School me on transmissions and "learning"

[Sin City Trail Boss]

Hello all,

 

I had my TB with the 5.3 and 6spd for a few weeks now. I am about 600 miles in so far.

 

So far I love this truck!

 

My only mild complaint is the tranny and shifting.

 

When coming to a stop, especially if its a quick stop, I get this thump as if someone tapped my rear bumper.

 

Also when taking off slowly from a stop, sometimes I feel the transmission upshifts too fast and I get this hesitation where the truck goes forward but very slowly and I have to mash the gas a bit to snap the tranny out of it.

 

So my question is, is this normal and also, how long does the "learning" process take? Have you guys noticed your truck shifting smoother after a few thousand miles on it?

 

Thanks everyone.

[HondaHawkGT]

On 7/15/2019 at 9:05 AM, Sin City Trail Boss said:

Hello all,

 

I had my TB with the 5.3 and 6spd for a few weeks now. I am about 600 miles in so far.

 

So far I love this truck!

 

My only mild complaint is the tranny and shifting.

 

When coming to a stop, especially if its a quick stop, I get this thump as if someone tapped my rear bumper.

 

Also when taking off slowly from a stop, sometimes I feel the transmission upshifts too fast and I get this hesitation where the truck goes forward but very slowly and I have to mash the gas a bit to snap the tranny out of it.

 

So my question is, is this normal and also, how long does the "learning" process take? Have you guys noticed your truck shifting smoother after a few thousand miles on it?

 

Thanks everyone.

 

It's called a "bump downshift" and it's a common issue on all modern half-ton trucks. They're keeping the torque converter clutch locked up as you slow to a stop, using your forward movement to turn the engine so that the engine doesn't have to burn fuel to keep it spinning while you're essentially coasting to a stop. It's not always a smooth. It affects GM transmissions, the Ford 10-speed, and event the Ram's ZF 8-speed. 

 

You can teach the transmission to downshift better by getting the truck up to 30 mph and just let it coast to a stop without pressing the brake. Every time it downshifts, it's trying to do it as smooth as possible and the computer "learns" or makes adapts so it performs the shifts better. That's where consistent driving is important. Some guys will drive the truck really hard and the transmission will adapt to make aggressive shifts by increasing pressure and adjust timing, then they start to granny the truck real slow around town and complain that it's shifting hard. 

 

The upshift hesitation you're describing is pretty common with the 6sp+5.3 with AFM. It will improve with mileage (about 1500 miles with my 2014). Your best bet is a custom tune but you could wait to see if it starts shifting better on its own. You could also try driving it in "M5 mode", where you shift to M instead of D and use the gear selector toggle switch to choose 5th gear. Leave it like that and it'll stay in V8 all the time. In M6, it'll allow AFM in 6th gear. Try that and see if it hesitates. 

 

A dealer won't be able to do anything for you unless it's something clearly wrong. What you described is normal for the 6-speed, especially with 3.42's. 

[Sin City Trail Boss]

2 hours ago, HondaHawkGT said:

 

It's called a "bump downshift" and it's a common issue on all modern half-ton trucks. They're keeping the torque converter clutch locked up as you slow to a stop, using your forward movement to turn the engine so that the engine doesn't have to burn fuel to keep it spinning while you're essentially coasting to a stop. It's not always a smooth. It affects GM transmissions, the Ford 10-speed, and event the Ram's ZF 8-speed. 

 

You can teach the transmission to downshift better by getting the truck up to 30 mph and just let it coast to a stop without pressing the brake. Every time it downshifts, it's trying to do it as smooth as possible and the computer "learns" or makes adapts so it performs the shifts better. That's where consistent driving is important. Some guys will drive the truck really hard and the transmission will adapt to make aggressive shifts by increasing pressure and adjust timing, then they start to granny the truck real slow around town and complain that it's shifting hard. 

 

The upshift hesitation you're describing is pretty common with the 6sp+5.3 with AFM. It will improve with mileage (about 1500 miles with my 2014). Your best bet is a custom tune but you could wait to see if it starts shifting better on its own. You could also try driving it in "M5 mode", where you shift to M instead of D and use the gear selector toggle switch to choose 5th gear. Leave it like that and it'll stay in V8 all the time. In M6, it'll allow AFM in 6th gear. Try that and see if it hesitates. 

