I agree that it performs very well in my experience. One of my favorite aspects is that it seems to actively downshift to assist with braking much better than any other vehicle i have had. I would be a bigger fan if mine didnt have a leak like many others have reported at the TC or a front seal, but i concur the performance is top notch for me.

 

The "grade braking" feature is common to all the Allisons in the Duramax. Really is nice when pulling a heavy trailer in town.

 

The 5 speed Allison I had with my 8.1 L was amazing. The 10 speed Allison with my 2022 L5P is 2x better.

 

So, is the really the same as the Ford 10 speed? lol. That’s a joke.

I really like it too. It’s true that it’s always where it needs to be. I’m on my second one. First was in a 22’. Very happy with these transmissions.

 

When I bought my 2020 I thought the 10spd would be constantly hunting and shifting like some of the newer gas cars. Its not like that at all! Selects a gear and holds. Works great and towing is a pleasure. Keeps the engine right in the sweet spot of 2400-2500 RPM on hills. Not screaming but enough power to tow a house. Cruise RPM unloaded at 60mph is like 1300RPM! Just off idle! Crazy low.

Probably the best feature of the truck is the 10spd!

 

Fwiw, the little 10 speed behind the 3.0L is also an excellent combination.

 

I have been very happy with mine as well but I wish it would only use 1st gear in tow/haul like the 10L1000. And I find it needs to be sport mode to shift a smooth as the 10L1000.

 

Agree 100%. Best transmission I’ve ever experienced. Also love how cool it stays, even while towing, regularly hovering between 140° and 150°. Coming from a Ford Raptor (loved that truck in general) that grenaded its 10 speed, and watching my brothers Powerstroke, F350 Tremor’s 10 speed hover around 200° even when he’s not towing, I totally appreciate the engineering that went into this transmission.

 

Glad to hear guys. Keep posting your success stories here.
Forums do tend to magnify the negative.
Those with MY 24s, it would be nice to hear about your thoughts on the exhaust braking. Especially if you had a pre MY 20+ before.

 

Glad to hear guys. Keep posting your success stories here.
Forums do tend to magnify the negative.
Those with MY 24s, it would be nice to hear about your thoughts on the exhaust braking. Especially if you had a pre MY 20+ before.

I only have 3100km on my 2024 and only about 500km of that is towing but so far I feel the exhaust brake is similar to my 2017. Going on a 2000+km trip through the Rockies in 2 weeks with the trailer so that will be the test.

 

That exhaust brake has saved my hind quarters quite a few times. Love that feature and yes, stays cool as a cucumber when towing, even in the summer heat.
Best trans I've ever owned.

 

10 speed does tow great. Feels like it downshifts a bit too much for my liking. Just finished a round trip from Houston - Moab - Monument Valley - Houston.

The Adaptive Cruise and normal cruise use too much brake and not enough engine. Hopefully GM finds a happy medium between the two.

 

The Adaptive Cruise and normal cruise use too much brake and not enough engine.

You talking about the truck applying it is physical brake vs engine breaking? Must be a 2024 thing?

 

Had a hiccup with my trans between 7 and 8k. Warranty resolved it. Tows strong, once you get used to the exhaust brake it works well. Don't have experience with furd or dodge exhaust brakes so no comparison there from me.

Trans is smooth as butter, down shift in tow haul can be aggressive but that's not a bad thing and again once you get used to how the truck drives it's awesome and easy. After moving from a 07 dodge to this truck it is such a relaxing drive in comparison.

 

surprised it applies brakes when set to normal cruise mode. Seems dangerous. One would think there would have to be a way to dis-engage that feature.

 

One would think. Even if you decrease speed on the cruise by more than 5 mph it applies the brakes. I've been looking though the menus off an on to see if there is a setting to change.

Normal cruise does not keep the gap like the adaptive cruise. Adaptive sometimes gets confused and will brake for no reason the correct.

