My research into the 10R80 shift strategy

[Shawn_Mc]

The Transmission shift strategy on these things is mind bending.

The "D" clutch is engaged in P, R,1,2,3,4,6,7,8,10. Where the problem lies is in its oncoming clutch responsibilities when engaged in 6th gear as the oncoming clutch.
If the 10R80 transmission had evil twin redheaded stepchildren, the "E" clutch would definitely be one of them. This other proverbial thorn in your side would be the "F" clutch.
This clutch, the "E" clutch in a 10R80 transmission, is engaged in 1,3,5,6,7,8, and 9th. The real issue becomes apparent pretty quick. This clutch is cycled on 3 times and off 2 times by the time you are in 5th gear. The clutch is on in 1st then cycled off in 2nd, cycled back on in 3rd, then back off in 4th...only to be cycled back on in 5th gear.
The "F" clutch is engaged in R,4,5,6,7,8 and 9th. The quickest path to early or premature degradation to this clutch pack is wide open throttle or heavy-load-indexed 3rd to 4th shifts.

I took that information from an extremely reputable transmission rebuild site.

There are 4 different planetary sets and 6 clutches being pushed back and forth constantly. Personally, I believe most of the driving condition issues come from the A and B clutches that are the braking clutches that engaged when off throttle and the thump as you roll to a stop is most likely the lock up converter clutch finally releasing and allowing the converter to slip.

When you look at ALL of this activity, when these clutches engage, smooth shifts are achieved by intermingling the engagements, IE Clutches for gear A, are slowly being released while clutches for gear B are being engaged, them fighting each other until the speed switch has been achieved and one is all the way on, while the other is finally released. This is standard fare for auto transmissions, but with 10 speeds...it's hectic, and hectic is never good in mechanical assemblies.

Transmission engagement schedule

The A clutch is engaged in R through 6th, then runs free. until decel
The B clutch is engaged in R through 2, then 8th,9th and 10th
The C clutch is engaged in 2 through 5, then 7th through 10th
The D clutch is engaged in R, 1 through 4, 6 through 8th and 10th
The E clutch is engaged in 1rst, 3rd, then 5th through 9th
The F clutch is engaged in R, 4th-through 10th.

Each clutch is engaging or disengaging one of the 4 planetary gear set ratios, each planetary set has three available ratios. Combinations of the ratios are what combine to create a "gear"

That, ladies and gerblemen is a lot of slippin, jukin and jiving.

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[Racket]

Presume that is all 'D' shifting - wonder what the sport mode does differently.

 

[NotBudule]

Mine is only smooth in Sport mode , not sure how that affects the clutches , but "D" is the absolute worst offender, Tow mode much better but still a little clunky on downshifts and no clunks at all in sport...

 

[ccasanova22]

It’s unclear how this shift strategy would affect long term drivability, as some other 8 and 9 speed transmissions (such as those from Toyota and Nissan) in their heavy SUVs seem to last just fine, but I do know that the Ranger 10R80 is so inconsistent sometimes I get a tire squeal when manually shifting 4-3-2-1 going down hills, when the speed is maybe 10-15mph. I shouldn’t hear any tires chirping when REDUCING speed thru a downshift, these are some steep hills and I don’t like riding the brake the whole hill…

 

[Shawn_Mc]

I also drive mine in Tow mode. It's a completely different shift pattern.

It actually seems to go 12345678910 in tow mode.

As opposed to drive were it'll go 134-5 or 6 depending on the mood, then 7,8,9,10
when in just normal drive.

I dont know about you guys, but if I just pop it in drive and head out down the neighborhood at 20mph it'll shift all the way up to 9th or 10th and lock the converter. At 25, it's lugging the engine at maybe 1500 rpm and if you need to accelerate, you hit the gas, go have a coffee and a smoke waiting for it to down shift 7-8 gears, to something useful and then finally go. It's far less offensive in tow mode.
And that ASS is aptly named...mine will kill the engine at a 4-5 second stop with the engine still ice cold.
Some of these "features" arent well thought out. Sport mode is fine until your in bumper to bumper traffic, everything speeds up then slows back down and the thing thinks you're trying to drift the truck sideways into a sporty corner and the revves never drop....which happens to be my daily drive home from work.
Apart from being relatively new and getting 21mpg, I liked the 2020 almost base model Silverado the rental place gave me while this was in the shop for 10 days trying to figure out the TPMS issue, far more.

