4 Lo

[becker87]

So today i put my truck in 4 lo to pull a truck out. Is 4 lo suppose to be crazy low? Is 5 mph at about 3500 rpm the norm? It was just inching along. Now if it is normal that is sweet! Could it be cause the tune? Maybe justin made my tow tune with a very low 4lo? So is that normal?

 

By the way i pulled out a tandom dually dump truck out of the ditch(dumping snow in an empty lot) that got stuck as he was leaving the lot driving up the ditch. I pulled it out in 4 hi cause i wasn't sure if my 4lo was acting normal. He wasn't burried or anything but my truck still pulled him out with no trouble at all.

[foghorn23]

I haven't had my 2011 long enough to experiment with 4 Lo yet, but judging by my previous Silverados that sounds about right. My experience has been that Ford trucks are even lower than the GMs. 4 Lo and a little gas and SOMETHING is going to move

[music]

Yup... normal. Works great crawling down steep, slippery slopes too.

[dewfpo]

Sounds right. Don't forget your multiplying your final drive ratio (transmission first gear x transfer case high range x rear axle ratio) by the low range in the transfer case (2.72:1?) so 5 mph at 3,500 rpm sounds right.

 

DEWFPO

[becker87]

Alright sounds good, thanks guys. I was just amazed how low the gearing is, it was awesome! (well now that i know nothing is wrong )

[KMGZ400]

yeah its pretty amazing isnt it... you should go test it out

[becker87]

yeah its pretty amazing isnt it... you should go test it out

 

 

Maybe next time i need to pull a truck out

[SqwkVFR]

Sounds normal, but it's not that low....

 

In my '64 CJ-5

 

First in the T90 is 3.34:1, Low in the Atlas is 5:1, and the axles are 5.38:1.

 

4000 RPM is about 350 feet / min or 4mph Walking speed with 6850 lb/ft of torque per tire.

 

Total 89.84 to 1 Creeper.

 

My '11 Sierra

 

First 4.03:1 Low 2.69:1 Axles 3.42

 

37.08:1

[Daryl LBZ]

4 lo is the greatest. I use it all the time in the snow just crawling around the yard.

[TRCM]

Sounds normal, but it's not that low....

 

In my '64 CJ-5

 

First in the T90 is 3.34:1, Low in the Atlas is 5:1, and the axles are 5.38:1.

 

4000 RPM is about 350 feet / min or 4mph Walking speed with 6850 lb/ft of torque per tire.

 

Total 89.84 to 1 Creeper.

 

My '11 Sierra

 

First 4.03:1 Low 2.69:1 Axles 3.42

 

37.08:1

 

 

C'mon now, it's low enough to get the job done without putting excess torque on the axle shafts.

 

I agree, it's not rock crawling low, but it's fine for normal use.

 

Use to be 2-1 was the lowest ratio you could get in a t-case

[uchi]

i use low range to back my trailer down my driveway through the snow just so that i can dedicate my focus on the brake and not hit my porch or tree as it gets tight in a spot. it works great. also your lo range is a mechanical gear reduction so the tune would have no effect on its gearing

 

gotta love the crawl boxes, ive got friends who have some pretty crazy crawl ratio, 105:1, 145:1, and so on. usually through dual t case setups or aftermarket gearing in their cases. nothing beats watching a truck climb a steep hill in 3rd gear at idle with no driver controlling it. haha

Sounds normal, but it's not that low....

 

In my '64 CJ-5

 

First in the T90 is 3.34:1, Low in the Atlas is 5:1, and the axles are 5.38:1.

 

4000 RPM is about 350 feet / min or 4mph Walking speed with 6850 lb/ft of torque per tire.

 

Total 89.84 to 1 Creeper.

 

My '11 Sierra

 

First 4.03:1 Low 2.69:1 Axles 3.42

 

37.08:1

[Rat4go]

Sounds normal, but it's not that low....

 

In my '64 CJ-5

 

First in the T90 is 3.34:1, Low in the Atlas is 5:1, and the axles are 5.38:1.

 

4000 RPM is about 350 feet / min or 4mph Walking speed with 6850 lb/ft of torque per tire.

 

Total 89.84 to 1 Creeper.

 

My '11 Sierra

 

First 4.03:1 Low 2.69:1 Axles 3.42

 

37.08:1

 

Don't forget that the typical stock Pickup has 30-31" tall tires on it. Odds are your CJ5 is running something 'just a bit' taller. Taller tires effectively reduce RPM for a given vehicle speed and gear/tcase/axle ratios. It's not gunna cut your ~90 in half to get closer to the 37 number you calculated, but it does make a difference. Just a reminder for folks that had a 4-speed (4L60/65/70) and now have 6 gears. The T-case ratios didn't change much, but first gear is 33% more and the axle is ~10% less (3.73 to 3.42). You're still spinning ~20% faster in first gear than you would have with a 4-speed truck.

[KMGZ400]

yeah its pretty amazing isnt it... you should go test it out

 

 

Maybe next time i need to pull a truck out

 

 

 

test it out offroading... i love using it while offroading.

[Mckenzie]

The first i was ever in 4LO i remember telling myself "this dam thing is pulling like a tractor". I save 4LO for very special occasions.

[SqwkVFR]

Sounds normal, but it's not that low....

 

Don't forget that the typical stock Pickup has 30-31" tall tires on it. Odds are your CJ5 is running something 'just a bit' taller.

 

 

 

Indeed most Jeeps do. Have 31's on the 64. Only thing keeping my axles from grenading, and even so. With the 5.3 in it, I'm sure I'd have no problem snapping them it I wedged a tire rock crawling.