Thinkin outside the box: Gearing soloutions...

[saburai]

Hi All!

I run a '99 XJ Ax15/231/D30/8.25

4.10 & 4.56 Nothing in between.

Got to thinkin'...
Are there other than stock fifth gear ratios available?

What about the high range on the 231? Can it be change to anything other than 1:1? Overdrive? Underdrive?

Inquiring minds want to know :sombrero:

[MTNTECH]

4.10 gearing for your 31X10.5 tires would be perfect. I'm running 33X12.50 with 4.56 and now 4.88 is available for the 8.25. If I did it over again it would be 3" lift, 31X105 tires and 4.10 gearing with ARB front and rear. That way the cutout flair's would not be needed. As far as I know high range for the 231 is limited to stock gears, 4.10, 4.56, and 4.88 with 8.25 in back. If you change to a D44 in the rear I think there is a much wider range of choices. Sorry if I wasn't that much help.

[saburai]

4.10 gearing for your 31X10.5 tires would be perfect. I'm running 33X12.50 with 4.56 and now 4.88 is available for the 8.25. If I did it over again it would be 3" lift, 31X105 tires and 4.10 gearing with ARB front and rear. That way the cutout flair's would not be needed. As far as I know high range for the 231 is limited to stock gears, 4.10, 4.56, and 4.88 with 8.25 in back. If you change to a D44 in the rear I think there is a much wider range of choices. Sorry if I wasn't that much help.

Hi and thanks.

Perhaps I didn't state it clearly - what I was wondering was is there different gear sets available for fifth gear for the AX15 transmission or is it possible to modify the 231 transfer case so that the high range is other than a 1:1 ratio.

I have yet to re gear and I'm vacillating between 4.10 and 4.56 with a 32" tire, ARB lockers front and rear.

I saw your reply on the other guys intro thread, beautiful rig!

I will soon be driving up to Autohome Canada and buying either a small Airland or the Extreme. I'm curious as to why you went with the Airland over the Extreme. What size do you have?

I'm intrested in why you would go to a 31x10.5 4.10 combo. I've read that the 33/4.56 set up is optimal, please elaborate.

What MPG do you get with you XJ as it sits in the photos?

I am running a 4.5" measured lift as installed by the PO. It consists of a 3.5 lift kit with 1" spacers in front and 1" shackles out back. I do a lot of high way travel and was thinking I might be better served by pulling the blocks and shackles and staying with the 31's

I just installed a set of AJ's super rails and he is building me bumpers, winch and tire carrier front and rear respectively.

The truck is running T-case drop blocks but I just got a line on a 231 with a SYE already installed. So if I pull the T-case drop blocks, shackles and spacers my net ground clearance will not change and the 31's will fill out the bushwackers a bit better.

Sorry for the long post with so many questions but when I saw the pictures of you rig, well it's pretty much the goal for my truck:victory:

BTW I'm a member over at NAXJA as well. Same name: saburai

Here is what I'm working with:

http://i221.photobucket.com/albums/dd79/badhawk697/Jeep%20XJ/IMG_8110.jpg

[Root Moose]

IIRC there are no different fifth gear ratios for the AX15. The only differences in the top gears are AW4 vs AX15 and I think there is a different OD ratio on the AW4 between the RENIX and ChryCo era transmissions.

[saburai]

Thanks Chris.

What about the 231?

[Root Moose]

The NV231 is only available in 1:1 high, 2.72:1 low. You can do an aftermarket 4:1 low range gear set of course.

The only transfer cases that I am aware of that have a reduced high range are Suzuki SJ and Land Rover.

The LT230 transfer case in trucks like the Discovery have some different gear sets for changing high range. It is a passenger side offset transfer case so then you'd need to change both front and rear axles to run it. Suzuki stuff is too small for a Jeep of course. I'm not certain about Land Cruiser but they are passenger offset both front and rear as well.

It was fairly common to do the 5th gear swaps on the Suzukis but for the amount of effort versus the difference in the few hundred RPM I couldn't be bothered. It was on my to do list but I sold the truck long before I got to that part of the list. :)

I suppose you could throw in a Klune or a Ranger style underdrive/overdirve. But it's a lot of money for little gain in my opinion.

