4 Low use it or lose it.

[thatJeepguy]

LOLWUT!

explain that 4a driveline bind to us all.

No problem,
In full lock steering maneuvers in parking lots at low speed the front/rear axle speed differential is enough to activate the clutch packs. In normal t cases it causes wheel hop, in this tcase the clutch packs deal with that energy and it causes a lot more ware in the system.4A is a convenience feature. Ive already seen 2 4A tcases burn out on Broncos on utube.

 

[smurfslayer]

hmm... got to look into this more but ‘2 4a transfer cases busted on youtube’ does not a problem make. Raptor has been using the same transfer case since ’17. We’re 5 years on now and they’re not dropping like flies.

 

[Nex]

Raptor has been using the same transfer case since ’17.

What's a transfer case? Is that when the Starbucks employee transfers you a case of coffee in the drive-thru?

 

[thatJeepguy]

hmm... got to look into this more but ‘2 4a transfer cases busted on youtube’ does not a problem make. Raptor has been using the same transfer case since ’17. We’re 5 years on now and they’re not dropping like flies.

The transfer case is not the issue. Where an issue can arise is the usage. i’m arguing that driving all the time in 4A on dry pavement is not a good idea regardless of what anyone tells you.

 

[FordTechOne]

No problem,
In full lock steering maneuvers in parking lots at low speed the front/rear axle speed differential is enough to activate the clutch packs. In normal t cases it causes wheel hop, in this tcase the clutch packs deal with that energy and it causes a lot more ware in the system.4A is a convenience feature. Ive already seen 2 4A tcases burn out on Broncos on utube.

The T-case uses a wet clutch for 4A; it’s electronically controlled by the TCCM. It doesn’t just automatically start applying due to a slight differential in wheel speed. The TCCM modulates the clutch based on inputs such as steering angle, vehicle speed, throttle position, wheel speed, and engine torque. It won’t engage the clutch just because the wheels are turned. In fact, it actually decreases duty cycle as steering angle increases.

The TCCM monitors clutch slip and driving conditions. If driving conditions are severe enough to require 4H, it will automatically engage and display a message stating “4x4 TEMPORARILY LOCKED”.

I don’t understand why someone would not want 4A capability, it’s perfect for inclement weather allows the full capability of the truck to be used on dry surfaces.

 

[thatJeepguy]

The T-case uses a wet clutch for 4A; it’s electronically controlled by the TCCM. It doesn’t just automatically start applying due to a slight differential in wheel speed. The TCCM modulates the clutch based on inputs such as steering angle, vehicle speed, throttle position, wheel speed, and engine torque. It won’t engage the clutch just because the wheels are turned. In fact, it actually decreases duty cycle as steering angle increases.

The TCCM monitors clutch slip and driving conditions. If driving conditions are severe enough to require 4H, it will automatically engage and display a message stating “4x4 TEMPORARILY LOCKED”.

I don’t understand why someone would not want 4A capability, it’s perfect for inclement weather allows the full capability of the truck to be used on dry surfaces.

Again, I'm referring to driving 100% of the time on dry pavement with 4a on. If given the option, im taking a traditional tcase every time.

 

[Halo Raptor]

Funny, growing up with 4WD's I was always told to put it in 4WD every one in awhile and drive straight and slow for a minute or so to make sure its lubed and works before needing it and finding out it doesnt work. Never knew if it was a wives tale or not

 

[lobsterman]

Funny, growing up with 4WD's I was always told to put it in 4WD every one in awhile and drive straight and slow for a minute or so to make sure its lubed and works before needing it and finding out it doesnt work. Never knew if it was a wives tale or not

Same

 

[1BAD454SSv2]

If your going to try 4 low do it in front of your house drive back in forth in straight line with out turning steering make sure it engages and a you can get back out into 2wd drive. If it gets stuck you will be in neutral and not going anywhere . If it all works then go out and drive it in the dirt for a bit . My neighbor in his 2018 f150 learned this he got Transfer Case stuck in neutral between 4 hi and lo , actuator was bad out in the middle of BFE , had to get towed .

4A is for the rain
4H is for racing Boost launch . No turning of the steering wheel. Good for fast driving in the Dirt
4 Low soft sand and pulling people out , light touch on the go pedal. Don't get crazy you will break something

 

[doodman4321]

Very appreciative of this thread. I had used my 4H and 4L earlier this year in my Jen Juan, so I figured I was good until the Minnesota winter, which could come as early as Halloween (insert "remember the '91 Halloween blizzard?" story). After reading, I figured I'd check just to be safe. Sure enough, I turned the knob to 4H and got the big orange "Check 4x4" error with the wrench. 4L was the same. Nothing was engaging, just staying in 2wd. I thought it might have been the transfer case shift motor based on a different thread here, but it turns out I need a new transmission wiring harness. All covered by the extended warranty, thankfully. Still, this thread is a great reminder to check 4H/4L every so often.