4Lo Question (1 Viewer)

[Blake Loggins]

Is there some special sequence of events to putting my '08 LC in 4Lo?? Ive been in several situations over the past year where while in 4Lo and offroading on a steep hill or rock climb that the vehicle feels like it is in 4Hi. To me this is very dangerous. One of the situations I was in Colorado on the hill climb at top of Middle fork of the swan and got stuck because my car wouldn't go. The best way to describe this is, if you had a manual trans vehicle and you were trying to start out pulling a trailer in 5th gear. The engine really seems lugged down and the tires will not spin. The 4Lo light is on and the vehicle is noticeably in low range leading up to the hill. But at times when under strain up an incline it just wont go. Any others have this happen?? Am I doing something wrong?? Any thoughts or suggestions is much appreciated. My 80 series doesnt do this and neither does my Jeep wrangler rubicon or any other 4wd Ive ever owned.

Thanks!

 

[luke27617]

I have MY16 so different transmission. Definitely not the same experience. You can feel very low end torque. How is your experience in crawl control mode?

 

[chilibit]

Limp mode induced by heat?

 

[Rigger]

Definitely something wrong. Parking brake set?

My 4LO is very low and very torquey.

 

[linuxgod]

Sequence is stop, put the transmission in Neutral, shift to 4Lo, wait for light to turn on, put trans in Drive. Not complicated.

You'll know if you're in 4Lo once you start moving because you can hear the gears whine (which is normal). If the transfer case doesn't whine, you're not in 4Lo.

You say you have an '08. What's the mileage? When was the last time the transmission, transfer case, and front and rear diff fluids were changed?

I find in 4Lo it's very torquey. If you're up against a rock or ledge you might feel like it's lugging under idle or light throttle until you give it enough gas, but once you get on the gas it'll whip you around. On really steep declines I wish it had a higher crawl ratio, but it'll still limit you to maybe 5mph in 1st gear.

Do you use the manual shift mode when in 4Lo? You do have to come to basically a complete stop to get the transmission to drop back into 1st gear automatically, so if you're rolling slowly and just in Drive perhaps the transmission is actually holding 2nd or 3rd gear. Run putting it in manual mode and downshifting to first. The only other way I could imagine feeling lugged down would be if your brakes are dragging or if you pressed the 2nd gear start button.

 

[GordJ]

I am assuming that your 4low light on the dash isn’t flashing? I know this is obvious but I wanted to check.
Is your traction control on? It can reduce torque to ground if the tires are slipping. On my ‘08 I have to put the tranny in “N” , not “P”, and start the truck to make sure the low range engages and the light stops flashing.

 

[Malleus]

Sequence is stop, put the transmission in Neutral, shift to 4Lo, wait for light to turn on, put trans in Drive. Not complicated.

You'll know if you're in 4Lo once you start moving because you can hear the gears whine (which is normal). If the transfer case doesn't whine, you're not in 4Lo.

You say you have an '08. What's the mileage? When was the last time the transmission, transfer case, and front and rear diff fluids were changed?

I find in 4Lo it's very torquey. If you're up against a rock or ledge you might feel like it's lugging under idle or light throttle until you give it enough gas, but once you get on the gas it'll whip you around. On really steep declines I wish it had a higher crawl ratio, but it'll still limit you to maybe 5mph in 1st gear.

Do you use the manual shift mode when in 4Lo? You do have to come to basically a complete stop to get the transmission to drop back into 1st gear automatically, so if you're rolling slowly and just in Drive perhaps the transmission is actually holding 2nd or 3rd gear. Run putting it in manual mode and downshifting to first. The only other way I could imagine feeling lugged down would be if your brakes are dragging or if you pressed the 2nd gear start button.

^this. Once it engages, it's golden. (I have 112k on mine)
I have intermittent shift motor problems, along with CDL lock actuator problems, which I think are both due to trash in the grease in the mechanical part of the actuator. I haven't been stranded (enough) yet to inspire me to tear it down. Doesn't sound like your problem though.

 

[marketShark]

if you roll you windows down and try to shift to 4lo from 4hi, do you hear the actuator/ transfer case changing? its not very loud, but makes a noticeable and audible change between the ranges

 

[Blake Loggins]

Thanks for the replies guys. To answer a few of the questions:
1. 4lo light is on and not flashing
2. parking brake is obviously not set (but the vehicle acts kinda like it is)
3. You can hear the 4lo engage when you twist the knob on dash, you can hear the actuator switch it.
4. Sometime I do have to turn the engine off and recrank it to get the 4lo light off.

