Fun with an XJ

So my friend Eric (Ottawa here on the forum) has wide-ranging vehicular interests. We spend a lot of time tossing around ideas ranging from good to absolutely terrible.  A few years ago, I built him a custom Miata known as Project 707 that gets used for summer fun. He has a very late model Mercury Grand Marquis that is the big comfy easy button for cruising around. And after several years of looking at everything from desert race trucks to unmaintainable JDM weirdos, he's picked up an XJ to complete the GRM hat trick. Since I'm the wrench and I happen to live in rust-free XJ land, I picked it up and will be debugging the truck.

Meet the currently nameless XJ. A rust-free 1990 Cherokee Laredo. Some sunburned paint, unfortunate wheels and a few little problems that need to be sorted, it's a good base for a non-crazy build. The intent is to build something that's comfortable to drive around Ottawa's shattered streets, has character and can be taken to Moab or up in the Colorado mountains before he takes it back to Canada. It's not going to turn into a jacked up freak nor will it be covered in LED light bars. It'll probably stay on the current 29x9.5 tires because they're good ones and the size is just about perfect.

Why this vehicle in particular? Character. I'd actually stopped by the lot to look at a 1998 that was also there, but the crisper lines of the 1990 - inside and out - drew me to it. The fact that it happened to be in much better condition and selling for considerably less than other XJs in the area sealed the deal. It's only had three owners in its life and the first (and longest) seems to have been a fleet gig of some sort.

It also happens to be equipped with Selec-Trac, which means it can run in 2WD (snow hoon mode), 4WD with a center diff (responsible member of society mode) or 4WD with a locked center (Moab mode). Eric had been having trouble finding one with this transfer case, and it turns out that both of the XJs on that particular lot had it. I picked it up this morning and it got me to work, achieving the Minimum Vehicle Capability Requirement.

I'll let Eric jump in with the full spec sheet if anyone cares.

Keith Tanner said:

I'll let Eric jump in with the full spec sheet if anyone cares.

I care, I care, come on Eric, jump in!

Patiently waiting for more...

RossD said:

Patiently waiting for more...

Impatiently waiting for more in my case

Well, I have more for you but no pictures at this point. I shall get pictures. This is a very current build thread, I picked up the Jeep approximately 23 hours ago and I had to work yesterday.

We have a to-do list that's currently (checks) 43 items long. It starts with "buy Jeep", which is checked off. It includes things like "fill washer bottle because the light is exhibiting sloshing behavior" (now checked off) and "unberkeley front bumper" (bumper is currently still berkeleyed).

One of the things on the list started as "transmission kickdown", which I thought was just the cable. Any time you look for help on an XJ and transmission kickdown, master internet mechanics recite the procedure for adjusting the kickdown cable which has been credited with better performance, sharper throttle response, decreased overall pedal travel and probably shiny paint. Unfortunately, adjusting the cable, it does nothing.

Next step was to test the TPS. Now, this looks pretty new. It also has mismatched fasteners and the electrical connectors are ziptied together. Hmm. But the signal should be about 80% of the reference voltage at closed throttle and close to 0v at WOT. Checking it with a multimeter says it's 100% of reference at closed throttle and about 95% at WOT. A new $15 TPS is on the way, we'll see what happens.

Parts they are acomin' in. I shall share pictures and adventures when the time comes.

Did you know that you can put your VIN into Jeep.com and get the full build sheet for your vehicle? This is very cool, well done Jeep. Here's what was on the truck when it was built.

There are a couple of interesting things in here. First, it was given a fleet key and apparently sold to Midland Corporation. It has stiffer springs - I'm assuming from the spring group specification. It did feel stiffer than the 1998 I also test drove but I put that down to a set of totally blown shocks on the newer truck.

---------------------------

Equipment Listing

Vehicle Description

1990 JEEP CHEROKEE
STANDARD EQUIPMENT

Monotone Paint
Rear Fold w/Removable Cushion Seat
Passenger Assist Handles
4-Speed Automatic AW4 Transmission
Floor Mount Automatic Shift Lever
Dana M30/181MM Front Axle
3.55 Rear Axle Ratio
Tinted Windshield Glass
Front Door Tinted Glass
Tinted Rr Drs/Qtr/Liftgate Glass
Rear View Day/Night Mirror
85 MPH Primary Speedometer
Cigar Lighter
DESCRIPTION NOT AVAILABLE
Glove Box Lamp
Halogen Headlamps
Bright Windshield Moldings
Rear Qtr Solid Window Insert
Belt Moldings
DESCRIPTION NOT AVAILABLE
Rear Fascia Skid Plate Applique
EVAP Control System
20 Gallon Fuel Tank
DESCRIPTION NOT AVAILABLE
Power Rack and Pinion Steering
Standard Duty Shock Absorbers
Rear Shock Absorbers
Inside Mounted Spare Tire
Build To U.S. Mkt. Specifications
Payload Rating - 1800#
U.S. Dealer Retail
Zone 72-Portland

