Community Forums

millsrv · 02-25-2023, 08:11 AM

Now that the 10L1000 Allison Branded GM 10 speed transmission has been on the road since 2020 in the Diesel HD Pickup Line I want to hear how they are holding up. Do you own one and if so what has been your experience with it?
Thank you...

nomad bull · 03-09-2023, 10:04 AM

I have a 2021 with 25,000 miles. My trailer loaded is around 18,500 lbs. It is very smooth and so far the only issue had been a communication error between the ecm and tcm.

xc-mark · 03-16-2023, 04:42 PM

2020, 3500 DRW. 53000 miles. It tows 18,000 lb 5th wheel trailer its NEVER been hotter then 182* even on 95* days. Its got about 15,000 towing miles. My plan is to by a new truck in the next 1~2 months, same spec.

It works well with the duramax, the 2024 model claims to have more power and more low end torque.

MADP4301 · 07-20-2023, 05:13 AM

2020 drw as well with 37,xxx miles of which 50% has been towing the 19k 5th wheel. No issues so far. Ford did a decent job on the 10 speed development and I think the GM specific tweaks were robust. There are some reported issues on both but seem to be isolated. Those buying the 2023 and 2024 years should be even better since they made some more tweaks.

Durability aside, they shift really smoothly for the amount of torque they handle. Not quite ZF smooth but very close.

spock12 · 09-19-2023, 12:23 PM

I have a 2021 GMC 3500 DRW with 63,000 miles sitting in the shop but that’s another story. I let the dealership talk me into changing the transmission fluid at 45,000 miles because I pull a heavy fifth wheel. The technician did not install enough transmission fluid and the transmission fluid got too hot on the way home. I had to pull over, I think the transmission fluid got to 220 degrees. The transmission heated up a few times until the shop replaced the transmission fluid and I have had no problems since. Nowadays only the dealership can check the transmission fluid, there is no dipstick

xc-mark · 01-21-2024, 10:25 AM

68,000 on the truck 20% hauling a 18,000lb 5th wheel no issues. I do suggest that everyone change there ATF before 50,000 miles mine was getting dark at 51K. Factory suggested 40K on fluid change.

jb882 · 02-18-2024, 11:36 PM

I have a 2024 and im happy with it so far. My 5th wheel is 24k and I dont see trans temps much above 140 unloaded and 160 towing. Its shifts smooth and does not seem to hunt for gears.

rsbrownjr · 01-04-2025, 04:23 PM

I have a 2024 3500HD Duramax (L5P) SRW High Country with approximately 22,000 miles. All I tow is a ski boat that weighs 4K lbs, tops. And that's just a few miles each weekend to the boat launch and back. We live about 5 miles from Norris Dam here in East Tennessee. It's been in the shop now for almost 4 weeks waiting on a valve body. I'm really sad about it. I am patiently waiting for the dealership to fix it - they're waiting on the new, updated valve body. It is such a nice truck to drive.

My previous Duramax was a 2005 LLY with a 5 speed Allison 1000. I drove that for 19 years. The truck was chipped with an Edge Juice with Attitude, had a K&N Filter cold air intake (mandrel bent aluminum tube with the conical filter on the end), and a straight 5 inch exhaust with no cat and no muffler - straight 5 inch pipe out of the turbo. During the time I drove that truck I replaced the head gaskets and later had to replace the turbo. No tranny issues. It had 240K miles on it when I sold it.