Going downhill offroad JK

[deathbyfire]

I drove a jeep a few years back at Jeep 101. One of the things they demoed was going up and over a large hill. On the way down the jeep was controlled and crawled down slowly on its own. I tried this in my 2007 JK X the other day and that wasn't the case. I ended up having to brake all the way down.

I don't know a ton about cars so not too much ridicule if this is a stupid question, but what do you all think would be the difference and what made that other jeep crawl down so controlled. It was a stock jeep. Is there something I can mod on mine to make it crawl down like that?

:dontknow2:

[jquader]

were you in 4lo?

[deathbyfire]

Yeah, I was. I shifted into 4 wheel low, but then a few days later found out that I had broken this disc that threads the cable on the shifter. I wonder if it didn't go into 4wl and was maybe stuck in 4wh

[I Drill]

i'm sure you were in 4hi. being in 4lo will result in very little if any breaking.

[jquader]

yeah, sounds like you never made it to 4lo.

Try again once you're repaired. :yup:

[deathbyfire]

Yeah, I went to show my buddy who drives an FJ how it goes downhill and it just went like a mad truck downhill. I told him that isn't how it happened on my old jeep and the last one I drove.

[deathbyfire]

Kewl, will do. Had it repaired already. I will take it back out and give it a go. Thanks for the fast replies.

[flyer415]

I would also think that you want to be in the lowest gear possible. Mine is a standard so i leave it in 1st as well and let the engine compression do the braking. If your's is an auto then I would think that you would want to shift into L1 as well. (Not quite sure what the readings are on the auto)

[deathbyfire]

Yeah, it is an auto. When taking it offroad you are saying I should shift out of regular drive?

[flyer415]

Yeah, it is an auto. When taking it offroad you are saying I should shift out of regular drive?

When going downhill I would put an Auto out of regular drive and put it in a low gear...Yes.

Most people drive their autos in D continuously. The other gears are available and should be used. In this situation I would definitely use L1 or whatever it is labeled for going downhill.

Are there other times that I would use D3 or L2...yes. Whenever I towed something like a boat at the max weight I would start in a lower gear and shift up while I was driving/cruising.

I have standard trucks and jeeps so I have never offroaded with an auto so no response from me on if you should do it as a default measure.

My initial response is really regarding going downhill. Engine compression works great.

[yetibear]

It's funny, I remember doing that Jeep 101 maybe 4/5 years ago, and one of the big things they wanted us to see was how it held back going down hill. And it really did keep a constant speed going down a fairly steep incline. Now, a good few years later I have no idea weather that Jeep was in 4lo or hi, but I know exactly what you are talking about.

Usually, for the terrain I play in, when I am in 4wd I drop down to second and stay there(in 4hi), there is no place to really go fast, and if I need to I will use 4lo, and 2nd holds me back on the few places I want a little compression breaking.
Where I go is up a steep, switch backey fire road, so when I come out I descend in 4lo, in second. There is so much compression brakeing that I have to give it gas to keep up speed. I prefer that feeling of driving down over just going for the ride down.

that is with a auto in a Rubi.

[mikeyfl]

where are you wheeling at? :brows:

[deathbyfire]

Here is a link to google maps where we went. It was a blast. You can tell it is a well used offroading fun spot. It is the place just to the east of 75. Raulerson road and 301. Go to the end of the road.

Link (http://maps.google.com/maps?f=q&hl=en&geocode=&q=raulerson+ranch+road+tampa&sll=28.047857,-82.349889&sspn=0.007594,0.012231&ie=UTF8&ll=28.04869,-82.35137&spn=0.015188,0.024462&t=h&z=15)

[mikeyfl]

hmm. another guy was talking about a spot in the same area but off jefferson rd.

all you florida people need to start hanging out in the sunshine state forum (http://www.jk-forum.com/forumdisplay.php?f=53).

edit that: that other guy was you. hahaha. :duh:

[yetibear]

where are you wheeling at? :brows:

to bad he replied so fast, I was gonna be a wise a$$ and just say,

HERE

http://i199.photobucket.com/albums/aa169/yetibear/cccoffroading.jpg

[doojer]

Like the previous poster said, if you are going down a steep grade offroad and you have an auto, get into 4 low and put your auto tranny all the way down into 1st. That will give you the best compression braking. But, if you don't have a Rubicon and your gear ratio is a little higher like mine, you may still have to use the brakes a bit, but not much. You should see your rpms rise as the compression braking does its thing.