[2drx4]

People over-complicate gearing. Throw a set of 4.10s in and forget about it. Or 4.56. The 11ish% difference really DOES NOT change things very much. Hell, for 31s/32s I'd run a 3.73 gearset if I happened to either have them on hand or found them used. I used to run 31s with 3.55s, and honestly didn't find my XJ at all sluggish, and cruising/highway RPMs were all fine. A 4.0L has lots of bottom end, so it's not like it's the end of the world if you're only taching 2200rpm at cruise.

I also ran 35s with 4.10s. And 37s with 4.56s. My only complaint was I would have really preferred a 4:1 in the tcase, as it was pretty hard on my clutch for crawling. Ordinary driving was fine, FWIW the 35s/4.10s setup was actually lower than stock.

Anyways, there's no options to change your overdrive ratio, unless you change transmissions. An AX-15 OD ratio is .78, and an AW4 is .71. That isn't a huge difference, to say the least. Oh, all AW4s are the same gear ratios. Other things changed on them, but not that. And a NP231 in high-range is just a straight through - so it can only be 1:1

The only other thing I could think of is an aftermarket over-drive. It's just a 2spd unit (1:1 and .75ish:1), ment to bolt between a transmission and tcase. I forget who makes the majority of them - you'll see them in older chevy and ford trucks from time to time, as they had no OD from the factory. They're expensive, and you'd need adapters to mate one to a jeep tranny.

And I guess if you want more LOW gearing options, a Klune V or NWF blackbox could really help you out. However, I wouldn't run one in front of a NP231, that's just tempting the trouble gods.

[Root Moose]

Agree. If you are going to spend the money re-gearing add 4.56 gears and be done with it. Only do it once.

[saburai]

Agreed.

I'm starting to feel like I'm beatting a dead horse.

hmm, 4.10 or 4.56. 4.56 or 4.10. And onand on and on I go:coffee:

[Waytec]

I came across this issue several years ago when I was living back home on the farm. Long story short we did not have the right gearing to pull the cattle trailer out of the barn yard loaded and once on the highway not enough high end.
What we did was go to a trany shop that built racing tranys. I guy use to build for NASCAR teams. He built us one that had six gears and split the transfer case like the high way trucks do. My uncial then took his automatic their for the same issue and he built one for him no splitter in that one. Unfortunely the gentleman has now passed on but other shops should be able to do something for you.

Another option is a set of final drives. Construction equipment use them in everything.
JP mag did a story on them as an April Fools joke, but now there is a company that is building them. (I don’t know who or where)

[MTNTECH]

Hi and thanks.

Perhaps I didn't state it clearly - what I was wondering was is there different gear sets available for fifth gear for the AX15 transmission or is it possible to modify the 231 transfer case so that the high range is other than a 1:1 ratio.

I have yet to re gear and I'm vacillating between 4.10 and 4.56 with a 32" tire, ARB lockers front and rear.

I saw your reply on the other guys intro thread, beautiful rig!

I will soon be driving up to Autohome Canada and buying either a small Airland or the Extreme. I'm curious as to why you went with the Airland over the Extreme. What size do you have?

I have the small Airland, US models are a little different than what you read in the Autohome catalog. Call Mike at US Autohome site in Reno NV, he will fill you in. I just did not see extra weight/strength in the Extreme

I'm intrested in why you would go to a 31x10.5 4.10 combo. I've read that the 33/4.56 set up is optimal, please elaborate.

Mainly MPG, cutting body for flairs, tire cost, personal use requirements, fitment in garage.

What MPG do you get with you XJ as it sits in the photos?

About 13-14MPG

I am running a 4.5" measured lift as installed by the PO. It consists of a 3.5 lift kit with 1" spacers in front and 1" shackles out back. I do a lot of high way travel and was thinking I might be better served by pulling the blocks and shackles and staying with the 31's

I just installed a set of AJ's super rails and he is building me bumpers, winch and tire carrier front and rear respectively.

