Down shifting 2015 bighorn 2500 6.4

[Dynaglider]

I have noticed that when coming to a stop, the transmission doesn’t go into 2nd gear. It goes from 6th to 5th, 5th to 4th, 4th to 3rd, then 3rd to 1st. It skips 2nd gear every time down shifting. I do not have a problem taking off from a stop, it goes through all six gears. This is a 2015 2500 mega 6.4 with 65,000 miles. I did have the transmission fluid changed at the dealership about a month ago and found that they did not fill the transmission to full. I had to add 1 1/2 quarts to bring it to full status. I drove for about a month with low transmission fluid. Do I have a problem or does all six speed transmissions skip 2nd gear when coming to a stop.

 

[2003F350]

I never really paid much attention to my 6.4, but I think it's pretty common for any transmission to skip gears when coming to a stop. IIRC my 6.4 would be in 3rd gear at 25 mph cruising through town, chances are it understands you're coming to a stop and that it doesn't need to hit 2nd gear.

 

[Docwagon1776]

I don't know if there is a difference for the HDs, but the 1500 six speed never goes 1-2-3-4-5-6 unless forced to by manually selecting gears.

On it's own, it selects either 2 *or* 3 depending on conditions, but never both. So either 1-2-4 or 1-3-4.

 

[crash68]

It skips 2nd gear every time down shifting

Are you barley moving when it skips 2nd? Most likely the engine rpm doesn't warrant downshifting through 2nd

 

[Dean2]

Put it into tow haul mode and see what it does. I know with mine, if I use second gear to hold speed using engine compression on a hill it will regularly let the revs run up then pull it back down, whether in regular or tow haul. If I set the cruise to 30 KMH it will hold the pickup down to that 30 KMH speed and not let the revs run up. I do not have adaptive cruise, so it uses engine rpm to regulate speed, not the brakes like adaptive does. I have never paid close attention to the down shift pattern when coming to a stop. Will have to watch next time I am driving it.

 

[mtofell]

Are you using the downshift feature by holding down the gear selector when you start to slow? My truck has had a "quirk" since new that sounds a bit like what you're describing. If I'm going 45 or so and coming up to a stop I'll hold the gear selector down for a couple seconds and it picks the target gear as "1".

As it moves through gears is stalls and clunks REALLY harshly around second. I can't tell if it skips it altogether or not. It's harsh enough that it actually chirps the rear tires sometimes. It's done it since new and through two rebuilds of the tranny.

I tried to get the dealer to fix it but they just make excuses and say they can't replicate the problem... which is BS because it does it every time. Anyway, it's really not a huge deal and I just live with it and avoid using the auto downshift feature. I have a lifetime warranty so if it eventually causes more problems I'm covered.

 

[rzr6-4]

the auto downshift feature

You mean the entire premise of every automatic transmission ever?

Joking aside, is that supposed to be some sort of engine braking feature? If you are unloaded it could feel harsh as it is intended for when you are loaded??

 

[mtofell]

You mean the entire premise of every automatic transmission ever?

Joking aside, is that supposed to be some sort of engine braking feature? If you are unloaded it could feel harsh as it is intended for when you are loaded??

It's described in the manual..... you hold the down arrow you use to manually shift for a few seconds and it selects a target gear and pretty aggressively shifts to slow you down. I mainly use it on off-ramps when it will select "2" and avoid the behavior I described in my last post. As long as you're going above about 45 it will go to 2... below that it will pick 1 so I avoid it.

 

[crash68]

you hold the down arrow you use to manually shift for a few seconds and it selects a target gear and pretty aggressively shifts to slow you down.

Those buttons are for the ERS Electronic Range Selection, they don't manually shift the transmission as they won't force an upshift or hold a higher gear below it's range.
Luckily for you the transmission is smart enough to not rapidly downshift faster than the transmission can without hopefully sustaining damage or over reving the engine rpms.
The reason for your trans downshifting so aggressively is because of you selecting so much lower of a gear. Not sure why someone would feel the need to force aggressive downshifts when going 45 unless cornering hard and punching the throttle to pull out the other side.

 

[mtofell]

Those buttons are for the ERS Electronic Range Selection, they don't manually shift the transmission as they won't force an upshift or hold a higher gear below it's range.
Luckily for you the transmission is smart enough to not rapidly downshift faster than the transmission can without hopefully sustaining damage or over reving the engine rpms.
The reason for your trans downshifting so aggressively is because of you selecting so much lower of a gear. Not sure why someone would feel the need to force aggressive downshifts when going 45 unless cornering hard and punching the throttle to pull out the other side.

I'm confused... did you see the snippet from the manual that I am talking about? It specifically mentions a feature that occurs when holding the arrow down for a couple seconds. It's not just the usual clicking through gears. It starts the tranny on an aggressive downshifting to a targeted gear.

 

[BlueMule]

I have noticed that when coming to a stop, the transmission doesn’t go into 2nd gear. It goes from 6th to 5th, 5th to 4th, 4th to 3rd, then 3rd to 1st. It skips 2nd gear every time down shifting. I do not have a problem taking off from a stop, it goes through all six gears. This is a 2015 2500 mega 6.4 with 65,000 miles. I did have the transmission fluid changed at the dealership about a month ago and found that they did not fill the transmission to full. I had to add 1 1/2 quarts to bring it to full status. I drove for about a month with low transmission fluid. Do I have a problem or does all six speed transmissions skip 2nd gear when coming to a stop.

