Low range with 3.92s

[Hubbs]

I just got a new Ram 4x4 with 3.92s. I tried out the 4WD system the other day and found that 4x4 Low is unusable. It's so extreme that it redlines at about 5-6 mph. WTH? I guess the math makes sense, but I guess I'd hope it would be at least usable with factory gearing options.

It also acts funny when putting it into 4WD Low. It lurches forward and it's actually difficult to keep the truck from creeping forward at idle. If I try to drive away, it sounds and feels like the trans is slipping. It bucks around a bit and finally accelerates to about 6 mph.

Do I have a problem with my trans or transfer case? I didn't expect it to buck and then rev without any acceleration. Doesn't feel right.

 

[jlb]

Sounds pretty normal to me. Low range gives you a huge torque advantage, so any power transmitted through the torque converter while you are sitting there in drive gets multiplied, and without a clutch to disengage it you feel a pretty good lurch putting it in drive.

5-6 mph is only the top end of first gear, where are your other 6-8 gears (do you have the 6 spd, or the 8?)?

 

[1500ram12]

4 low is meant for crawling, no more than a couple miles an hour. Or if you are stuck and need more engine power with less wheel spin. Only other real use is if you need to pull something that is stuck and you need to break it loose enough or move it far enough to get into 4 hi

Sent from my SM-N900V using Tapatalk

 

[Andy578]

i never had an issue with 4low lurching, did you have the truck warmed up or did you just jump in and go? it'll lurch in any setting if she's not warm

as others have said 4low is supposed is for very low speeds and lots of torque like pulling someone that's stuck. my only complaint about 4low is that with the 8 speeds gearing the second you touch the gas she wants to shift but that slight delay slows you enough that it then wants back into 1st so i usually end up with the truck constantly going between 1st and 2nd

 

[MyOhFive]

my only complaint about 4low is that with the 8 speeds gearing the second you touch the gas she wants to shift but that slight delay slows you enough that it then wants back into 1st so i usually end up with the truck constantly going between 1st and 2nd

lock it in 1st with the buttons?

 

[14hemiexpress]

4 lo is ment to be used for crawling, hill climbing, pulling people out, pulling trees and bushes out that kind of stuff. In 4 low it gives you a 2.64 ratio over standered 2wd or 4hi. With the 8 speed 3.92 and 2.64 t case it gives you a final ratio of 48.74, vs the standered 18.46. Just to finish the math at 1000 rpm in first with 2wd or 4hi you will be going 5.3 mph with the 4lo range you would be moving 2 mph that shows the mechanical advantage you have.

 

[clh1220]

4 low acts like that in every truck I've owned. You should almost never have to use it. It is great for pulling out landscape you don't want anymore.

 

[Hubbs]

Thanks for the inputs.

I didn't lock it in 1st - good idea to try. It really feels/sounds like the trans is slipping as it'll rev up without the truck moving.

It was warmed up completely. I tried accelerating about 1/4 throttle from a stop and let it shift through the gears. It was weird in 1st gear and then acted pretty normal, considering the extreme gearing.

Think I'll play with it some more (what she said) and see if I can figure out what it's doing.

 

[14hemiexpress]

1st is pretty extreme in the 8speed

 

[Andy578]

lock it in 1st with the buttons?

1st is simply too low. if i could lock it into 2nd it'd be perfect since it's still low enough to provide plenty of power but sadly not an option

Thanks for the inputs.

I didn't lock it in 1st - good idea to try. It really feels/sounds like the trans is slipping as it'll rev up without the truck moving.

It was warmed up completely. I tried accelerating about 1/4 throttle from a stop and let it shift through the gears. It was weird in 1st gear and then acted pretty normal, considering the extreme gearing.

Think I'll play with it some more (what she said) and see if I can figure out what it's doing.

it'll rev up quite a bit in 4low since all that power is going into torque. like you said 2nd feels much better but under load the truck doesn't want to stay there so you'll bounce between gears a lot. this is mainly a problem due to the 8 speed being geared low combined with the 3.92 axles. my silverado is a 5 speed and the axles are something like 3.42 and it feels much better in 4low. i've been using 4high most times that i'd usually want 4low simply because it feels like it's being a lot harder on the transmission then it needs to be

 

[regularcab2500]

I didnt read anywhere that you put it in neutral first...i dont mean to offend you if thats a given but some dont put it in neutral anymore since the shift-on-the-fly transfercase...4low wont properly engage if you dont start from neutral..
Again sorry if this is a given just had to throw it out there!

If so andy brings up a good point..possibly the massive 1st gear in the 8speed requires a severe amount of load to counteract the excess power causing it to lurch and not feel right altogether..realistically you shouldnt use 4low unless youre rock crawling or creeping through snow covered mud..or pulling someone out which i experienced but 4low did the trick and walked the car right out of the ditch

 

[14hemiexpress]

I didnt read anywhere that you put it in neutral first...i dont mean to offend you if thats a given but some dont put it in neutral anymore since the shift-on-the-fly transfercase...4low wont properly engage if you dont start from neutral..
Again sorry if this is a given just had to throw it out there!

