Eagle

You mean you drilled a new hole? All that does is move the axle slightly toward the passenger side. It doesn't change the alignment.

I agree with Comanche09 -- that's not a 1990 gauge cluster. That's an early cluster and the speedo cable connection is probably different. Only a photo os the back side will tell for certain.

I used to run a Meyers plow on my old full-size Cherokee with the 360 V8. I had the same problem. It's pretty fundamental -- engine cooling requires air flow through the radiator, and putting a solid object in front of the radiator doesn't enhance the air flow. I never found a true solution that would allow me to drive around with the plow on as if it weren't there. The only things that helped were keeping the plow as low to the ground as possible when driving, and driving slower. I sold that rig more than 10 years ago so I'm digging deep into the dustbin of memory, but IIRC the critical speed was around 40 MPH. As long as I kept the speed under 40 MPH the temperature stayed under control. Once I went over 40, it overheated. Period, end of discussion.

What is the caster angle? What is the toe-in?

Then that's the difference.

Did the 98 ZJ still have a distributor? I'm pretty sure the 99 WJ had individual coils on each spark plug. That might be the difference.

White is positive 12v to the light bulb. Black is ground. Red is positive 12v to the tach Green goes to the negative terminal of the ignition coil. (Or to the tach output in the yellow diagnostic connector under the hood.)

A potentiometer isn't a switch. It's a mini-rheostat. Turning it changes the resistance through a range. To calibrate it for a different cylinder count, you have to to have the cluster connected to the wiring harness and also have an idle tachometer attached to the engine (or use an optical sensing tachometer) to tell you the correct reading. Then you turn the potentiometer (or "pot," for short) until it agrees with the reference tach reading.

It has full gauges. The police packages don't have a tachometer because they don't need one. They were all automatics, and police have other things to worry about than how many RPMs the engine is turning.

Just for the record, the temperature sensor on the lower front of the block is for providing data to the ECU and has nothing to do with what reading you get on the gauge. The sender for the gauge is the one of the left rear corner of the head.

There is a potentiometer on the back of the cluster, next to the tachometer. It's a small, round thingie (technical term) with a plus-shaped recess in it for a Phillips screwdriver. I don't remember which way you have to turn it to go from 4 to 6 cylinders or 6 to 4.

If you will be replacing the springs anyway, get new springs for the amount of lift you want and get rid of the extended shackles. Extended shackles are what killed your springs.

Because the XJ uses dedicated amber turn signals in the rear, independent of the brake lights, whereas the MJ has both bulbs on each side doing double duty as brake & turn signal lights. When the same bulbs are doing both jobs, you need a logic module to make a third brake light function properly.

As long as the years are compatible, all you have to do is unplug the wires from the stock gauge cluster, plug them into the new full gauge cluster (should be in the same exact places), and the tach will work fine. Doesn't matter if the donor vehicle has a different engine from yours. As I said earlier, I have an '88 MJ 4-cyl, got a full cluster from an '87 XJ 6-cyl, plugged in the wires, and the tach, speedo, fuel, and volt gauges worked fine. You have to replace the senders for the water temp and oil pressure with senders for gauges (stock senders are for idiot lights). Once you replace those senders, all the gauges will work like they're supposed to. Easy... If the tach came from a vehicle with a different number of cylinders than the truck into which you install it, you have to recalibrate the tach or it'll be off -- by a lot. Think about it -- the tach counts ignition pulses. In a 6-cylinder engine, there are 3 pulses per revolution. For a 4-cylinder, there are two pulses per revolution. Put a 6-cyl tach in a 4-cyl vehicle and the engine has to go around one and a half times (3 pulses) for the tach to register one revolution. Which means your engine is turning 50 percent faster than what the tach reads. (2000 RPM on the tach ==> 3000 RPM at the engine, 4000 RPM at the tach ==> 6000 RPM at the engine.) Recalibrate.

The stock studs don't protrude enough? What's wrong with the tech people? The only threads doing any work ar the threads that engage the threads in the lug nuts. Anything outboard of that is wasted metal. If you have a wheel that loosens up enough that the lug nuts are unscrewing themselves from the studs, that extra length isn't going to help you one bit. Idjits.

31 x 10.50s will fit the Jeep 15 x 7 rims fine. It's the base model 15 x 6 rims that they should not be used on.

WANT!

You don't need a test light to see if you're getting spark, but the engine has to be tirning over (cranking) in order to do that. Is the engine turning when you try to start it, or not?

Eagle, did you ever see the old magazine review of a hump-nose Javelin (71-74), where the axle sheered in half as the reviewer pulled away from a stop light? :eek: The rest of the review didn't go so well after that. :rotfl2: No, I pretty much stopped paying attention after 1970. The newer, bulbous style Javelins were fugly and oversized, with no increase in interior space. Plus they dropped the 2-seat AMX.

My '68 Javelins had the springs under the axle. Also, they had the hub slined to the axle, which is the weak setup that's prone to shear off. The MJ AMC 20 had one-piece axle & hub assemblies. Also, your math is wrong. With 235s, 4.56 gears would turn 2873 RPM at 70 MPH, and 4.10s would turn 2583 RPM.

current: 1986 LB 2wd 2.5L manual base 1987 SB 4wd 4.0L manual Pioneer 1988 SB 2wd 2.5L manual SporTruck 1988 SB 4wd 4.0L manual Chief 1989 LB 2wd 4.0L manual Pioneer Past: 1986 LB 4wd 2.5L manual don't know 1986 LB 4wd 2.5L manual XLS (?) 1987 SB 2wd 4.0L manual don't know

Lift also results in less caster. Positive caster is when a line drawn through the lower and upper ball joints leans back toward the top, negative caster is when that line leans forward at the top. The stock configuration results in around 7 degrees of positive caster (upper ball joint is behind lower ball joint, line leans back at the top). If the caster gets less than 4 or 5 degrees, there is less tendency for the weight of the vehicle on the tires to keep the wheels tracking straight, and to self-cancel wheel shimmy. If wheel shimmy is not cancelled out and can be transmitted from one wheel to the other, you get death wobble. This is why lifts require longer control arms, and why adjustable control arms are better if you want to be able to fine tune your alignment. The Catch-22 is that when you have a big lift, cranking the caster back to 7 degrees or more results in the u-joint angle at the front pinion becoming excessive, which causes rapid wear of the u-joint as well as vibrations. So it becomes a bit of a dance -- you have to try to find the compromise between caster angle and u-joint angle that prevents death wobble while not eating u-joints for breakfast, lunch, AND dinner.

Heims are open and attract dirt, which greatly accelerates wear. They are great for specialized applications such as racing, but not recommended for general duty such as street driving. They also are less than ideal for a veicle that will be running in dirty conditions -- i.e. off road. Racing teams figure on replacing them after every race (or two). For the rest of us, TREs are a better choice.

Hold on ... How can death wobble be worse than before? Are you sure you have DEATH WOBBLE, and not just wheel shimmy? Death wobble is when BOTH front wheels start shaking so violently that you can't steer the vehicle and you can't keep driving because you're out of control, and you have to slow down to almost a complete stop before the shaking goes away. It is named "death wobble" because when it occurs you KNOW you are going to die, right now! If your life didn't flash in front of your eyes and you didn't pee in your pants, it wasn't death wobble.

Two words: WHEEL + BALANCE