser functions really good and the stability of the base is very good. I like the wide design as it has more back support and seat support.
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Reviewed in the United States on January 23, 2026
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A. Blake
Phoenix, US
★★★★★ 5
Comfortable, Stylish, and Great for Casual Seating
The OLIXIS Criss Cross Legged Chair is a really nice option if you prefer sitting cross-legged or want a wider, more relaxed seating style compared to a traditional office chair. The armless design and wide seat make it easy to shift positions throughout the day without feeling restricted. Comfort-wise, the padding is decent and supportive for short to moderate sitting sessions. The adjustable height and swivel function work smoothly, and it’s easy to find a comfortable position whether you’re working at a desk, doing makeup, or just using it casually in a bedroom or home office setup. The minimalist look is also a plus—it blends well with modern decor and doesn’t take up as much visual space as bulky office chairs. Assembly was fairly straightforward and didn’t take long. One thing to note is that since it has no wheels, it’s not ideal if you need to move around your workspace frequently. Also, while it’s comfortable, it may not be the best choice for long, full workdays compared to a high-back ergonomic chair with more lumbar support. Overall, this is a stylish and functional chair that works great for light office use, studying, or casual seating—especially if you like the criss-cross sitting position.
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Reviewed in the United States on April 29, 2026
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Steven J.
Alexandria, US
★★★★★ 5
Absolutely LOVEEE
I loooove this chair. I work from home and it is so comfortable to sit in any position. It is great for sitting criss cross but you can also sit normal or on your knees. Very stable and easy to put together. Great quality
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Reviewed in the United States on April 21, 2026

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