Pardon my thickness but what is locking out gears

[myredracer]

in a transmission all about? What is involved to do it? I don't even know if our '09 F250 can do it. We have a V-10 with 4.1 final drive, rated to tow 12,500 lbs and tow a 29' TT weighing about 7K lbs. We just had a run up about a 10% grade to 4,000 ft. I had tow haul on and it was fine and had it at about a steady 50 - 55 mph. Do I ever need to think about locking out a gear? Or have I got this all wrong and it's something you would do for downhill runs to improve engine braking?

[myredracer]

I'm pretty sure I know lots of things about lots of things, but how auto trannies work isn't one of them. Have rebuilt a few manual transmissions in the past and I come from the era of carburetors when life was simpler. I have no interest in learning how an auto tranny works at this point. I just want to get into our truck, turn the ignition on and go.

I have a better idea of what locking out a gear means now thanks to above posts.

I pulled out our owner's manual and there is no mention anywhere about locking out gears. What it says about the transmission in part is:

All gear ranges are available when using Tow/haul. Tow/haul delays upshifts to reduce frequency of transmission shifting. Tow/Haul also provides engine braking in all forward gears when in the D (Overdrive) position.All gear ranges are available when using Tow/haul. Tow/haul delays upshifts to reduce frequency of transmission shifting. Tow/Haul also provides engine braking in all forward gears when in the D (Overdrive) position.

Our year and make doesn't have a feature of being able to lock out gears and I find that Tow/haul works really well for us so I can forget about having to figure out how to lock out gears.

[Tystevens]

mkirsch wrote:

Tystevens wrote:
Funny, I 'thought' I knew what locking out the gears is, but after reading this thread I'm more confused than enlightened.

In a word: Why?

"Locking out" simply means preventing the transmission from shifting into a particular gear. Nothing in this thread contradicts/confuses that.

Well, we have discussions about torque converter lockup and what is and is not an overdrive and automatic transmission programming and tow/haul use. None of which have anything to do with gear selection. So I'd say about half of the posts in this thread contradict or confuse the question! 😉

If the OP did not understand what it means to lock out a gear, they probably don't understand torque converters and overdrives and torque multiplication due to gearing and all of that. As such, this is a confusing thread!

[mkirsch]

Tystevens wrote:
Funny, I 'thought' I knew what locking out the gears is, but after reading this thread I'm more confused than enlightened.

In a word: Why?

"Locking out" simply means preventing the transmission from shifting into a particular gear. Nothing in this thread contradicts/confuses that.

Different manufacturers at different times have used many different methods to achieve this. Some transmissions "3,2,1" positions would lock the transmission into that specific gear, and prevent any shifting at all. Some transmissions "3,2,1" positions would only allow the transmission to shift UP TO that gear. Some transmissions have a specific button to "lock out" or disable over drive.

The methods are varied, but the end result is the same.

[valhalla360]

No I'll throw another complication in.

We are in the hilly scenario and the transmission starts hunting (we'll assume for the moment even with the T/H mode on it's hunting).

One option is to lock it in a lower grear and run at higher RPM. Not great for fuel economy but not horrible. It can be a bit noisy but shouldn't hurt anything otherwise.

Another option is to play the throttle. If the hills are short, the road is straight and traffic is light, let the truck build up a little extra speed going down the hill and that will help carry you up the next hill. While climbing the next hill let the speed gradually bleed off rather than mashing the pedal down to maintain speed. You will have to play with it to see how much throttle you can give it on the uphill without forcing a downshift. The transmission senses the greater torque of trying to climb a hill and if it get's too large, it downshifts.
- Obviously, don't go stupid fast and risk a crash.
- Don't let the speed drop so much that traffic behind you has to take evasive action.
- If the hills are too long it won't work because as you slow down you need more torque to maintain speed and eventualy the transmission will downshift.

[valhalla360]

myredracer wrote:
We can't turn OD on or off, unlike our old 2000 F150.

Our transmission doesn't seem to hunt. I use tow/haul nearly all the time when towing and it seems to select the appropriate gear at the appropriate time just fine. When I was going up the 10% grade at 50-55 mph, it was running nicely at 4,000 - 4,500 rpm and stayed in the same gear.

It also downshifts nicely when in T/H when slowing down going downhill.

I hear people saying they lock out their transmissions all the time and it seemed like a basic and simple thing to do. I thought maybe you just flicked the right switch or pushed the right button like when switching in an out of T/H mode. I don't seem to have any better idea of understanding "locking out" from the above posts and maybe it's something I don't need to know or worry about.

If the transmission isn't hunting, let the tow/haul do it's thing. It does eliminate most of the issues compared to older transmissions by itself.

Just so you understand:

Hunting doesn't typically happen while on a long steady climb. In that case even the older transmissions will downshift until the engine can hold a steady speed and it will stay there, which is what you want.

Hunting happens when you have lots of up and down sections closely spaced. When you start up a hill, the transmission downshifts to get better torque at the wheels but as soon as you crest the hill with less torque needed at the wheels, the transmission shifts to a higher gear.

In hilly terrain (it doesn't have to be high altitude or even paticularly steep), you can have the transmission shifting all the time and that is hard on the transmission.