 

[Big Blue]

I am Constantly amazed at what some people are saying their 10R80 is doing. The variety of behaviors is un believable.

Yes the 10R80 is an incredibly complex beast. To get 10 gears out of 4 planetaries and 6 clutches is going to require lots of engaging and releasing. Comes with the territory. I do tend to agree about the bump coming to a stop. I personally don't understand why the clutch has to be locked up at all in gears 1 thru 3. Unless it has to do with engine breaking. But even then why 1 and 2.

As far as what's different between D and S. It is shift rpms, and clutch pressures. The clutch sequence is the same, other than not skipping 2nd and 4th. Same thing with tow mode.

As far as going up to 9th and 10th at 20 mph. I have NEVER seen mine do that. While I do not monitor my gears all the time, when I have mine at 20-30 mph in town is in 6th or 7th at the max. Also in 10th at 20mph I would think you would be trying to run at less than idle speed. If yours is truly doing that then there is something badly wrong. I understand there is a TSB with a new shift program that some people have had flashed that they say has helped them.

My 2019 XLT is a 8/2019 build, and I am very happy with how mine shifts. Most times I don't even know when it shifts. I have had none of the strange things many people complain about. Yes the first start of the day may have a couple rougher shifts, but I attribute that to the fluid needing to get all distributed to the right places after setting overnight. Usually starting the truck when I get in and then getting organized before shifting into gear minimizes this. The 10R80 definitely does not like cold weather and needs to warm up a little.

Maybe I just got a good one. May I should go buy a PowerBall ticket. I hear the jackpot is getting up there again.

 

[Muscleford]

Mine does not shift into 10th unil 50 to 55 MPH with light to no acceleration load.

 

[Msfitoy]

Anyone here reached 95K miles yet?

 

[MarioCart]

do I gather from that info, that the intermixing of the shifts between the clutches might be more detrimental if you're a grampa on the gas pedal?
Drive it harder and less time slushing the clutches together?

Also, if i read some other data correct, we have only 4 clutch disks vs 5 for other models. how does that play out for longevity.

 

[ccasanova22]

My 10R80 has never went into 9th or 10th at 20mph, that is insane, and would be lugging the engine below idle or fighting the converter to even go down the road.

Mine has, however:
- Squealed tires when engaging reverse (harsh, delayed engagement)
- Locked the back tires up when going down a hill at 10-15mph and selecting 4-3-2-1 from the shifter in “D”
- Gotten stuck between gears with zero propulsion (but engine still revving), then slams back into gear when it figures itself out.

All of these were resolved with a tranny reflash and relearn at around 7-8k miles. Truck now has 15k miles and no issues so far besides the lock of rear tires upon downshifting on steep hills, feels like the TCC clutch is delayed on releasing.

I may go back in for a relearn soon, as it took another 7.5k miles before any odd shifting stuff came up.

 

[ccasanova22]

Also, mine consistently shifts into 10th at 52mph, but I have a Tremor. I’ve never seen it shift into 10th at anything under 52.

 

[Big Blue]

Mine has, however:
- Squealed tires when engaging reverse (harsh, delayed engagement)
- Locked the back tires up when going down a hill at 10-15mph and selecting 4-3-2-1 from the shifter in “D”

How are you selecting 4-3-2-1 from the shifter in "D"? You can only select gears with the shifter in "S".

 

[ctechbob]

How are you selecting 4-3-2-1 from the shifter in "D"? You can only select gears with the shifter in "S".

Not going down the box. You can select them just like in sport mode, just not going the other direction.

 

[Big Blue]

Not going down the box. You can select them just like in sport mode, just not going the other direction.

Ok so you are locking out the upper gears. Yes then you can shift to a lower gear and engine brake the rear wheels. Just like downshifting with a manual transmission. Not really a issue with the transmission then. Just have to watch you don't over rev the engine.

 

[ctechbob]

Ok so you are locking out the upper gears. Yes then you can shift to a lower gear and engine brake the rear wheels. Just like downshifting with a manual transmission. Not really a issue with the transmission then. Just have to watch you don't over rev the engine.

It won't let you. It'll just blink the number and shift when it is safe.

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