[Country Jeep]

Well, I just now finished up making the stock specs, hope everything is in order.

Common Design

All MJs were built as a full unibody design with the body and frame rails tied/welded together as one piece and cannot be removed, however, the rear is a fully boxed frame with the bed bolted to it, making the bed removable. All MJs have solid axles front and rear. The suspension consists of coils for the front and leaf springs for the rear. All MJs came with disc brakes in the front and drums in the rear.

Also, all MJ's through all years are equipped with a height sensing proportioning valve that is used to change the bias of the brakes if the bed had a load in it.

For those curious to the differences in Cherokee's and Comanche's:

The taillight lenses are different from a Cherokee's, the wheel flares are the same (as a 2dr Cherokee), the front doors off of 4-door XJ's (84-92 at least) are swappable, hoods are swappable from 84-92 models Cherokee's (Cherokee's above 92 used spring-loaded hinges), and all mechanical/electronic parts forward of the firewall ARE identical.

Body

The body comes only in standard cab model with a rear double-top hatch tailgate. Comes in longbed or shortbeds two-tone versions. Long bed versions come with a larger gas tank than the short bed and is located front of the axle. Short bed version was not avaiable in 1986.

Interior: Door panels are removable as stock. Bench seats and bucket seats DO NOT have the same mounting brackets as XJ seats. Gauge cluster is removed by 4 screws. Gauge cluster during 86' have mechanical-powered gauges. On 87-90 gauges, The speedometer uses a cable, but all gauges 91-92 use a computer cable.

Wheelbase:

short bed 2wd=113.1 4wd=112.9 (18 gal tank)
long bed 2wd=119.6 4wd=119.4 (16 gal [longbed, opt shortbed] 23.5 gal [opt longbed; standard from 1989])

Engines

2.5L I4 TBI (fuel injected) - 117 hp @ 5000 rpm, 135 ftlb @ 3500 rpm - used in 86 and updated in 87-90 to 121hp (2.5L became MPI in 91 and was rated for 130hp @ 5250 and 149 ftlb @ 3250) ---

Fuel Miser package was available, lowering the HP
to 100hp and included a 4 speed manual trans, no tail gate, undercoating, and 3.31 axle gears. the 4x4 Miser got the same treatment as well as no spare tire or brackets.

GM 2.8L V6 - 115 hp @ 4800 rpm, 145 ft lb @ 2400 rpm - used only in 86

Italian VM 2.8L Turbo Diesel - 140 hp, 236 ft lb torque - used in overseas MJs

2.1L 4 cylinder Turbo Diesel - 85 hp, 132 ft lb torque.

4.0L I6 EFI "Power Tech" - 177 hp @ 4750 rpm, 220 ft lb @ 4000 rpm - used 87-90
4.0L I6 MPI "Power Tech HO" (High Output) - 190 hp @ 4750 rpm, 220 ft lb @ 4,000 rpm - used in 91-92

Transmissions

Manual Transmissions
AX4 - 4 speed manual - manufactured by Aisin - used 86-92 with 2.5L I4 and 2.8L V6 engines and 2.8L turbo-diesels
T4 & T5 - 4 & 5 speed manual - manufactured by Borg Warner - used only in 86 with 2.5L I4 and 2.8L V6 engines
BA10/5 - 5 speed manual - manufactured by Peugeot - used only up to 89
AX5 - 5 speed manual - manufactured by Aisin - used with 2.8L V6 and 87+ with 2.5L I4
AX15 - 5 speed manual - manufactured by Aisin - used with 4.0L I6 engines

Automatic Transmissions
Torqueflight 904 - 3 speed automatic - used only in 86 with 2.8L V6 and 2.5L I4 engines and 2.8L turbo-diesels
AW4 - 4 speed automatic, electronically controlled - manufactured by Aisin - used from 87-92 (87-92 models include a Power/Comfort button that adjusts the shift points, also known as a towing package; all transmissions came with the towing package and came with a transmission cooler; 88+ models used Power/Comfort switch for off-roading)

Pete M implied information about this that might override anything written above, where his information is correct. It was too hard for me to take his info and add it in, atleast for now...

Originally Posted by Pete M

The "Metric Tonne" or "Big Ton" or "payload package" was designed for hauling, was only available on longbeds, and consisted of an AMC-20 rear axle in 86, Dana 44 rear axle in 87-92, heavier duty springs front and rear, tougher shocks, the larger tires, fullsize spare and 15x7 wheels. In the AMC-20, the only gear ratio was 4.10, Dana 44s got stuck with the standard ratio available with the specified drivetrain combo (3.08 for 4.0l/manual, 3.54 for 4.0l/autos, and 4.09 for 2.5l/manuals).