[mikeyfl]

to bad he replied so fast, I was gonna be a wise a$$ and just say,

HERE

http://i199.photobucket.com/albums/aa169/yetibear/cccoffroading.jpg

you need to speed up you circle drawing skills. :bleh:

[yetibear]

you need to speed up you circle drawing skills. :bleh:

I looked at his link:eek2:, I'm embarrassed.:yup: If he can find a place to wheel, and have fun, in all that mess,:dontknow2: I got to go wheel a lot more!:thumbsup::thumbsup:
:rollingeyes:

and I do draw slow sort of circles.

[deathbyfire]

Speaking of gear ratios. I have an JK Unlimited X. What is the gear on mine and the rubi and what is the difference. I am thinking about switching mine out but don't know a lot about them. I have 35" tires now and a 4" lift. I would like to go to 37" tires, but don't know if I need more life and what gear. Also, I can't add too much height because I will not fit in my garage. Will going from 35 to 37 just add 2 inches? The gear ratio and the limited slip diff thingamajig stuff I have never really had explained. I can program a computer all day long and take apart a laptop with 200 screws and put it back together with no instructions, but have never gotten into my vehicles enough to understand them.

[mikeyfl]

2007 gears would be 3.21 or 4.10(opt. tow package) and 4.10 for rubis.

2008 would have 3.21 or 3.73(opt. tow) and 4.10 for rubis.

some people can live without the upgraded gears, some can not. ive been living with my 3.73s and 35s. they arent really on my must have list...

good info. (http://www.jk-forum.com/showpost.php?p=211276&postcount=4)

[deathbyfire]

I bought mine used. I don't suppose there is anyway for me to tell what gears are in mine.

[yetibear]

Speaking of gear ratios. I have an JK Unlimited X. What is the gear on mine and the rubi and what is the difference. I am thinking about switching mine out but don't know a lot about them. I have 35" tires now and a 4" lift. I would like to go to 37" tires, but don't know if I need more life and what gear. Also, I can't add too much height because I will not fit in my garage. Will going from 35 to 37 just add 2 inches? The gear ratio and the limited slip diff thingamajig stuff I have never really had explained. I can program a computer all day long and take apart a laptop with 200 screws and put it back together with no instructions, but have never gotten into my vehicles enough to understand them.

for your tires think of a 37 inch hole, and you center a 35 inch donut in it, the difference is spread all the way around, it isn't a 2 in gain in any one spot. for fitting in a garage, with a 2 inch increase in tire size I would add 1 in to the Jeep as it stands now. That is if both the 35's and 37's are true to those sizes, and the sidewalls are not significantly stiffer on the 37's. If everything is equal adding 1 inch should give you it's actual hight difference with a little safety for good measure.

[yetibear]

for your tires think of a 37 inch hole, and you center a 35 inch donut in it, the difference is spread all the way around, it isn't a 2 in gain in any one spot. for fitting in a garage, with a 2 inch increase in tire size I would add 1 in to the Jeep as it stands now. That is if both the 35's and 37's are true to those sizes, and the sidewalls are not significantly stiffer on the 37's. If everything is equal adding 1 inch should give you it's actual hight difference with a little safety for good measure.
actually that is totally wrong, I was illustrating it for my self and I got my mental picture all back asswards.You will end up only gaining 2 inches, but only the bottom half really counts and that is still 1 inch gained

[mikeyfl]

I bought mine used. I don't suppose there is anyway for me to tell what gears are in mine.

did it come with a tow hitch and wiring? if you do and it is stock, then 4.10s.

from another thread:

As far as your gear ratio, lift up the rear put it on jacks spin the drive shaft until the tire makes 1 complete rotation. If your shaft spins 4 times you have the 4.10, if it spins less than 4 than youre looking at the 3.21

[yetibear]

mikeyfl got me thinking about drawing circles, and I wanted a donut, so you got donuts in circles.

From the center of the hub, to the outside of the tread, a 35 is 17.5inches, a 37 is 18.5inches. Tread to tread, through the center is 35 & 37, so you gain an inch on the top, and an inch on the bottom. Only that bottom inch can give you height gain, so you only get one extra inch from a 2 inch larger tire.