OPTIONAL EQUIPMENT
Cloth Low-Back Bucket Seats
DESCRIPTION NOT AVAILABLE
Heavy Duty Electrical Group
Trailer Tow Group
GTS Interior Package
Rubicon X
Laredo Decor Group
Power Equipment Group
DESCRIPTION NOT AVAILABLE
DESCRIPTION NOT AVAILABLE
4-Wheel Anti-Lock Brakes
Low Back Bucket Seats
Reclining Front Seats
Floor Carpet
Cargo Compartment Carpet
Cargo Tie Down Loops
Cargo Area Storage
Front & Rear Floor Mats
Spare Tire Cover
Cargo Compartment Cover
Full Length Floor Console
Overhead Console
All 4-Speed Automatic TransmissionsSelec-Trac
Full Time 4WD System
Dana 35C/194MM Rear Axle
DESCRIPTION NOT AVAILABLE
Front Left Side Sliding Window
Rear Window Defroster
Sun Visors w/Illum Vanity Mirrors
Entire Fleet Key Alike (FREQ 6)
Right Convex Mirror
Power Heated Mirrors
Remote Keyless Entry
Air Conditioning
Deluxe Insulation Group
DO NOT USE - See JP, KA classes
Digital Clock
Var Intermittent Windshield Wipers
Rear Window Wiper/Washer
Power Windows
Power Locks
DESCRIPTION NOT AVAILABLE
Headlamps On Warning Chimes
Courtesy Lamps
Ash Tray Lamp
Door Armrest Storage Lamp
Cargo Compartment Lamp
U/Hood, Removable/Rechargeable Lamp
Headlamp Off Time Delay
Fog Lamps
Bright/Body Color Front Bumper
Bright/Gray Mist Rear Bumper
Front Bumper Guards
Bronze Fascia Applique
Front License Plate Bracket
Grille-Black/Bright
DESCRIPTION NOT AVAILABLE
Roof Rack
High Altitude Emissions
Auxiliary Transmission Oil Cooler
Speed Control
Heavy Duty Engine Cooling
DESCRIPTION NOT AVAILABLE
All Radio Equipped Vehicles
AM/FM Cassette Radio
6 Speakers
Power Antenna
Leather Wrapped Steering Wheel
Tilt Steering Column
All Tires
Full Size Spare Tire
P225/75R15
OWL Wrangler AT Tires
15" Aluminum Wheels
All Aluminum Wheels
9 Additional Gallons of Gas
Rear Spring Group V
Left Front Spring Group Ix
Right Front Spring Group VIII
Special Discount
Midland Corporation

Interesting that it lists 'Full time AWD' as an option when you specifically said it was selectable.

Jeep considers the open diff setting to be Full Time. Locked diff is Part Time. At least, that's what it says on the shifter and the lights on the dash.

There is a center differential that is open in 4WD Hi Full-Time mode and distributes torque 48/52% front-to-rear. This mode can be used on dry pavement or slippery surfaces with only a small fuel mileage penalty compared to 2WD mode. In 4WD Hi Part-Time and 4WD Low, the center differential is mechanically locked, so these modes are for slippery surfaces only.  

Keith, I think its the other way around. I know I always guess the wrong way too. Full time is not fully in 4x4 mode, it's that is usable all the time regardless of road conditions.

https://en.wikipedia.org/wiki/Jeep_four-wheel-drive_systems#Selec-Trac

My '98 only had Part-Time 4x4 Hi.

Yeah, mine is part time only as it has no center diff. Going around corners on asphalt in 4wd is a interesting experience. I can almost feel the u-joints exploding. 

Interesting. I agree that "full time" should be with the open diff, but I had somehow assumed that the shifter went from most road to most off-road, which meant the "part time" was the road setting. But it's red instead of green, so that's a warning to people like me and there are probably mechanical reasons it works the way it does. Good thing I've been driving around in 2WD. My Land Rover doesn't have a center diff, so I know how the part time feels on grippy surface. Thanks for the correction.

