Not Motivating Well in 4lo: is this normal? (1 Viewer)

[SaturnAscends]

During the recent snow storm I tested out the CDL as I hadn't really had occasion to use it before. It would seem to lock in fine: I heard a click and the diff lock light came on immediately. However, when I put i tin D, 2, or L, I would just get an initial short burst of torque, then the truck would slow down considerably, and the motor would just rev up to 3k with very little forward movement. It almost felt like the Tcase was still in Neutral, except that I was moving forward, albeit sluggishly. I just didn't get the bite I'd expect in low range.

One time I noticed it lurch forward after the engine had revved up to 3k or so, but after I stopped it happened again.

I had no issues in AWD/4hi; in fact I seemed to have much better traction without the center diff locked.

Is this just how it works with a slushbox 4wd? Or is there something else going on?

 

[Comet]

Check fluid in transmission. I can not remember what year you have. Keep truckin’ brother.

My ‘97 has a 2nd start button. If I forget to press it, 1st gear start is very lively, followed by an anemic second gear run.

 

[rockstate45]

4low multiplies the torque through the transfer case gears. So, in 1st gear, you’re going to be going a few mph before shifting into second, and then a handful more before going into third. It should lock you out of 4th while in low range.

 

[SaturnAscends]

Check fluid in transmission. Keep truckin’ brother.

I thought of that but was confused since there's no issued in 4H. I will check the level later though, IIRC you have to run it through all the gears first

 

[SaturnAscends]

4low multiplies the torque through the transfer case gears. So, in 1st gear, you’re going to be going a few mph before shifting into second, and then a handful more before going into third. It should lock you out of 4th while in low range.

Yea but I still noticed the hesitation when I locked the trans into 2 or L

 

[Comet]

Hi range behaves differently than low in my rig. High is sluggish, non responsive , and down right apathetic to skinny pedal input. Low range is a gangster with an attitude.

 

[SaturnAscends]

Hi range behaves differently than low in my rig. High is sluggish, non responsive , and down right apathetic to skinny pedal input. Low range is a gangster with an attitude.

Yeah that's what I thought before but I just noticed this sluggishness the other day.

One other thing I should mention is that I did get up to 25 mph or so with the center diff locked and in D when the roads were very slick and snowy. I used to do this in my old truck in 4lo/4th gear, but is this a no-no with the auto/full time 4wd set up on the LC? I'm really missing the set up on my old Tacoma where you could just put it in gear and go, without all the hesitation of the auto..

 

[Comet]

I gave flogged both my 80 and my ‘03 Tundra in low. 80 was more controlled, like a 70 year old walking on the sidewalk vs the Tundra. Granted, two different animals.

 

[mudgudgeon]

One other thing I should mention is that I did get up to 25 mph or so with the center diff locked and in D when the roads were very slick and snowy.

Shouldn't matter if the surface was slick.
Dry asphalt is a problem because thr lack if wheelspin causes the driveline to bind up and can break things.

IME, if you get the driveline bound up, and nothing breaks, no harm, no foul.
You either break something or you don't.

 

[SaturnAscends]

Shouldn't matter if the surface was slick.
Dry asphalt is a problem because thr lack if wheelspin causes the driveline to bind up and can break things.

IME, if you get the driveline bound up, and nothing breaks, no harm, no foul.
You either break something or you don't.

So you don't reckon the hesitation in 4lo is an issue then?

 

[mudgudgeon]

So you don't reckon the hesitation in 4lo is an issue then?

In not sure about the hesitation.

I'm saying having had the CDL locked at 25mph is not a cause

 

[Broski]

You should not have hesitations or slippage in low range.
When you say you were checking out the CDL do you have a button or you're shifting into low range

 

[SaturnAscends]

You should not have hesitations or slippage in low range.
When you say you were checking out the CDL do you have a button or you're shifting into low range

No just shifting to low range. Haven’t added a switch.

 

[Broski]

Mine a 94 so a little different.
But something seem off, you should not be getting hesitations.

 

[Broski]

After thinking about it, I thinking your just spinning your tires and the truck not moving much.
4 low is not good for mud, ice or snow, just makes your tires spin. and you said it works fine in high
Find a dry hard packed surface and try 4 low my guess is that it's fine

 

[SaturnAscends]

After thinking about it, I thinking your just spinning your tires and the truck not moving much.
4 low is not good for mud, ice or snow, just makes your tires spin. and you said it works fine in high
Find a dry hard packed surface and try 4 low my guess is that it's fine

I thought of that but I tried it going straight on dry pavement and it seemed to do the same thing

 

[Broski]

I thought of that but I tried it going straight on dry pavement and it seemed to do the same thing

Not sure then, transfer case is gear driven and either works or it doesn’t if the transmission works in hi it should work in low as well

 

[SaturnAscends]

Not sure then, transfer case is gear driven and either works or it doesn’t if the transmission works in hi it should work in low as well

Ok, occasionally I get some grinding when I shift to L but nothing too bad. I don’t suppose there’s any reason the transmission would act up in L but not H..

 

[80t0ylc]

Not sure then, transfer case is gear driven and either works or it doesn’t if the transmission works in hi it should work in low as well

The T/C uses some other gears for reduction in lo range. So, IMHO it might be a T/C issue. Be nice to see and hear what @Ozark80 is talking about - what I'm saying is people use different terms for describing the same thing sometimes. Be nice to watch a video and listen and watch what OP is describing.

 

[80t0ylc]

Also remember, the tranny uses different shift points in lo range, if all ECU's are working correctly. Might even be an electronic issue.