MJ Comanche
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The Jeep Comanche (MJ) is a compact pickup truck that was produced from 1986 to 1992. The Comanche's design is based on that of the XJ Cherokee.
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Common Design
All MJs are built as a uniframe 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 come with disc brakes in the front and drums in the rear.
Also, MJs through all years are equipped with a height-sensing proportioning valve that is used to change the bias of the brakes if the bed has a load in it. It is used as an early anti-skid device.
For those curious of the differences in Cherokees and Comanches:
The taillight lenses are different from the XJ Cherokee, the front doors off of 4-door XJ's ('84-'92 at least) are swappable, hoods are swappable from '84-'92 models Cherokees (Cherokees above '92 used spring-loaded hinges), and all mechanical/electronic parts forward of the firewall are identical. There is a difference between the '86 and earlier hood catches and '87+ models (due to the introduction of the longer 4.0L I-6).
- The wiring harness is the same for the same year XJ up to the plug under the dash going back to the tail lights.
Body
The body comes only in standard size cab model (no extended cabs) with a rear fold down tailgate. Comes in longbed or shortbed two-tone versions. Longbed versions come with a larger gas tank than the shortbed. The gas tank is located in front of the axle on both longbed and shortbed models. The shortbed version was not available in 1986.
Interior:
Door panels are removable as stock. MJ bench seats and MJ bucket seats share a common floor bracket. MJ 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 speed sensor in the transmission instead of a cable.
Wheelbase:
Short Bed 2wd=113.1 4wd=112.9 (18 gal tank)
Long Bed 2wd=119.6 4wd=119.4 (16 gal [longbed] 23.5 gal [optional '86-'88; standard 1989+)
Dimensions:
Overall length is 179.3" for shortbeds, 194.0" for longbeds
Overall curb height is 63.7" for 2wds, 64.7" for 4wds
Track width is 57" with the 15x6 rims, 58" with the 15x7s
Body width at the rear flares was 71.7"
Length of inside of box at the floor is 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"
Essentially from the driver's door post forward they are the same as the XJ.
Engines
- 2.5L I-4 TBI (Throttle Body Fuel Injection) - 117 hp @ 5,000 rpm, 135 ft lbs @ 3,500 rpm - used in '86 and updated in '87-'90 to 121 hp and 141 ft lbs (2.5L I-4 became MPI in '91 and is rated for 130hp @ 5,250 rpm and 149 ft lbs @ 3,250 rpm).
- GM 2.8L V6 - 110 hp @ 4,800 rpm, 145 ft lbs @ 2,400 rpm - used only in '86, same as the engine found in the S-10s and Blazers. This is commonly replaced with the GM Performance Parts "crate engine" 3.4L V6.
- Italian VM 2.8L Turbo Diesel - 140 hp, 236 ft lbs - used in overseas MJs.
- Renault 2.1L I-4 Turbo Diesel - 85 hp @ 3,750 rpm, 132 ft lbs @ 2,750 rpm used '86-'87.
- 4.0L I-6 MPI "Power-Tech Six" - '87: 173 hp @ 4,500 rpm, 220 ft lbs @ 2,500 rpm, redline 5,000 rpm. '88-'90: 177 hp @ 4,500 rpm, 224 ft lbs @ 2,400 rpm, redline 5,000 rpm. These year 4.0Ls are commonly referred to as Renix powered.
- 4.0L I-6 MPI "Power-Tech HO" (High Output) - '91-'92: 190 hp @ 4,750 rpm, 235 ft lbs @ 3,950 rpm, redline 5,250 rpm.
Transmission Info
Manual Transmissions
Note: As of right now, I belive it was also found behind the GM 2.8L V6, and 2.8L Turbo Diesel. This info will stay here untill I can find hard proof that it was not used with these engines. Rusty 12:43, 17 December 2007 (CST)
- AX-5 5 speed manual - manufactured by Aisin-Warner - used '86-'92 with 2.5L I-4, 2.8L V6 ('86 only), 2.1L I-4 Turbo Diesel and 2.8L Turbo Diesel(export model).
- T-4 & T-5 manuals- Although not officially offered by Jeep, the T-4 (4-speed) and T-5 (5-speed) manual transmissions have been known to pop up in some 86 Comanches. The T-4 and T-5 is fully interchangeable with the AX-4 and AX-5.
- BA-10/5 5 speed manual - manufactured by Peugeot - used '87- Mid '89 with 4.0L I-6.
- AX-15 5 speed manual - manufactured by Aisin-Warner - used Late '89-'92 with 4.0L I-6. (Swappable into the 2.5L I-4 but the bellhousing will not fit the AX-5. There is a Dodge Dakota 2.5L I-4 bellhousing that will fit the AX-15)
Automatic Transmissions
- Torqueflight 904 3 speed automatic - manufactured by Chrysler - used in 1986 models only with 2.5L I-4 and 2.8L V6. It shares a bellhousing pattern with the Chevrolet 2.8L V6 (AKA 60 degree GM) and Cadillac FWD engines made after '89.