Sounds like something is definitely not right. It does sorta seem like traction control could be the issue. To be clear, the 4lo works fine until put under strain such as the tire up against a large bolder then the engine just bogs. You can literally push the gas pedal to the floor and the engine will not rev. Do you guys even press the traction control button off or on when engaging 4lo? or should that not matter?

 

[TonyP]

Nope. Shift to neutral, twist to 4Lo, shift to drive, climb rocks.

 

[Dan Higgins]

Same sequence that others have said (Stop, neutral, turn the dial to 4Lo, wait for it to fully engage, shift to whatever grear you need). The only thing I add is that I most often also shift to "S mode". Not always. Shouldn't be necessary when climbing. But I just like a bit more control.

Also, when you go into 4Lo, at least on my MY16, it enables a lot of the multi-terrain features like crawl and hill climb and so on. You would still need to press the a button to actually use most of those features. I can't see them causing what you are describing. Just that it is something that is different when in 4Lo.

 

[TeCKis300]

Sounds to me that you are in 4lo with the transfer case, but the transmission has shifted into a higher gear for whatever reason. As others have mentioned, you'll want to put it into sport mode to better control gear selection.

Note the logic in sport is not specifically selecting gears, but telling the tranny the highest gear it can automatically select. S3 will allow the tranny to automatically shift between 1,2,and up to 3. Exception is s1, which indeed selects 1st gear explicitly.

 

[Dan Higgins]

I use S3 a LOT when of road. in fact, on most dirt roads I go to 4Lo and S3 almost immediately. Gives me more control on any descents. I'll go higher (S4 or S5) some times but generally S3 is good enough for me on those roads. I don't mind the engine reving to 3K on occasion.

 

[CLHickman]

Interesting topic and conversation.

I'm only getting into a max of 3rd gear in 4Lo, what all are you getting into as your highest? This gets me up to 30MPH @ ~3.2K RPMs. Is this abnormal?

Thanks,
Chris

 

[Dan Higgins]

I have used 5th (out of 8) a number of times. (Higher than that and I'm probably not off road and just shift back into normal.) Wait, to be honest, I'm not certain it has actually gone to 5th. I have set it as high as S5 and I do believe that it does there but I don't remember double checking to see if the RPM changes when I drop it to S4. At least not that I can remember. But I'm pretty sure it was using 5th gear.

 

[foeix]

Thanks for the replies guys. To answer a few of the questions:
1. 4lo light is on and not flashing
2. parking brake is obviously not set (but the vehicle acts kinda like it is)
3. You can hear the 4lo engage when you twist the knob on dash, you can hear the actuator switch it.
4. Sometime I do have to turn the engine off and recrank it to get the 4lo light off.

Sounds like something is definitely not right. It does sorta seem like traction control could be the issue. To be clear, the 4lo works fine until put under strain such as the tire up against a large bolder then the engine just bogs. You can literally push the gas pedal to the floor and the engine will not rev. Do you guys even press the traction control button off or on when engaging 4lo? or should that not matter?

My 08 seems to default to 4th gear when in 4LO. I manually shift it as necessary. Have you confirmed what gear it is in?

 

[CLHickman]

I guess I should add that whenever you shift to the manual max gear selector it always defaults to a 4th. That does not mean you will reach 4th though. I played with the truck the other day while in 4Lo and I could select up to 6th gear, but the truck would go no higher than 3rd. I could tell by the number of shifts as well as reducing the manual mode until I forced a shift point.

This is with the 6-speed transmission, which I should add for reference. Curious if you guys are actually in the gear you believe you're in. If so, then maybe I've got a faulty transmission =/

 

[mcgaskins]

Interesting topic and conversation.

I'm only getting into a max of 3rd gear in 4Lo, what all are you getting into as your highest? This gets me up to 30MPH @ ~3.2K RPMs. Is this abnormal?

Thanks,
Chris

If you want to go higher than 3rd gear in 4 low, you should take it out of low. What scenarios would you want to be in 4 low at higher than 30mph?

 

[CLHickman]

If you want to go higher than 3rd gear in 4 low, you should take it out of low. What scenarios would you want to be in 4 low at higher than 30mph?

@mcgaskins - you misunderstood, I don't have a need. I'm responding to the posts previous about being in 4th - 5th gear in low. My truck doesn't do that, and if theirs does, am I missing something?

 

[Swampmonger]

Sorry to piggyback on the OP's question, but since the thread has gone a little more general I'd like to get some clarification. I look at 4L like lockers. I only use it if I get in trouble (or think I might). Am I looking at it wrong? It sounds like if I'm on a trail where I have to ride the brakes and be careful on the gas that maybe I should be in 4L?