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Allison 10L1000 transmission
Lifetime warranty. Upfront pricing. No surprises.
The 10L1000 is the Allison 10-speed in GM's current heavy-duty pickups. Newer trucks are not immune, and a dealer back-order on parts can park a work truck for weeks.
Which vehicles have an Allison 10L1000?
- Chevrolet Silverado 2500HD and 3500HD Duramax, 2020 and newer
- GMC Sierra 2500HD and 3500HD Duramax, 2020 and newer
- Silverado and Sierra HD with the 6.6 gas engine, 2024 and newer
Signs your Allison 10L1000 is failing
- Harsh, delayed or busy shifting
- Slipping when towing
- Shudder under load
- Limp mode or a transmission warning
In 2025 GM truck owners waited weeks to months on a dealer back-order for transmission valve bodies. Henry builds his own.
Drop it off by 8, diagnosed today
Bring it in by 8 on a weekday and you have a diagnosis and a decision on your Allison 10L1000 the same day. Every time. Parts come direct from the manufacturer, usually within 24 hours, and the valve body is built here, not back-ordered.
Upfront price: call (919) 836-8820 for your Allison 10L1000 price, installed, before any work starts.
How Henry builds an Allison 10L1000
- Every known weak point upgraded. Each model has parts that are known to fail. They are upgraded on every build, for a stronger transmission than the one that came out.
- Torn down completely. Every unit comes apart on the bench, gets cleaned inside and out, and every part is measured.
- Every seal, every time. A full factory gasket and seal kit, including the internal seals most shops look at and reuse.
- A new torque converter. On every build. Not the old one cleaned up.
- Valve body built and tested here. Checked on a vacuum test machine so every valve moves the way it should.
- Worn parts go in the trash. Clutches that are starting to darken, a front pump that "still works", hard parts with wear. They do not go back in.
- Tested before it goes in. The finished unit is measured and tested on the bench, then installed, programmed and road-tested.
"When I build one, I only want to build it one time." Henry Tilton. Covered by our lifetime warranty.
Tell the builder about your truck
Send the year, make and model and what it is doing. You get a call back from the person who builds the transmissions.
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