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10 speed Allison Transmission

Double Dkar

By Double Dkar
in 6.6L Duramax Diesel (L5P)

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Lamar New Member

Lamar

Posted
Posted

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?

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ApertureX
ApertureX

The transmission for the HD's was co-developed by GM and Allison (built to Allison specs) but it is built by GM. It says Allison because it meets Allison specs and they passed their testing. Therefore

TXGREEK
TXGREEK

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

powerhaulic
powerhaulic

Mine is shifting perfectly. As for the off-road fuel, it has red dye to identify it. It is exactly the same fuel just has the red dye to identify off highway and the road taxes have not been paid

Teach Enthusiast

Teach

Posted
Posted
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 New Member

Lamar

Posted
Posted

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 Enthusiast

Teach

Posted
Posted

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

dlockwood26 Enthusiast

dlockwood26

Posted
Posted
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. 

powerhaulic Enthusiast

powerhaulic

Posted
Posted

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 Enthusiast

moonracer364

Posted
Posted

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 Enthusiast

CRApex

Posted
Posted

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 Senior Enthusiast

newdude

Posted
Posted
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

dlockwood26 Enthusiast

dlockwood26

Posted
Posted

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. 

  • 3 weeks later...
moonracer364 Enthusiast

moonracer364

Posted
Posted

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.

powerhaulic Enthusiast

powerhaulic

Posted
Posted

We tow 17k, just completed a 1300mi tow have nothing bad to say about towing with this truck.

Mine was built end of July.

  • 3 weeks later...
Lfod1836 Enthusiast

Lfod1836

Posted
Posted
On 10/15/2019 at 8:14 AM, CRApex said:

The only complaint I have is the less than lively pedal at takeoff when driving without a trailer. 

I believe I read or saw in a video somewhere that the HD's starts out in second gear when not under load. This prevents tire spin and excessive wear.

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