Transfer Cases


The transfer cases used are all chain driven with aluminum housings. NP stands for "New Process" which is the brand, if you will.
NP207 - "Command-Trac" part-time only - 2.61:1 ratio low range - used 86
NP231 - "Command-Trac" part-time only - 2.72:1 ratio low range - shift pattern 2H - 4H - N - 4L - used 87-92
NP228 - "Select-Trac" part-time OR full-time - 2.6:1 ratio low range - used 86
NP242 - "Selec-Trac" part-time OR full-time - 2.72:1 ratio low range - shift pattern 2wd - 4part-time - 4full-time - N - 4LO - used 87-92

Driveshafts

Front Driveshaft - On 86-87 MJs (NP207 t-case) the front shaft is a "GKN" style shaft. On 87-92 MJs (NP231/242 t-case) the front is a "double cardan" two-piece driveshaft with a CV joint at the transfer case end.

Rear Driveshaft - The rear is a one-piece shaft with standard u-joints at both ends. The slip yoke is located on the output shaft of the transfer case. On 86-92 models, the yoke slides in and out of the transfer case and is lubricated by the ATF fluid internally.

This information might override what's written on the rear-driveshaft, but has no method of being added in as 'stock'

Originally Posted by Pete M

Actually, there were 2 different styles of rear shaft offered, though I have yet to determine a logical pattern behind which MJ got which. The other one was a 2-piece design, but not the usual 2-piece you're thinking of where one side slips on the other. The MJ 2-piece had a large outer tube on the transmission side and a smaller tube on the axle side. They are fused together with a thick rubber isolator designed to reduce vibrations.

Axles

Front Axles

Dana 30 high pinion - reverse cut - 27 spline, 1.16" diameter shafts, 7.13" ring gear - used 86-92 (all axles are vacuum disconnect, and have 5-260x u-joints)

Rear Axles

AMC-20 - 29 Spline, one piece axle shafts, 8.875" Ring Gear; Metric Tonne axle in 86.
Dana 35 non c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used 86-89
Dana 35 c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used 89-92
Dana 44 non c-clip - 30 spline, 1.31" diameter shafts, 8.5" ring gear, 2.75" axle tube - used 87-89 on some(not all) MJs equipped with towing package.
(note for D44's: All MJ's equipped with the stock D44 come with the Metric Ton Package)

All rear axles are made of a spring under axle design.

Gearing

3.07 - used with 4.0L engine / manual transmission
3.31 - used with 2.5L Fuel Miser option
3.55 - used with 4.0L engine / automatic transmission
4.10 - used with 2.5L engine usually
4.56 - rare but can be found on some older (~ 89 ~) models with 2.5L engine and auto transmission

NOTE:
Cooling Systems

Open style - any normal cooling system used today. Opposite of closed style described below.

Closed style - has no radiator cap and utilizes a pressure bottle. This style cooling system was used in 87-90 MJs.

Airbags

No airbags during Comanche timeline.

Trim Levels

86 - Custom, X, XLS
87 - Base, Pioneer, Chief, Laredo, SporTruck
88 - Base, Pioneer, Chief, Laredo, Eliminator, SporTruck
89 - Base, Pioneer, Chief, Laredo, Eliminator, SporTruck
90 - Base, Pioneer, Chief, Laredo, Eliminator, SporTruck
91 - Base, Laredo, Eliminator, SporTruck
92 - Base, Laredo, Eliminator, SporTruck

Production Numbers

MJ (4x4 only)

SWB/LWB
1986 23,251/xxxxx
1987 6,199/6,685
1988 6,895/9,167
1989 5,354/5,021
1990 3,283/2,129
1991 5,188 (TOTAL)
1992 3,142 (TOTAL)

A little info on dimensions:

Originally Posted by Pete M

Overall length was 179.3" for shortbeds, 194.0" for longbeds
Overall curb height was 63.7" for 2wds, 64.7" for 4wds
Track width was 57" with the 15x6 rims, 58" with the 15x8s
Body width at the rear flares was 71.7"
Length of inside of box at the floor was 73.7" sb and 88.5" lb
Width of box at the floor is 55.3" for both sb and lb
Width between wheel wells is 43.8"
Box depth is 16.4"

This is a edited copy of the XJ stock specs. If anything here is incorrect or if you would like to add the dimensions and production numbers, please post info

The OTHER notes section!!!

Originally Posted by Pete M

Curb weight for the 2wd short bed was 2912
4wd sb was 3076
2wd lb was 2959
4wd lb was 3141

Payload for stock MJs is 1475 lbs (1200 for 86), Metric Tonne was 2205 lbs. The maximum tow rating an MJ was ever given was 5000 lbs (4.0L required). 2.5Ls seem to have been limited to 2000 lbs and 2.8Ls were 4200. I cannot find any rating listed for the stock bumper. Every brochure mentions a class 1,2,3 hitch needs to be installed for towing.

Special thanks to: cj7xjmj, Pete M, krodeMJ, MJDriver, Drahcir495, Guumba, 1986Comanche, and Snowplow.