In related news, an owners manual has been found on eBay

I was waiting at a traffic light a few years ago and heard the "ook ook ook" of big fat tires slipping and gripping on pavement. Turned to look and saw a Wrangler trying to turn a corner with the front diff locked. Plowed right into a car parked on the side of the road.

The Samurai was interesting with a spool in the rear and a Lock Right in the front. On a slick surface, in 4WD it pretty much went straight with the power on. It didn't hurt my feeling to go back to open diffs. Maybe one day a set of ARBs will go in. 

In reply to Keith Tanner :

I wasn't doubting you, it's just I've never understood the American definitions of AWD/FWD/Full time etc.  In the UK if it had the ability to send power to all 4 wheels in any format, we just called it 4x4, hence the old LAnd Rover slogan 'The best 4 x 4 x far' (although it looks funny with forum font)

IIRC AWD is always engaged whereas 4WD is switchable to some extent. I admit that I am not personally very invested in this particular distinction.

There's a "best 4 x 4 x far" sticker on the back of my Rover, of course.

Watching with interest. I'd love to have a beat up version of this to bash around the woods and backroads here. They seem to be the cheapest entry into usable 4x4 vehicle territory.

EDIT: so, dumb question...how comfortable are these for driving say...3-4 hours towing a 2000lb boat and trailer? Asking for a friend...

I use mine to tow the Abomination on occasion. That is in the 2700 pound range. The drivers seat isn't super roomy, but it's not a bad place to hang out. The brakes aren't super impressive so make sure your trailer brakes are up to snuff or drive accordingly. 

Full time means it can be in 4WD all the time, full time. That has a diff in the t-case. 

Part time is locked center diff

In reply to ultraclyde :

Regarding that last question. I had a 1996 2 door and a friend had a 1989 4 door. My '96 had a lot more room it felt like because the seat slid back further. The 2 door also has a bigger door. My XJ was also fairly comfortable on the interstate at 85mph but I never towed or took any long trips with it. It was a 2wd 4.0 auto. Fairly fun to drive. I miss it sometimes but not enough that I've tried to get another.

Interesting. I have noticed that the driver's seat doesn't go back very far on this four door. I was going to check to make sure the tracks weren't gummed up.

I like that 9 gallons of gas was an option. 

Project for the day: unberkeley the front bumper. 

There's a junkyard within spitting distance of my house that has a steel XJ bumper in stock, apparently. But before I took that drastic step, I decided to see what I could do about this.

I am of the firm belief that bumpers should be made of either chromed steel or unpainted plastic. They are to bump with. Anyhow.

I was chatting with Eric over Skype as I showed him pictures, and he felt that a new one was the way to go. I said "I'm going to strap this bastard to a phone pole".

He thought I was kidding.

That piece of steel happens to be a radiator mount I built for the V8 MG and later cut off for a different design. The circle of life. 

A little low range finesse, and voila.

Not perfect, so I broke out the fine adjustment tools.

Bolted on the new bumper end cap that I found in the back of the Jeep, and we're good. This was the first attempt to bolt it on. The second had it fitting much better to the body. Turns out these things were intended to be attached to the bumper off the car, access is basically impossible in situ. But I won.

Let's hear it for chromed steel bumpers that can be bent in and out of shape.

Then I needed to run some errands, and of course I took the XJ because it's new.

And I might have got a little distracted on the way to buy kitty litter. Yes, this is right near my house.

Naturally, I took some pictures for Eric.

And the obligatory rock parking shot.

The old guy seemed quite happy on the trails. Nothing extreme, of course, but definitely stuff that required ground clearance and a bit of flexibility. I wasn't taking pictures at that point.

If I lived there, I would constantly get "lost" on the way to get milk. 

It's a hazard.

Here's a little handheld video I shot for Eric after an attempt at a Skype video call failed. It's been heavily stabilized via software as it turns out I'm not good at holding an iPhone in one hand whilst trying to drive offroad with the other. It really has very few redeeming qualities but I'll share it in case anyone's interested in hearing me prattle on. Basil, BTW, is my 1967 Land Rover. 

The rattle you hear is the key chain banging back and forth. For some reason the video is tiny on GRM, click on the YouTube logo to embiggerate.