Intro:

Before I end up with two threads going for the same thing, I figured I'd better start an official build thread.

"The Vehicle" - See the links at the bottom of this post.

1999 Montero Sport Limited 3.5L 4WD A/T

The plan ...

.5 Fix the front end so its drivable! lol! Fix all the misc OEM stuff that needs taken care of
1. Electric engine cooling fans, front bumper/winch, Rhino Lining, skids
2. 2" body lift
3. Rear bumper, lighting, on-board air (ARBs), upholstery (front seats)
4. Transmission swap, NP231 t-case & doubler
5. SAS - ProRock 44s FR/RR w/ ARBs. Leaf rear w/torque arm. 3-link/radius arm front??
6. Exhaust/intake

I haven't decided on axle gearing, t-case, doubler gearing or tire/rim sizes, yet.

Toying with Geolandar M/T 37/12.5/17s, 4.90s, 2.72 in the doubler and a 4:1 Terra Low 231. If I have the number correct (probably not), that should come up to about a 150:1 crawl ratio and just under 9s/in in lo-lo-lo. A tad faster than my M/T - not counting the torque converter.

I was originally planning on 35"s, but with a 2" body lift I can get the same amount of upward travel without body clearance issues, while picking up 1" of ground clearance which would work better for the planed geometry. Have to do the math. I want to keep this lower than my current big Sport. It has 25" from the ground to the chassis, which is too much. Any more would be completely retarded and with a 2" body lift on top of that.... <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> 20-22" would be MUCH better. W/ a 2" body lift and my existing axle/rim geometry it'd be rock solid stable on side hills.

Lots to do first before I get to these, though.

(original threads ...)
1999 Montero Sport Limited A/T model?

Montero Sport Sanctuary - new addition

Edward

we've been using junkyard rubicon rocktrac t\cases they already come with a 4:1 and beefed up parts we just have tom woods order us up some 1310 style yokes and seals for it and i think they do a little machining to them i can't remember and boom oh yeah they are also already the 23 spline short input aswell. If you go this route make sure to get the case out of the TJ rubicon as it has the speedo and the JK model doesn't, which isn't a big deal if you do get the JK model you'll just need to get the dakota digital GPS speedo controller which works AWESOME! So far i am very happy with how its worked i used it in lloyds and pa_jero is using one aswell(both using JK rubi cases).

Thanks! Good to know! Frankly, I was figuring the t-case would be the least of my worries. <img src="/forums/images/graemlins/smile.gif" alt="" /> I hadn't even thought of using the RockTrac. I was planning on doing the same ultra-short shaft conversion on a NP231 w/ the Terra Low that I did with my big Sport and dropping the Dakota SGI in for the speedo. But, the RockTrac would almost certainly be cheaper. Choice will mostly be based on overall length of assembly (edge of bell housing to output yoke on the t-case) and whether I can get an electronic VSS.

I've been through Dakota's stuff. Great products! The GPS speedo looked great and I know others that are using it, but the SGI is simpler and 100% fool proof. Just need an electronic VSS.

Does anyone have the length of the entire assembly? Edge of the bell housing -> doubler -> t-case output yoke? Pictures look like the A/T setup is longer than my M/T setup but its really hard to tell from just a picture. If its shorter than what I have now, I may well want the extra length to clear the rear cross member and maintain my existing drive train geometry.

Ok. Let me make sure I understand this. The Montero V4AW3 - that I need to bolt to my '99 3.5L - needs the 23-spline output and tail-housing from a Cherokee with the AW4/NP231.

The t-case needs the short snout 23-spline input. Is there a reason its the short snout 23? Wondering, because i have the long snout in my big Sport now and I was under the impression that the AW4 came in either short or long.

Edward

Mine is 103:1 so yours is another 50% lower! You might go through a few sets of pads trying to pull that up!

cheers

Nice build.
IMO 2.72: on top of 4:1 is way too low.

I would stick with another 2.72.

Thats what Im doing with my build.

I thinking having both the 4:1 and the 2.72 just give a wide array of options and speaking of options now that your auto your gonna want to be able to still pick what gear your in once in low range so check these guys out i have one of their shifter setups in my montero and love it works great.
http://radesignsproducts.com/Rail.html

I dont get it, why wouldnt you just use factory shifter setup?

Thanks, eurosonic!

Ian, eurosonic: Yea, I know the commonly agreed upon max for an A/T is usually a crawl ratio of 130:1. A lot recommend no more than 100:1.

V5MT1 M/T

Transmission:
1: 3.918
2: 2.261
3: 1.395
4: 1.00
5: 0.829

5.38 axle (crawl ratio):
Lo: 57.3
Lo-lo: 84.3
Lo-lo-lo: 229.3

This is what I wheel now in my big Sport. KIM, it weighs in @ almost 6K lbs w/driver just doing DD service. If I pack it for Moab, its pushing into the high side of 6K lbs. The new one will still sit between 20-25" off the ground (ground to bottom of frame) so its still going to be top heavy like my current Sport. And, I live @ 5500 feet and have to deal with a minimum of one (usually two) 12/13K ft highway mountain pass to get anywhere west, and most of my wheeling is at 8K ft+. Big, loose crap, steep and off camber. I also still need to be able to do 70 MPH on the highway and put 3000 miles on it a trip without issues.

So, I need to make some concessions. This build will still lean more towards an Expedition vehicle rather than a true rock crawler. Just a little less Expedition and a little more crawler than my big Sport now.