 

I thought adaptive cruise would be nice, but it’s a little unrefined. Even at the narrowest setting. I’ll probably save that for when I know I’m getting tired, and a little computer intervention could help. We’ve got a newer Audi as well and while it’s adaptive cruise is better than the GM version it’s still just ok.

I didn’t realize all these trucks use brakes in cruise till I fell into a YouTube rabbit watching gauntlet videos. One of their metrics was how often the trucks hit the brakes on the downhill in cruise. Ford does it, GM Does it and I think Ram did as well. Must be a new 2024 “feature”. Or earlier and I was just unaware.

 

Pretty positive my 22 doesn't do it. I'm glad it doesn't. Last thing I need is the truck applying brakes on wet or icy conditions. I'm willing to bet traction control off would prevent it but it should not be that complicated to get the truck to not brake.

 

I know my 2020 doesn't have it.

 

 

So, eating too much popcorn does give you big ears!?

 

I had a '19 before buying the '23. With the '19, I was always shutting off tow mode on flats because the 6speed would not settle into 6th gear, and the RPMs hovered around 1800. With the 10speed I set tow mode and forget it. RMPs between 1500 -1600 on flats. Exhaust brake performed great on both trucks. I have a 7500lbs travel trailer that I pulled with both trucks.

 

OK so I was towing this morning to have inspection on trailer done. As you can see in both photos, cruise engaged by the green number under the lane lines. The eyebrow over the number means adaptive cruise and since there is no vehicle emblem between the lines the cruise is not reacting to an auto in the lane. The speedometer to the left of the number means normal cruise. More than 5 MPH decrease in speed in both pictures. As you see in both pictures the truck is activating the trailer brakes, I am not using the manual control and since cruise is active I have not touched the brakes.

 

For me...I can't get past the fact that you have four hundred and three miles till empty, on less than an eight of a tank???
Is that correct, or do I need to get a stronger pair of reading glasses?

 

fuel gauge is directly under range, it's slap full. Note the white line by the F that's the reading and the line gets thinner as it goes down.

 

You would have thought turning on tow haul mode would turn that feature off. Wonder if you turn off your traction control if it would stop?

I'd be bugging the dealer about that one or calling GMC support, would consider that a safety issue. Of course they would prolly just say don't use cruise in the rain. But the thought of going down the mountain and wondering if the brakes are gonna get how running cruise is a pondering thought with what you have shown.

 

In the mountains / hills going south from Moab to Monument, I got in the habit of dropping into manual mode, killing cruise, and tap downshifting after a small brake application to activate the engine brake and it would hold speed. If it tried climbing, I'd command another down shift if it was in the safe RPM range.

 

The performance is wonderful, the reliability on a large scale is not. We've replaced far more 10 speeds in 3 years than we did 6 speeds in 20. Now the oft failed valve bodies are on yet another backorder and i was advised this week we're looking at 5 months for parts. No thanks

 

What's happening to the valve bodies? I know the rams used to have an issue where they would warp. I have seen the valve body issue popping up as more miles get put on these trucks.

 

 

$245 bag of popcorn in a movie theatre!

 

Almost liking my 10sp, it almost feels like a CVT. I do wish that the plus minus buttons on the shifter worked without dropping to the next Lever position. Would be useful for a quick downshift. Don't really like that it downshift for me when going to L nor do I like that it only limits the upper range of gears. I should be able to put it in and have it stay in 5, instead it will downshift on a descent and spin crazy high RPM in an attempt to regular speed. When I get back on the gas it just revs really high and takes forever to upshift. Does this n D or L. The logic is just stupid, driving on country roads with a lot of hills it will downshift going down then refuse to upshift until it decides I am not immediately going up a hill, often times will hold 2400 RPM a good bit. Very frustrating.

 

If you are very frustrated with it you can get an aftermarket tune, and it would command gears to be held longer.
providing you want to spend the money.

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