1991 Montero (AKA, Here we go again)

[3Deserts]

Boy...feeling like a dying fish, flopping around between Monty generations, Isuzus, Toyotas...just about anything at this point that'll work and is clean.

So, 1991 Montero: the seller sounds more competent than average and has an example with essentially new mechanicals: crate motor with 20k on it, all new ancillary parts; as he put it, everything under the hood is new. Auto tranny serviced and checked and is solid; new Rancho 4000s, new wheels, new Falken AT tires, rip and stain free, clean pain, no dents, straight frame, no rust, native CA vehicle; 230k miles on the chassis...I emphasized it really needs to be clean assuming all the mechanicals are in order and he said it is.

What should I be aware of with the First gens compared to Gen IIs and IIIs, of which I've become much more familiar than the firsts?

I love the way they look; first gen Monties and Troopers are just so sweet. If this thing pans out and you all can help confirm that the vehicle will hold its own with the Gen II and II.5, then I pray I have a winner because I can't do this searching thing much longer.

Also, am I incorrect in sensing that there's a little more aftermarket support for the First gens? I know I can get ARB lockers, and WST, 4Crawler, Rocky Road, and others stock parts.

Can anyone summarize the 4WD system in comparison to the four mode Gen II?

And finally, is there a quick way to divine if the rear diff is open or an LSD?

 

[Martinjmpr]

As a former 1st gen Monty owner I can probably answer some of your questions. I had a 1990 Monty 4 door from 1992 - 1999. In fact, it still holds the record for the longest time I owned a vehicle and greatest number of miles I put on a vehicle (circa 130k in the 7 years I owned it.)

4wd system: This is easy: Conventional 4wd with automatic hubs. That's it. No ADD, no full time 4wd. It does have "shift on the fly" but I can't remember what the max speed is - the limitation here is probably the automatic hubs. Pretty easy to replace the automatic hubs with manuals if you want to go that route.

Aftermarket: Pretty limited AFAIK. Front suspension is torsion bar, hard to get much lift out of it. I think you can run 31's without much modification. Rear suspension on 4 door models or 2 door V6 models should be 2 link with coils. I think you can get a taller spring but I'm not sure from where (Cal Mini maybe?) 2 door 4 cyl models have leaf springs but AFAIK 1989 was the last year for the 2 door 4 cyl.

LSD: If it's a 4 door V6 (and as a 1991 it should be) then it will have the LSD.

Final comments: Just remember that a lot of the advances in 4wd vehicles were made after this time so don't expect a lot of "refinement." My Monty was perfectly adequate for what I used it for but I only took it on a couple of honest-to-god 4wd roads and it was limited by (among other things) tire size (I was running stock size 235/75/15's which are tiny and really inadequate.)

Campsite in the Black Rock Desert, 1998

Hole-in-the-Rock (HITR) trail, April 1999. Hood painted black because I was tired of the sun constantly reflecting in my eyes!

HITR

HITR

 

[off-roader]

Martin, I remember seeing pics of your rig from the early Mitsubishi Four Wheel Drive Club of N. America Moab trips with Lloyd and Justice... at least it looks like your vehicle.

3deserts,

I'm on my 3rd gen I (first 2 were 4 door v6 models and my current is a 2 door v6 model).

TRACTION AIDS:
LSD: LS models (most came with headlight washers and an upgraded interior) usually had a limited slip. Also check for a sticker either in the driver side door jamb or somewhere on the driver's area (maybe down by the right foot?) indicating it's an LSD. Additionally there may be a sticker on the diff housing. The OE LSD is a very good unit. I did the Rubicon with one and had zero traction issues except for 1 incline where the only that would have helped would have been gears.

LOCKER: ARB makes a front and rear locker for the differentials in a 3.0L v6 model engine and a rear locker for the 2.6L i4 engine model. I'm not sure if the 2.6 and 3.0 front diffs are the same so I cant confirm if the same ARB diff will fit models with either engine.

GEARING:
Stock R&P are 4.6x:1 ratio. You can buy 5.29:1 gears as well as 2.9:1 xcase gearset (Marks 4WD in australia). IIRC, the Aisin transmission & transfer case combo is very similar to those found i some jeeps so there are some options possible here for a dual xcase setup if you really want to go all out but I haven't fully researched this area so I can't verify for sure. Check on 4x4wire.com's mitsu forum for details.

Aisin makes an OE manual locking hub for Mighty Max/D50's that fit the gen I & II front axles. There are also other sources (again see 4x4wire for those).

TIRES:
You can run up to a BFG 32x11.5x15" MT tire (I did) on a 15x8" rim with a neutral offset. The only mod I had to do was a mild torque to the torsion bars. I also let the tires 'self-trim' the rubber bumper end caps. They rubbed off ~1/8" from those end caps.

With a body lift:
For a 33" tire, I did a 2" body lift (just a 1" lift is required) (4crawler.com) and you'll need to torque the torsion bars.

I also elected to use 2" longer coils in back from Valley Spring Works albeit due to longevity issues with their coil springs and their craptastic customer service I would never, ever, ever buy anything from them again.

Lloyd Schwartz runs 35's w/ a 3" body lift, & suspension lift (2" rear and 1.5" front) 5.29:1 ring and pinions, and a 2.9:1 xcase gear (normally 2:1).