The truck is running T-case drop blocks but I just got a line on a 231 with a SYE already installed. So if I pull the T-case drop blocks, shackles and spacers my net ground clearance will not change and the 31's will fill out the bushwackers a bit better.

Sorry for the long post with so many questions but when I saw the pictures of you rig, well it's pretty much the goal for my truck:victory:

BTW I'm a member over at NAXJA as well. Same name: saburai

Here is what I'm working with:

http://i221.photobucket.com/albums/dd79/badhawk697/Jeep%20XJ/IMG_8110.jpg

Great looking XJ. If I remember you are touring the country, have to look me up when you get to UT and thanks for the compliments, yours deserve the same back.

[MTNTECH]

The greatest thing about Expedition Portal and NAXJA is the wealth of info from people that reply to our inquiries. Very good replies here, I learned alot.

[IllianaXJ]

I run 33s and 4.88s, and I think it's the perfect combo. It may be a *little* low for some people, but I still only turn 2300 RPM at 65 MPH. 31s and 4.56 would be a good combo also, and would leave you room to upgrade to 33s without a problem in the gearing.

If I were you, I'd hate to spend the cash to regear to 4.10s, eventually upgrade to 33s and end up hating my gear ratio.

I will admit, with the 4.88s and my 4:1 low range, it does end up being too low on some obstacles; I can hit 3rd gear at 15 MPH in low range.

Edit: forgot you had a stick. 4.10s would work fine for 31s, but you may lose some use of 5th gear if you go to 33s.

[saburai]

IllianaXJ, since you and Chris (Root Moose) and others have pointed out 4.56 is the right choice. Or was it 4.10:sombrero:

MTNTECH, Thanks for the complement! If I had a choice I would not have cut the fenders. But since it is a no rust 105,000 mile, never been hit XJ and I was able to buy the truck as it sits for $4300 - well I'm not complaining. They do look kinda cool, but they beg for bigger meats.
We are not really touring the country. More like wandering :smiley_drive: I do want to get back out west. We've got friends all over:victory:

BTW - we are head to the Czech Republic at the end of the month for a month, wish I could brig the XJ:smiley_drive:

As to the Autohome choice, other than the roof bars and I think, a different window set up they seem very close. The Extreme does weigh IIRC, 20lbs more due to more internal braceing and heavier lay up. I don't know if it's needed...
Autohome Canada has a substantially lower price on the airland $1776 vs $2348 for the Extreme. They don't have a Airland in stock, gotta give them another call and find out.

I love NAXJA the amount of info is staggerring! It does, IMHO have a tendency to, at times, bog down a bit with posts that are some times less than helpful...

[IllianaXJ]

But since it is a no rust 105,000 mile, never been hit XJ and I was able to buy the truck as it sits for $4300 - well I'm not complaining.

Meh, I picked up my 50k mile no rust XJ for less than that and immediately cut the fenders :D

I love NAXJA the amount of info is staggerring! It does, IMHO have a tendency to, at times, bog down a bit with posts that are some times less than helpful...

Very true.

.

[ExpoMike]

BTW, the AX15 gear ratios are as follow (found on NAXJA)

1st. 3.83
2nd. 2.33
3rd. 1.44
4th. 1.0
5th. 0.79

5th gear IS an overdrive. Outside of BMW, most 5 speeds, 5th is an OD ratio. Also, everything I am reading says, the AX15 and 4.0L equipped XJ's have 3.07 ratio axles. Looking at the ratio of the tranny, I would look at 4.10's, otherwise 1st might be useless on the street.

I know with my AW4 on 31's, I pull 19-21 mpg highway, as long as I stay under 70 mph. Even towing our Kamparoo, we get 17-19 mpg, again keeping it about 65 mph. When I get into the hills, I end up using 3rd most of the time, which doesn't really hurt the mileage. From what I have read, because the torque curve is fairly flat until about 3500 rpm's, the mileage doesn't drop off nearly as much, even when towing, then a lot of other vehicles.