[muddpuppy01]

yes yeti either way you put it you only gain a inch if things are true size


i.e. I cannot recall what spefic tires or used but there are a set of 37s bigger than a set of 38s

[yetibear]

yes yeti either way you put it you only gain a inch if things are true size


i.e. I cannot recall what spefic tires or used but there are a set of 37s bigger than a set of 38s

Thanks, glad you understood what I meant.
I just wanted to make it right, cause you know some one will come along and not to kindly let me know I don't know the difference between diameter and circumference. So the donut in a hole showed what I meant, it just wasn't what I wanted to illustrate.

And just you wait, some one will still point out that I am really talking about radius!:rotflmao2::rotflmao2:

[muddpuppy01]

only the diameters matter in this situtation

[yetibear]

only the diameters matter in this situtation
:thumbsup:


it's only the radius from the center to the ground that gives you height.:rotflmao2::rotflmao2::rotflmao2:

[pearl-drum-man]

I bought mine used. I don't suppose there is anyway for me to tell what gears are in mine.


All automatic 2007 JKs have the 4.10 gear ratio.

[pearl-drum-man]

Just to add to the original question, as stated being in 4LO and 1st gear should do the job, there have been a couple of situations with my TJ (3.07 gears) on really steep grades I used a couple clicks on the emergency brake to give a smooth/slow descent. In a tippy situation gaining too much speed combined with a hard panic application on the brake pedal could be bad.

[JKJeremy]

All automatic 2007 JKs have the 4.10 gear ratio.

ummmmm, i don't think so but o.k.....i'm not saying you're wrong but you might not be entirely right about that either :thinking:

[deanthemachine04]

yeah as far as i know that is true. all auto's in 07 have 4.10's which is great.

[Ghostship]

What your X doesn't have, that the Jeep101 Rubicon had, is the 4:1 geared Transfer Case. That will make all the difference in the world when it comes to compression braking a JK Unlimited.

Unlike previous Wrangler Auto's, the new JK's are computer controlled, and have special programming when in 4Low. You may not notice any difference in descents with it in D or 1st.

[pearl-drum-man]

That's odd....I could've sworn I had to get the Towing package to get the 4:10 gears on my '07.

In 2007, you could get the 4.10 four ways:

Buy a Rubicon

Buy an Auto

Option the Tow Package

Get the 4.10's for a $50 option independent of all of the other possibilities.

[sspronin]

I have property in up state NY and the trail in is very steep and rocky. I put my JK X auto in 4LO and 1st gear and I go down just fine with no braking. 4LO 1ST gear is the way to go.

[yetibear]

Will this be on the test?

yes.:yup:.

[bigdeenus]

2007 gears would be 3.21 or 4.10(opt. tow package) and 4.10 for rubis.

2008 would have 3.21 or 3.73(opt. tow) and 4.10 for rubis.

some people can live without the upgraded gears, some can not. ive been living with my 3.73s and 35s. they arent really on my must have list...

good info. (http://www.jk-forum.com/showpost.php?p=211276&postcount=4)

The 2007 spec sheet from DC says all '07 autos come with 4.10's as well...

[bigdeenus]

All automatic 2007 JKs have the 4.10 gear ratio.

crap...he beat me to it!:wah:

[-MAW-]

to bad he replied so fast, I was gonna be a wise a$$ and just say,

HERE

http://i199.photobucket.com/albums/aa169/yetibear/cccoffroading.jpg

omg too funny :rotflmao2::rotflmao2::rotflmao2:

gd 1

[Sieran]

This hill wasn't TOO steep.... but it was enough that a few times the wheels felt like they slid a little.

http://www.youtube.com/watch?v=IJ1RrYKW-Vs&feature=related

I was in 4-lo 1st (6-speed) gear all the way down and i didn't have to touch the brakes once. Infact, i felt like i had to use the gas more than the brakes to keep up with the rest.

[medbender]

here in cali, we do alot of wheelin in steep hills with either no rock or dc granite. in this type of cond. i like to be in 4lo l2 so the wheels dont spin so slow that i end up sliding down the hill. i'd rather give a little break and have control. slow is not always the safest option. of course with a good rock base you cant beat crawling down in l1