My 2017 2500 Laramie 6.4 with the 66RFE does the same pattern for downshifting; 6th to 5th to 4th to 3rd, skips 2nd and goes right to 1st. Been doing it for 141k miles.

 

[GTyankee]

i can not see why you are manually down shifting unless you are pulling a load.
In that case, you should be using Tow Haul.
With a Load, You should also be taking your foot off the GO pedal, about a half a block before a Stop sign or a Orange or Red Traffic Light.

Assist your automatic transmission when you are carrying or pulling a load.
Like if you are pulling 3,000 pounds, take off in 2nd gear on level ground, First gear if you are taking off at the bottom of a fairly steep grade.
Once you get it rolling, then let it do the work, as long as it does not lug the engine.

Help your transmission, that is the way semi trucks with automatic transmissions are driven

 

[Zoe Saldana]

i can not see why you are manually down shifting unless you are pulling a load.
In that case, you should be using Tow Haul.
With a Load, You should also be taking your foot off the GO pedal, about a half a block before a Stop sign or a Orange or Red Traffic Light.

Assist your automatic transmission when you are carrying or pulling a load.
Like if you are pulling 3,000 pounds, take off in 2nd gear on level ground, First gear if you are taking off at the bottom of a fairly steep grade.
Once you get it rolling, then let it do the work, as long as it does not lug the engine.

Help your transmission, that is the way semi trucks with automatic transmissions are driven

True. Unfortunately, people don't know how to drive/tow these days.

I'd add pumping your brakes (on/off peddle) also helps to stop efficiently when towing.

 

[Dean2]

i can not see why you are manually down shifting unless you are pulling a load.
In that case, you should be using Tow Haul.
With a Load, You should also be taking your foot off the GO pedal, about a half a block before a Stop sign or a Orange or Red Traffic Light.

Assist your automatic transmission when you are carrying or pulling a load.
Like if you are pulling 3,000 pounds, take off in 2nd gear on level ground, First gear if you are taking off at the bottom of a fairly steep grade.
Once you get it rolling, then let it do the work, as long as it does not lug the engine.

Help your transmission, that is the way semi trucks with automatic transmissions are driven

I agree with using Tow/Haul and using the gear limiter to assist with engine braking. There is however no way I know of to have the transmission takeoff in 2nd gear. Leaving the gear limiter in 2, it still starts in 1 and then up shifts. The 4WD system on my wife's Jeep GC has a snow mode, which does make it leave in 2nd, but my 2500 doesn't have that function.

Outside of controlling torque and wheel spin on icy roads, pulling a load I would never start out in 2nd, even if I could, there is no upside. The reason some semis do that is their first gear is REALLY low, used to call them Granny gear in the old manual shift trucks.

 

[2003F350]

I agree with using Tow/Haul and using the gear limiter to assist with engine braking. There is however no way I know of to have the transmission takeoff in 2nd gear. Leaving the gear limiter in 2, it still starts in 1 and then up shifts. The 4WD system on my wife's Jeep GC has a snow mode, which does make it leave in 2nd, but my 2500 doesn't have that function.

Outside of controlling torque and wheel spin on icy roads, pulling a load I would never start out in 2nd, even if I could, there is no upside. The reason some semis do that is their first gear is REALLY low, used to call them Granny gear in the old manual shift trucks.

Yep, good old 'Granny gear.' My dad had 2 different GMC crew cab duallys years ago, one with a 4 speed manual, one with a 5 speed manual, where 1st gear was actually labeled 'L' and 2nd gear was labeled '1'. The 5 speed actually had an OD gear too, so it was L,1,2,3,OD.

We've pretty much lost that ability with automatics today. They could add the programming to 'tow/haul' I think, to not use 1st gear, but they'd probably get far too many complaints about it.

 

[rzr6-4]

The reason some semis do that is their first gear is REALLY low,

Overloaded grain trailer (95k lb at least), easily a 6-7 degree incline, just rained so field was soft. Even in granny I still had to clutch dump to get that old 200hp truck to move. Good times.

 

[Choupique]

Just click the tow/haul button and drive. If the transmission is hunting and the road/load warrant it, it's usually worth locking out the higher gears that it doesn't want to stay in. Modern powertrain control strategies are excellent, and the manual gear lockout helps you help it even further.

Gas engines (especially hemis) love RPMs. Let it scream, you will hurt it far more adding power to it and trying to make it lug. Engine speed is a good thing in every way when towing.

 

[Dean2]

Just click the tow/haul button and drive. If the transmission is hunting and the road/load warrant it, it's usually worth locking out the higher gears that it doesn't want to stay in. Modern powertrain control strategies are excellent, and the manual gear lockout helps you help it even further.

Gas engines (especially hemis) love RPMs. Let it scream, you will hurt it far more adding power to it and trying to make it lug. Engine speed is a good thing in every way when towing.

Agree. My V10 in the 1996 was a much better motor for towing than the 6.4. It made torque at much lower RPM. That said, it did not get any better gas mileage towing and a whole lot less mileage empty than my new 6.4 does. If I towed more, I would have a Cummins. For the few times I need it to tow, the 6.4 works fine, just have to be comfortable with it running 4500 RPM to make good torque.

 

[Choupique]

V10 in the 1996 was a much better motor for towing than the 6.4

I never drove one, but those V10's have really good numbers for engines of that Era.