If so andy brings up a good point..possibly the massive 1st gear in the 8speed requires a severe amount of load to counteract the excess power causing it to lurch and not feel right altogether..realistically you shouldnt use 4low unless youre rock crawling or creeping through snow covered mud..or pulling someone out which i experienced but 4low did the trick and walked the car right out of the ditch

Mine pops up on the evic and put in neutral to finish shift, when I try to put it in 4lo so you cant miss that step. Second gear in the 8 speed is lower than the 1st gear in the 6 speed. I've used 4 low to pull a few trees and bushed and its a beast with 6speed 3.55 couldnt imagine 8 speed 3.92 that puppy would be rearing to go!

 

[Andy578]

I didnt read anywhere that you put it in neutral first...i dont mean to offend you if thats a given but some dont put it in neutral anymore since the shift-on-the-fly transfercase...4low wont properly engage if you dont start from neutral..
Again sorry if this is a given just had to throw it out there!

If so andy brings up a good point..possibly the massive 1st gear in the 8speed requires a severe amount of load to counteract the excess power causing it to lurch and not feel right altogether..realistically you shouldnt use 4low unless youre rock crawling or creeping through snow covered mud..or pulling someone out which i experienced but 4low did the trick and walked the car right out of the ditch

truck literally won't go into 4low unless you're in neutral and under a certain speed(5mph i think)

yes if you get a big enough load such as pulling a tree stump there's zero issues. if your pulling say a stuck car that doesn't need much force there's issues with the truck jumping between 1st and 2nd. the problem i had was that 4high would cause my tires to spin a lot putting me at risk of getting stuck myself but with 4low the spin was pretty minimal but hell on the transmission. it's one of those damned if you do, damned if you don't scenarios

 

[clh1220]

truck literally won't go into 4low unless you're in neutral and under a certain speed(5mph i think)

yes if you get a big enough load such as pulling a tree stump there's zero issues. if your pulling say a stuck car that doesn't need much force there's issues with the truck jumping between 1st and 2nd. the problem i had was that 4high would cause my tires to spin a lot putting me at risk of getting stuck myself but with 4low the spin was pretty minimal but hell on the transmission. it's one of those damned if you do, damned if you don't scenarios

I don't know where you get it's hard on the transmission. That's the way it is designed to work. Your not hurting it , by just using it.

 

[Andy578]

I don't know where you get it's hard on the transmission. That's the way it is designed to work. Your not hurting it , by just using it.

constant shifting is putting more stress which will cause more wear then should be necessary. they also start heating up when they are shifting like that

 

[14hemiexpress]

constant shifting is putting more stress which will cause more wear then should be necessary. they also start heating up when they are shifting like that

Sort of, shifting doesn't put any stress on the transmission when a transmission shifts it slips, that's what gives you the smooth shift. The slipping causes heat witch will burn stuff up. If your worried about turn the Trans temp gauge on and watch it and don't let it get hot and you'll be fine.

 

[RLJ10X]

I love four low. It's such a friggin monster.

 

[blackbetty14]

quick question, you have to be on neutral to engage 4low… but when you get going and your in 4low can you switch to 4high on the knob without going to neutral again?

Say I'm in the snow and use 4low to get out and Im crawling at 2-3mph can I just turn the knob to 4high? do i need to release the gas some and turn the knob? or do I have to pop it into neutral and then go to 4hi?

 

[loveracing1988]

quick question, you have to be on neutral to engage 4low… but when you get going and your in 4low can you switch to 4high on the knob without going to neutral again?

Say I'm in the snow and use 4low to get out and Im crawling at 2-3mph can I just turn the knob to 4high? do i need to release the gas some and turn the knob? or do I have to pop it into neutral and then go to 4hi?

Any shift involving 4 low requires neutral to complete.

 

[jlb]

quick question, you have to be on neutral to engage 4low… but when you get going and your in 4low can you switch to 4high on the knob without going to neutral again?

Say I'm in the snow and use 4low to get out and Im crawling at 2-3mph can I just turn the knob to 4high? do i need to release the gas some and turn the knob? or do I have to pop it into neutral and then go to 4hi?

I usually try to be at a complete stop when shifting into 4 low because sometimes when you are moving, even slowly it can clunk into place pretty hard.

Also, 4-low is actually NOT hard on your trans assuming you don't let it shift all over the place. 4-low is actually better on your trans because your trans is under virtually NO load. The shifting of the trans in 4-low would be considered low energy shifting because there is very little torque input during the shift. You are more likely to generate lots of heat from your converter than from the clutches shifting in this scenario.