Again, if the transmission is holding a steady gear and the engine isn't lugging, you generally don't need to worry about it.

[campigloo]

That's the ticket! Just keep it T/H and ride. The why's and how's are really not that important if you are curious, Banks has some good info on their web site.

[msgtord]

myredracer wrote:
We can't turn OD on or off, unlike our old 2000 F150.

Our transmission doesn't seem to hunt. I use tow/haul nearly all the time when towing and it seems to select the appropriate gear at the appropriate time just fine. When I was going up the 10% grade at 50-55 mph, it was running nicely at 4,000 - 4,500 rpm and stayed in the same gear.

It also downshifts nicely when in T/H when slowing down going downhill.

I hear people saying they lock out their transmissions all the time and it seemed like a basic and simple thing to do. I thought maybe you just flicked the right switch or pushed the right button like when switching in an out of T/H mode. I don't seem to have any better idea of understanding "locking out" from the above posts and maybe it's something I don't need to know or worry about.

Newer trucks have a six speed transmission that has the 5th and 6th gear as overdrive. The transmission has a manual mode that allows for the driver to select what gear and rpm shift points. Just like an old manual transmission except no clutch. You upshift and downshift as needed to keep the rpm's at the optimum range. And you can select to "lock out" the overdrive to prevent the transmission "hunting" on you.

[myredracer]

We can't turn OD on or off, unlike our old 2000 F150.

Our transmission doesn't seem to hunt. I use tow/haul nearly all the time when towing and it seems to select the appropriate gear at the appropriate time just fine. When I was going up the 10% grade at 50-55 mph, it was running nicely at 4,000 - 4,500 rpm and stayed in the same gear.

It also downshifts nicely when in T/H when slowing down going downhill.

I hear people saying they lock out their transmissions all the time and it seemed like a basic and simple thing to do. I thought maybe you just flicked the right switch or pushed the right button like when switching in an out of T/H mode. I don't seem to have any better idea of understanding "locking out" from the above posts and maybe it's something I don't need to know or worry about.

[Tystevens]

Funny, I 'thought' I knew what locking out the gears is, but after reading this thread I'm more confused than enlightened.

[BenK]

First, it's an AUTOMATIC and you are asking a manual tranny question if you
are asking HOW2 shift it

Second, as others have asked, ask if you mean the TC (torque converter, a hydraulic
coupling...think clutch on a manual) lock up or using the shift lever to manually
shift through the gears (and lock out the higher gears)

Again, it's an AUTOMATIC and it has it's computer and software to do the shifting
for you

Then the TH button on the newer ones...engineered to increase the level of
computer management of the AUTOMATIC. Endless threads on 'what is the TH for',
'when to use TH', etc...to the point that even that manual button will be
removed to become AUTOMATIC with an increase in complexity of the computer
system (increase in cost too)

The 'lock up' in the TC is to remove the hydraulic coupling (inherently has a
10%-20% slippage...where the torque multiplication comes from and the losses
with that slippage...heat and lower MPG)

The other is with the shift mechanism. Manually shift the automatic into which
ever it will allow you to and that then locks out all of the higher gears...but
some times the computer will override that manually selected gear and shift
into a higher gear to protect the drive train...mainly the engine from over rev'ing

[spud1957]

The '09 5 speed does not allow you to lock out 5th and only go up the 4th. Moving the gearshift to 4th isn't an option either. Your gearshift options go from D to 3.....

Not the perfect set up. If you want, you can get an SCT tuner from 5Star Tuning that can be customized to lock out 5th if you press tow haul.

One of the options I love about my '11; lock 6th, 5th, or select manual and shift it yourself.

S

[AH64ID]

Camp, Forrest, Camp! wrote:
It sounds ..... lockup.

You should consider deleting this post, it's not even close to an accurate description and will do nothing but cause confusion.

I didn't fully quote it so that when you delete it the record is gone.

[coolbreeze01]

I don't call it locking out, I call it downshifting as needed. My understanding is my 68rfe torque converter will lock-up down to 3rd gear.

[naturist]

bid_time wrote:
Overdrive is not the same as Torque Converter Lockup. Overdrive is a gear with a higher than 1:1 ratio. Locking out a gear simply means it's a gear you don't allow your transmission to shift into. It's normally done with the gear selector lever.

I agree with Bruce: Best answer.

I have no idea about the OPs transmission or controls available for it. I know about mine: 5 speed, with gears 4 and 5 being overdrive gears. It has an "Overdrive off" button that restricts the transmission to gears 1 thru 3, that is, it "locks out" the overdrive, making gears 4 and 5 unavailable. This is useful for dragging heavy stuff up steep inclines, when the transmission (programmed to give best mileage) would otherwise try to do the job in too high a gear.

The usual transmission programming does not have the engine locked into a single gear when you select D1, D2, D3, etc. instead of D. If you choose D3 on a 4 speed transmission, what you have done is simply lock the transmission out of 4th gear. It will behave normally at speeds below those at which it would shift to 4th, but will stay in 3rd and never shift into 4th at higher speeds. This is what is meant by "lock out."