10 speed Allison Transmission

Lamar · October 13, 2019

I am a new Owner of the 2020 Chevy 3500 Duramax with the 10 speed Allison. I have loved the pulling of this new truck under power. It always seems to be in the right gear. But! Downshifting has been not so great! I’ve had some real hard downshifts, so bad that I thought my fifth wheel Anderson Tripod was coming off the truck. So new buyers, keep your eye open on the web. We might be jumping into these 10 speeds a little too quickly?

Teach · October 13, 2019

1 hour ago, Lamar said:

I am a new Owner of the 2020 Chevy 3500 Duramax with the 10 speed Allison. I have loved the pulling of this new truck under power. It always seems to be in the right gear. But! Downshifting has been not so great! I’ve had some real hard downshifts, so bad that I thought my fifth wheel Anderson Tripod was coming off the truck. So new buyers, keep your eye open on the web. We might be jumping into these 10 speeds a little too quickly?

Drove one yesterday and the 10 L 1000 shifted silky smooth. Truck had a July build date.

Lamar · October 13, 2019

Mine is a June Build date. Without trailer it is smooth as can be! And driving with trailer it’s smooth too. Holding back a big heavy load about 14k pounds towing or more when downshifting is when it is starting to show some issues. I have 1000 miles on my truck and it seems this issue just started to become something new that was not there the first few hundred miles. Everyone in my truck feels it. This issue is not just me saying a little miss-shift, it’s very abrupt and concerning!

Teach · October 13, 2019

I am certain this can be addressed with TCM download when the factory releases it to the dealer

dlockwood26 · October 14, 2019

On 10/12/2019 at 8:22 PM, Teach said:

I believe what you are experiencing on the slow down is due to the 3.73 gears in the differential where as the 2020 is equipped with 3.42 gears. Big difference.

I suspect you are correct. I hadn’t thought of that. I was stuck in thinking the ten speed must be geared higher and allowing more coasting.

Teach · October 14, 2019

powerhaulic · October 15, 2019

I want my 3.73's back, loving the performance of the 10spd but think it would be better......

my '18 got better mileage towing our 17k fifth wheel, but the 2020 is better empty as you would expect.

moonracer364 · October 15, 2019

My shifting was really hard, but is getting progressively better. The first time I stopped an empty trailer it sounded and felt like it had disconnected and hit the back of the truck. I could never get it to repeat the problem after that.

I'm at 1500 miles now, I can only notice the downshift about 1/10 times now when I come to a stop.

CRApex · October 15, 2019

4900 on mine now. Shifts very smooth, with and without a trailer. Certainly feels stronger towing than my 17 did. The only complaint I have is the less than lively pedal at takeoff when driving without a trailer.

newdude · October 15, 2019

On ‎9‎/‎1‎/‎2019 at 11:54 PM, TXGREEK said:

Wonder what country they were built in. I’m sure it’s cheaper for greedy GM to build it using their 3rd world child sweat shops than Allison to build their own.

Sent from my iPhone using Tapatalk

The 10L1000 is built in the country of Toledo. Toledo, Ohio, USA to be exact. https://media.gm.com/media/us/en/gm/company_info/facilities/powertrain/toledo.html

newdude · October 15, 2019

On ‎9‎/‎4‎/‎2019 at 9:20 PM, redwngr said:

Thanks!

Are they building the 10 speed for the 1500 in Romulus?

10 speed in truck/suv appears to be Romulus. https://media.gm.com/media/us/en/gm/company_info/facilities/powertrain/romulus.html

"Allison" 10L1000 is Toledo. https://media.gm.com/media/us/en/gm/company_info/facilities/powertrain/toledo.html

dlockwood26 · October 16, 2019

One other thing I think I notice is along with the higher rear end gears contributing to coasting easier is that the transmission seems to shift to higher gears all the time when not accelerating. I am sure this helps with mpg when not towing but my 2016 LML seemed to stay in a lower gear and stayed in the power/torque band longer regardless of speed. Always around 1,300 to 1,600 rpm. Thus when letting off accelerator truck would quickly slow. Again not bad just different.

moonracer364 · October 31, 2019

I called the dealer about the hard shift from highway speed to a stop, and the service rep told me this was completely normal for this transmission. He said there was nothing they could do, and it will probably go away after a few thousand miles.

Not sure if I believe him, but maybe I'll give this truck another couple of months before I start looking at other dealers.