ARMOR:
Trail Gear makes rock skids (rocker panel protection) for the toyota Tacoma that just so happens to fit our rocker panel length. You may need to trim the bars that hold it to the frame.

ARB & TJM made bumpers for Montero's however it will be difficult to find them this late in the game, so you'll either want to use a bumper from another rig and modify the mounting to work with the mitsu or make your own. I don't believe in brush guards and cannot even remotely recommend them for anything other than a cosmetic add on which can actually increase your damage in a minor fender bender.

Unfortunately, nobody makes skid plates for the mitsu however a decent fabricator should be able to make a set pretty easily.

SUSPENSION:
Gen II coil springs fit, are progressive rate and will provide 1-2" of lift. Highly recommended.

Toyota Sequoia springs are the same diameter so any spacers made for them will also fit the Montero's coils. I have a pair from Daystar that plan to install soon... ok eventually when I get to it. LOL.

I prefer the monotube design shocks like KYB, Edelbroc, etc. to those Ranchos. Many have said the 4000's are nothing more than fancy monroe's and they won't hold up very well off road.

I'm sure there's more but that's what I can recall for now.

HTH.

 

[4D55 Performance]

I recently purchased my first gen I Montero and they are pretty easy to modify. The rear LSD and drivers bouncy seat is available on the LS models only. A 31" tire will fit with out any mods and 33" tires will fit with a simple torsion bar crank. Realistically the gen I and the gen II are very similar vehicles offroad because they share similar suspensions and drivetrains. Even though the gen I is powered by the weaker 3.0 engine when compare to the gen II's 3.5, the torque to weight ratio is about the same because the gen II weighs more. As for the suspension, you can bolt a gen II suspension to a gen I Montero. Everything from the A-arms, axles, track arms all swap between the two models, if you swap the entire assemblies. The gen II wheel track is about two inches wider. The first gens use a different transfercase than the gen II, but the transfercases are interchagable. So if you want the AWD you could swap in a gen II tcase. You could also swap in an NP231,241 or 242 as long as it is a short input and it's an automatic transmission. Lastly, I highly recommend you get an automatic. The Aisin 4 speed tranny is a real gem. I typically hate automatics, but these autos are great.


Heres a pic of my 1991 Montero LS with 31" tires and a Mombossa roof top tent

 

[3Deserts]

Thanks guys.

I checked it out, drove it, liked it, but passed.

As with all the other older ones I've looked at, it's just too worn and aged for something that's going to be my DD right now.

However, it would make a tremendous dedicated wheeler I think. Tough, raw, simple, very capable. I actually liked it a lot. If I had more time, parking space, and the will to have a project vehicle, I'd buy it in a heartbeat.

 

[ubiqcrew]

I just bought my 157th. vehicle, started at 15 and will be 65 in 10 days..... what a trip! In 1997 I bought a 1991 montero, 4x4, four door, no sunroof, auto, all options, incl. a LSD Bought HD torson bars and turned them up, put air /ift bags in the rear coil springs ( the most important thing to do !) Better on/off road tires, found a winch bumper for it ( what a rare find ) on one of many road trips. Tinted the windows, than made a folding bed in the back, the size of a flat sleeping bag. When I folded the seat, I could push parts of the bed over the seat and lock it together. Made shelves on the other side of the back behind the seat and over the wheel well. Could also store things under the bed frame. I drove it all over the USA and parts of B.C. Canada. NEVER had anything break, ever ! Syn oil in every moving part of the thing ( amsoil ). Serp belt idler pulley started to go out, replaced it and that was it. I sold it to a friend a few years and wish I never had. I found another 1991 everything the same, just white, not sliver like the first one. I sole it to the actor Mike Ferral's nice, she came up to Boise, Idaho and bought it, was driving back to L.A. area and had it on C.C., never had a 4x4 and on a winter road south of Twin Falls, Idaho, rolled it end over end. Crushed it into a semi flat mess and she got a black eye. Montero's are one tough 4x4 and if you ever find a good one grab it or send me a note.

 

[ultrakill]

The rear LSD and drivers bouncy seat is available on the LS models only.

I don't think this is true, I have an auto-trans 1990 LWB Montero RS. It has a bouncy seat and LSD. The car was completely stock when I got it about a year ago.

 

[rxinhed]

After 1989 US model year, you could apparently check option boxes, rather than just limit to trim levels. I've seen a roll up window RS with a sunroof.

 

[ultrakill]

After 1989 US model year, you could apparently check option boxes, rather than just limit to trim levels. I've seen a roll up window RS with a sunroof.

Haha that's funny. I wish vehicle manufacturers still allowed options instead of packages.

So I have a question, on the LSD sticker by the door it says: "do not move wheels while only one wheel is on ground" or something to that effect. Does that mean when the truck is in P? What would happen if I'm wheeling and one tire is off the ground in back? Isn't that the whole point of LSD to send more torque to the tire with grip?

I know it's not a true "locker" but doesn't the LSD act sort-of like a locker so you can indeed get power to the tire that has grip?

 

[plh]

That means when you are stationary and have 1 rear wheel up on a jack.

 

[rxinhed]

I can't recall if I'd driven through some runoff from the water truck, but here is a burnout my Raider produced with the LSD:

Nothing modified, stock Raider 2.6L 5-speed with 31" Hercules all-terrains.