 

A dealer won't be able to do anything for you unless it's something clearly wrong. What you described is normal for the 6-speed, especially with 3.42's. 

Thank you! Great explanation 

[Grumpy Bear]

Best explanation I've ever seen in print. Thank you HondaHawkGT! 

 

I can't reinforce consistency enough. It never stops learning. I have nearly 100K on my 6L80E and drive like a robot but every once in awhile some traffic situation arises that takes me out of machine mode and she will give a different but not unpleasant response than usual. Seems the longer I drive her the more forgiving of these things she gets. 

 

He speaks of the coast down to teach it to downshift. Tis my habit from the beginning to glide into a stop sign and it is very smoot at the stop. Wasn't when I got her and it did take several thousand miles to correct it. Previous guy only had it 1K miles. Now it has the very familiar feel of the Honda Grade Logic downshift of my Civics. Just a mild tug and only down hill and a bit of an uptick of the tachometer. Perfect execution. TC clutch releases on time and in sync. Just be patient and consistent. 

[Sin City Trail Boss]

My plan is to add the Range AFM disabler, but it was suggested by many to wait for the learning process to end before installing it.

 

Just curious how long I should wait before installing it.

[Mandalorian]

3 hours ago, Sin City Trail Boss said:

My plan is to add the Range AFM disabler, but it was suggested by many to wait for the learning process to end before installing it.

 

Just curious how long I should wait before installing it.

When in doubt, keep it until the warranty runs out. 

[Wheelguy]

On 7/16/2019 at 5:36 PM, HondaHawkGT said:

You can teach the transmission to downshift better by getting the truck up to 30 mph and just let it coast to a stop without pressing the brake. Every time it downshifts, it's trying to do it as smooth as possible and the computer "learns" or makes adapts so it performs the shifts better. That's where consistent driving is important. Some guys will drive the truck really hard and the transmission will adapt to make aggressive shifts by increasing pressure and adjust timing, then they start to granny the truck real slow around town and complain that it's shifting hard. 

Say I’ve got a bit over 1000mi on the truck. Would the above do much good at this point?  Not that I’ve driven it hard but there have been some times where I wanted to see what the 6.2 could do compared to the 5.3 I had. I love this 10 speed compared to the 8 speed I had in the 2016.

[TBHiker]

Hey. Not sure if this would help you or not. I've owned two previous 5.3's and a 6.2 in my lifetime. My trail boss custom has 1,300 miles now.

After 100 miles I started to get the jerky shift points at low speed and sometimes around town. Previous GM's owned never did it this bad. 

 

At 300 miles I got fed up with it and came to a stop and floored it up to 70 and let it run through the gears hard. Maybe it's a coincidence but my truck has shifted smooth as butter ever since. 

 

 

[L86 All Terrain]

If you want to fix it you will have to buy a 2013 1500 with a 4L60e. They are shifted via electric over hydraulic solenoids now since the 6L80e and the software/technology is not yet where it needs to be. My 2010 6L80e was slightly smoother than my 2015 8L90e (on my third 8L90e, well 2nd, but they did a T/C at one point too). The new stuff is nice when it works as intended, but that isn't frequent or reliable at this point. Give them 5 years on these TEHCM tranmissions and they will iron it out, but by then EPA will slap them with some new regulations and we will be back to the drawing board with unreliable technology. I wouldn't plan to keep any modern vehicles passed warranty, simply because of how unreliable and untested they are based on EPA demands. 

[HondaHawkGT]

On 7/17/2019 at 6:49 PM, Wheelguy said:

Say I’ve got a bit over 1000mi on the truck. Would the above do much good at this point?  Not that I’ve driven it hard but there have been some times where I wanted to see what the 6.2 could do compared to the 5.3 I had. I love this 10 speed compared to the 8 speed I had in the 2016.

It can't hurt but I also can't guarantee that it'll benefit you. Having a consistent driving style is more important. 

[Wheelguy]

1 hour ago, HondaHawkGT said:

It can't hurt but I also can't guarantee that it'll benefit you. Having a consistent driving style is more important. 

Makes sense. Just trying to understand a bit more of its learning process. Thanks for replying.