V4AW3 A/T (please let me know if these ratios are incorrect)

2.804
1.531
1.000
0.754

5.13 axle:
Lo: 39.1
Lo-lo: 57.5
Lo-lo-lo: 156.5

4.88 axle:
Lo: 37.2
Lo-lo: 54.7
Lo-lo-lo: 148.8


So, I did some math and this is what I came up with. My existing build works pretty dang well on the mountain lower speed highways and great back and froth to Moab on the long stretches where I don't have 12% grades - it BARELY will get me over the passes without ending up in 3RD doing 40 MPH for 15 miles.

Existing build (3.5L)/
5.38 Axle, 34.4 diameter tire:
70 MPH, OD: 3049 RPM
70 MPH, 4TH: 3678 RPM

I have 4.90s in my '03 3.5L (with the Montero 5-speed A/T) so I think I can make some educated assumptions on the 5.13s. 4.90s in the new build I'm almost certain won't work here in CO (definitely didn't in my M/T build!). If I load the '03 up with gear and take it over the passes I'm in 3rd and 4th all the way up - probably 1/2 the time in 3rd. I can't see adding 1500 lbs and 37"s having a positive impact.

5.38s I THINK are too deep for an A/T although that puts me at about 2600 RPM in OD and 3500 RPM in 3RD @ 70 MPH. Better for OD but not great. I'd prefer OD to be about 2800 RPM. <img src="/forums/images/graemlins/frown.gif" alt="" /> Anyway, maybe just a tad deep in 3RD for an A/T.

So, 5.13s I guess. These should be a reasonable compromise. If I were lower in altitude (and stayed there) - even 4K ft - I think I'd consider the 4.90s, but my travel range is 10K vertical feet with a speed range of 75 MPH. A 4-speed A/T w/OD limits what you can do in the axles.

New build (3.5L)/
5.13 Axle, 36.6 diameter tire:
70 MPH, OD: 2486 RPM
70 MPH, 3RD: 3297 RPM

So, this is where I think I'm pretty well stuck at with axle gears even taking into account torque multiplication if I want to have a functional (useful) OD and TC lockup.

These are the projected crawl ratios for the new build.

5.13 axle:
Lo: 39.1
Lo-lo: 57.5
Lo-lo-lo: 156.5

4.88 axle:
Lo: 37.2
Lo-lo: 54.7
Lo-lo-lo: 148.8

I don't wheel A/Ts (except my stock '03) so I'm kinda in the dark here but that is way, WAY lower than my M/T build. CoSport had a '98 Sport w/35"s so I'm going by what I remember when we were wheeling together. The stock crawl ratio was 22.4 which was amazingly pathetic. That was like 52"/sec on 35"s - insanely fast. <img src="/forums/images/graemlins/frown.gif" alt="" />

New build (in/sec):
31.83"
21.6"
7.9"

Existing build (in/sec):
20.45"
13.9"
5"

I HOPE that an A/T will compensate for the difference. Lo-Lo-Lo could go up and that would be fine. 8" or even 10" /sec is no big deal. 31"? That's not so good - I'm not sure that converter slippage will change that number a lot.

2-speed rather than a 3-speed setup? No. 2.72 isn't deep enough by itself to handle any meaningful amount of my wheeling. I'd end up spending 99% of my time in Lo-Lo ( 2.72x2) - might as well just put in a single NP231 with 4:1 and call it a day.

Ian, I don't know. You all are running the Mitsu brakes I presume. I just don't have enough A/T experience to make a good judgement on stopping. What I DO know is my current brake setup can stall it in Lo-Lo-Lo, so .... The ProRocks will be the same as what I have now. Exploder rears w/ 1/2 ton fronts. PowerSlot rotors and Hawk 'green' pads. Enough? Don't know.

Anyway, I don't think I have much of a choice. Need deeper axle gears because of where I live and wanna keep the 3-speed t-case setup. If anyone has a better idea(s)/opinion(s), let me know.

Edward

Ian the idea is to use both you but a switch in then when your wheeling and say your in 4l or 4ll but you want to start and stay in 2 or 3 or hell even 4th that shifter will let you do that in which you can't with the stock setup.

With you there. Having a 3-speed is WAY better than a 2-speed and WAY WAY better than our stock setup. <img src="/forums/images/graemlins/smile.gif" alt="" /> <img src="/forums/images/graemlins/smile.gif" alt="" /> Of course, NO t-case is almost better than 1.9! <img src="/forums/images/graemlins/lol.gif" alt="" />



Uh. I think I understand how this is suppsoed to work. You're using their Rock Shifter? Without the TCM, correct?

I read through all their stuff and if I understand what's what ...

So, you can retain the stock TCM. Which I would think would be necessary for emissions testing - not to pass, but to keep the testers from killing themselves and/or someone else. They're not going to know how to 'shift' an auto. Hell, they can barely test a M/T anymore. <img src="/forums/images/graemlins/frown.gif" alt="" />

The Rail II works in conjunction with the FACTORY floor shifter. If you have a Rock Shifter, the Rail or Baja are not necessary. The question is, would it work in conjunction with the Mitsu shifter?

So, the idea would be to retain the stock shifter assembly and install the Rail II to give stock performance on the highway while giving what basically amounts to clutch-less manual transmission behavior on the trail.

Do I have this correct?

Something else just occurred to me. Since the '99 Sport Limited has a different transmission and PCM, it also has a different selector, right? I don't remember the wiring being the same for the ECM/TCM units and the PCM units. So, if I plan to use the AW with, say, the '95/'96 TCM, I'll need the selector that works with the TCM.

So, another question. What would be the best TCM? I expect that would mean the one that has the fewest connections to the ECM - i.e. standalone - so that means '97/98 or older. Would there be a preference? Are there better options?

AND, I know the 3.0/3.5L bell housing bolt patterns changed in '96. The older stuff isn't supposed to bolt to the newer engines. Is this just a bell housing change or do I need to look at a '97/'98 Montero/Montero Sport AW?

Edward