- AW4 4 speed automatic - manufactured by Aisin-Warner - used '87-'92 with 2.5L I-4 and 4.0L I-6. The bellhousing pattern is different between the 4.0L I-6 and 2.5L I-4, but the 4.0L I-6 pattern is the same as AMC V8s (it is NOT the same as any Dodge originally designed engine)
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
Suspension
The Comanche used the Cherokee's front suspension, with coil springs and upper and lower control arms. The Cherokee and Comanche were the first Jeeps to use this new "Quadra-Link" suspension. Coil springs allowed for greater ride comfort and axle articulation during off-road excursions. A track bar is used to keep the axle centered under the truck. Modified versions of this same basic suspension system were later used on the Grand Cherokee and the TJ Wrangler.
For the rear suspension, the truck uses leaf springs that are considerably longer than on Cherokees, which give Comanches good load-carrying capacity and a smooth ride. There is also a heavy duty "Big Ton" package available (known as the "Metric Ton" package outside the U.S.) for long-bed models. The package includes heavier-duty leaf springs, heavy-duty shocks, heavy-duty coils, the larger of the available wheels and tires and an upgraded rear axle, which increases stock payload capacity from 1,400 pounds to 2,205 pounds, well above that of any other pickup of the Comanche's size. In fact, a Metric Ton Comanche's payload rating is higher than that of many larger pickups.
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 - 2 types of rear driveshafts were used in MJs. Both were one-piece designs (as opposed to a 2-piece "slip" design like the front 'shaft) with standard u-joints at both ends and the slip yoke located on the output shaft of the transfer case. Some MJs had truly solid shafts, while others came with a "rubber-isolator" feature. This design incorporated an can-in-a-can design at the axle end of the driveshaft with a 1/4" thick band of rubber between them.
On '86-'92 models, the yoke slides in and out of the transfer case (or transmission in the case of 2wds) and is lubricated by fluid from the t-case or trans. Pulling the rear driveshaft off an MJ will allow fluid to pour out of the t-case or transmission.
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 (except the rare '86 models equipped with the NP-228 Select-trac transfercase which had non-CAD Dana 30s)
Rear Axles:
- AMC-20 - 29 Spline, one piece axle shafts, 8.875" Ring Gear; Metric Ton 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-'92 on some (not all) MJs equipped with towing-prep package and all MJs equipped with the Metric Ton package.
All rear axles are made of a spring under axle (SUA) design.
Gearing
3.07 - used with 4.0L I-6 engine / manual transmission.
3.31 - used with the rare "Fuel saver" package in '86.
3.55 - used with 4.0L I-6 engine / automatic transmission and with the 2.5L I-4 / 4 speed manual.
4.10 - used with 2.5L I-4 engine usually with 5 speed, also came with '86 Metric Ton models.
4.56 - rare but can be found on some older (~ '89 ~) models with 2.5L I-4 engine and auto transmission
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, but can be easily converted to open system with a '91 or newer radiator.
Airbags
No airbags during Comanche timeline.
Trim Levels
1986 - Custom, X, XLS
1987 - Base (SporTruck), Pioneer, Chief, Laredo
1988 - Base (SporTruck), Pioneer, Chief, Laredo, Eliminator
1989 - Base (SporTruck), Pioneer, Chief, Laredo, Eliminator
1990 - Base (SporTruck), Pioneer, Chief, Eliminator
1991 - Base (SporTruck), Pioneer, Eliminator
1992 - Base (SporTruck), Pioneer, Eliminator
Production Numbers
MJ (4x4 only)
SWB/LWB
1986 - xxxxx/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)
Phaseout
After the Chrysler buyout, the Comanche, like its brother Cherokee, received only minor changes, primarily those that would improve reliability and parts commonality with other Chryslers, but no major design changes. The lack of an extended cab body style, which all other compact trucks were offering by the time of the Comanche's debut, and the fact that the Comanche's prices were, in any given model year, higher than those of the top-selling American compacts (Ford Ranger and Chevrolet S-10), led to lagging sales as customers went elsewhere for roomier trucks.
As sales dropped, the Comanche was planned for discontinuation. A rumor existed that the Comanche would be replaced by a restyled Dodge Dakota (it's body-on-frame sibling from Dodge), but Jeep dealers disliked the idea because the Dakota was generally heavier and less reliable than the Comanche. The company chose instead to cancel the Comanche at the end of the 1992 model year, after only a few thousand trucks had rolled off the Toledo, Ohio assembly line.
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