[cj7xjmj]

You missed the Metric Ton paskage which used the D44 in the rear. You also forgot to mention that the 90-92 had a height snsing proportioning valve that was used to change the bias of the brakes if the bed had a load in it. You also forgot the long and short bed. As for the trim levels youy forgot the eliminator, or the Sport Truck. You also forgot to mention the fact that there was 2 different size gas tanks, and that the rear axle is a spring ubder axle design. Besides fron all those things good post.



Patrick

[krodeMJ]

I don't know a lot about stock specs for the MJ, and mine was purchased from someone who didn't know a lot either. However my MJ seems to conflict with the stock specs you listed. I'm trying to find out more about mine to begin with, but this is what I know so far. It seems to be a base Comanche, however is it possible it has a towing kit? How would I check (theres a tow hitch, but that doesn't tell me much.)

It's an '88, 2.5 liter I4, with a 5 speed manual transmission. (this seems to conflict with your list.)

No other special features as far as I can tell. It's not a long box, and it's the original dark maroon color.

Can anyone tell me anything else about it knowing that information, or where to look on the jeep? I had found an online VIN decoder for the Comanche, but not having much luck finding it again (could swear I bookmarked it...)

[cj7xjmj]

I found my build sheet on my 90 MJ behind the drivers side door panel, and one Under the seat, not that I was looking for them. I was pulling out the bench seat to replace them with buckets, and The door panel was coming off so I could replace the window regulator.



Patrick

[Country Jeep]

Alright, changes made. And krodeMJ, I can't seem to find any info about a towing "kit". I'll keep looking...anybody know about a towing "kit"?

Alright, any problems or information I need to fix or add?

[krodeMJ]

Sorry, I'm not sure if it's called a towing kit/package, but I've seen the reference around some places. It may refer to what I've also seen called the 'metric ton package'. Not sure of what it's supposed to be called, or include, but I know one of the features of that option is different gearing in the rear differential.

[Country Jeep]

Well I wouldn't want to be reposting info on that but.......but the towing package IS the power-comfort switch, but I'm still not sure about the metric-ton package. It might be different, I'll study up on it. But cj7xjmj, what exactly do you mean by metric-ton package? That switch on ur dash?

[cj7xjmj]

The metric ton package was an option for the MJ. It included the D44 rear, and a few other things, I am not sure of all the items cause they are extremely rare. The power comfort switch came on almost all the early model AW4 trannies.


The towing package included a transmision cooler and 3.73 gears.


Patrick

[MJDriver]

The towing package pretty well consisted of the power switch on the dash. When it is switched on it flows more fluid and thus helps it lockup better. I think a read the hitch and trailer light relay were actually optional.

I haven't confirmed it, but I think I have the metric ton package. I've got a longbed with a D44 rear and the power button, but no wiring in the back for a trailer.

PS. On the specs I think the HO engine came out in '91, and the gas tank is always located in front of the rear wheel.

[Country Jeep]

Alright, I've studied up on all of this and listen to ya'll

Towing Package: Known as the Power/Comfort swtich, it changes the timing between shift points, as the spec sheet shows.

I'm still having trouble finding the metric ton package info, but it's still listed in the spec sheets.

As I'm just starting on this spec sheet, anything else need to be fixed or added? I'm still waiting for dimensions and production numbers.

[Drahcir495]

All info from Illustrated Buyer's Guide JEEP by Jim Allen

MJ (4x4 only)

SWB/LWB
1986 23,251/-
1987 6,199/6,685
1988 6,895/9,167
1989 5,354/5,021
1990 3,283/2,129
1991 5,188 (TOTAL)
1992 3,142 (TOTAL)

[Country Jeep]

Originally Posted by Drahcir495

All info from Illustrated Buyer's Guide JEEP by Jim Allen

MJ (4x4 only)

SWB/LWB
1986 23,251/-
1987 6,199/6,685
1988 6,895/9,167
1989 5,354/5,021
1990 3,283/2,129
1991 5,188 (TOTAL)
1992 3,142 (TOTAL)

Thanks a bunch! (and are you sure that wasn't Tim Allen??? )

[cj7xjmj]

All the early AW4 transmisions came with the power comfort switch. This is not the towing package option. That was standard with the aw4.




Patrick

[Drahcir495]

Originally Posted by countryjeep

Thanks a bunch! (and are you sure that wasn't Tim Allen??? )

Lol. No, it's his little known brother.

[Country Jeep]

Originally Posted by cj7xjmj

All the early AW4 transmisions came with the power comfort switch. This is not the towing package option. That was standard with the aw4.




Patrick

I would beg to differ, as I have already seen 5 86-88 Comanche's that did not have the power-comfort switch. And it wasn't just the switch that had been took out, but the transmission had no hook-up for the switch But cj7xjmj, can you give me reference to where you got the idea that the AW4's came standard with it?

Side note: 86 Comanche-Cherokee's did not come or have the option of the towing package/power-comfort switch.