AZJeff

The proportioning valve also contains two features mandated by Federal motor vehicle safety laws: 1. a design that separates the front and rear brake systems so that one system can be open (leaking) and leave the other system capable of providing braking function. This is accomplished by having a separate piston and output for the front and rear brake systems in the MC, and they are routed to the prop. valve and theron to the wheels. 2. an electrical switch on the prop. valve that will close to turn on a light on the dash when one of the two systems develops a leak that causes an imbalance in pressure from front to back. The prop. valve also will restrict/reduce pressure to the rear brakes to prevent premature locking of the brakes due to excessive line pressure to the back. It does this with a spring and and O-ring inside the valve, and is normally NOT adjustable. The fact that you are opening the fronts and getting them to virtually shut off makes me think your prop. valve is defective. Either it's gunked up, or missing it's O-ring, or missing it's spring.

There is also a trim cement made by 3M that can be used to attach some moldings. Most auto parts stores that carry body repair stuff will have it. It works well on pieces of trim that are lack openings or irregular shapes in them. Things like letters spellinig a word (J E E P, for example) don't do well with this stuff, but if you are attaching something like "4.0 Litre", then it works perfect.

You wind the award for this year for finding the most hillbilly auto repair done by a previous owner!!

I am a firm believer in doing both when I see one that is worn. I do this on brake calipers, wheel bearings, shocks, springs, and any similar "paired" items. Besides, Amazon only had the carrier bearings as sets of 2 anyhow, so I will do both.

Thanks, Eagle. I did some searching on the interweb, and found that, as long as the carrier is going into the same housing from which it came, the chances are good that all would be well with new bearings. Let's hope it turns out to be true!

While putting new axle seals in the front of my MJ, I discovered that one of the carrier bearings is toast and is going to need to be replaced. Here is my question: If I replace the bearing/outer race, what are the chances that the preload and backlash will be within the original factory spec.? I am hoping I can just remove the old bearing, install a new one (using the same shim stack) and be within desired specs. Am I being unrealistic?

Motor mounds and transmission mounts have nothing to do with death wobble. In fact, bad motor mounts can be diagnosed really easily with the vehicle sitting still and having a helper "load" the engine with the transmission in gear (and the parking brake or service brake applied FIRMLY). While the helper is doing this, you are examining the motor mounts for severe distortion of the cross bolt in the rubber. It should move some, but NOT to the point where it reaches the outer part of the mount. I suspect you still have a front suspension issue if you are experiencing TRUE death wobble. Your description of a pothole or a "wave in the road" triggering the behavior is CLASSIC death wobble symptoms.

My address is in the area that requires an emissions test. If I lived 2 miles east of here, I would be exempt. Since I am not roadworthy right now without brakes, I am not too concerned yet. I will probably take it in and have it tested with just the front two California cats, and see if it passes. I will also investigate the exemption mentioned in the link by "Ohm" Standby for more details later.

A new MC will require a bench bleed to get things started. Now that your vehicle has the height sensing valve bypassed, just bleed the brakes like a "normal" car. Pro-Tip: On vehicles as old as ours, pulling a power booster from a boneyard is an iffy proposition. The rubber will be dried out and possibly cracked, and the booster may not work as intended. As financially painful as it is, a reman'd booster is a much safer bet.

For those of you who have never experienced death wobble, or are not sure what is actually LOOKS like from the outside, there are some videos out there showing the shocking behavior. Here is a good one:

If there is such a thing, there is no information on it anywhere on the Arizona DMV or Arizona Dept. of Environmental Quality websites. I cannot find any exceptions for vehicle age, etc. and I am unlucky enough to live in an area of this state that requires emissions testing.

Overheating at higher road speeds is almost always a sign of one of two things: 1. poor water circulation due to a worn water pump 2. blocked radiator passages

ADAPTING A 2004 DAKOTA TANK INTO A SHORT WB COMANCHE I have attached a write-up on how to adapt a Dakota fuel tank into a SWB Comanche. It should be applicable to a LWB vehicle with minimal changes. MY ADAPTATION OF A 2004 DAKOTA TANK INTO A SHORT WB COMANCHE V2.pdf

No, not yet. I have been debating this myself. Maybe when they "sniff" the unit (which is registered as a 1989), they will find it complies. The only thing stopping me right now is that the vehicle has no brakes, and I am waiting for parts to arrive to complete that task. Maybe I will take it to the emissions test station and see how it goes....

Thanks, "JeepDriver" and "Sinkrun" Those two details explain a lot that seemed a little unclear from the FSM. So it looks like I have all of the O2 sensors and wiring needed, along with the mini-cats. What I don't have is the "main" cat located downstream between the trans. mount and the muffler. I guess I have some shopping to do if I want to pass an emissions test.

A V6? A 2000 XJ never came with a V6, only the 4.0 in-line six. My FSM lists the following codes: P0143 (M) 1/3 O2 Sensor Shorted To Ground P0144 (M) 1/3 O2 Sensor Shorted To Voltage P0145 (M) 1/3 O2 Sensor Slow Response P0146 (M) 1/3 O2 Sensor Stays at Center Since they talk about O2 sensors 1/1 and 1/2, as well as 1/3, I thought it might be a sensor related to a third cat. I am still confused.

Nobody knows? Eagle, you are a wizard on XJ's as well as MJ's. Do you have any clue, or know anyone on other forums who would know?

My MJ has the engine from a 2000 XJ in it, and it has the California emissions system on it. I see two "mini-cats" just off the exhaust manifold, with pre and post cat O2 sensors. What I do not have is a second "main" cat converter further downstream. The FSM is contradictory here. It shows a main cat like all the "49 state Federal" in place along with the mini-cats, but the wiring diagrams do NOT show O2 sensors associated with the main cat., only with the mini-cats. So do the CA XJ's have three cats? If they do,does the main cat have any O2 sensors? i have to get the exhaust system right to pass emissions testing here in AZ.

Dumb idea---binding of slip yoke on the output shaft?

PERFECT. Thanks for the explanation.

Being a retired mechanical engineer, I found that little discussion really interesting, and it backs up the "rule of thumb" stuff we have all heard about U-bolts on leaf springs.

I am reading the interior on my MJ, and part of my planned improvements is the foil lined insulation matting glued to the inside of the roof above the headliner, and on the back wall of the cab behind the carpet panel. Most at of your added heat comes from solar input, and while tinting the windows helps, adding thermal insulation in the roof in particular is really key.

Thumbs up to Dzimm on this topic. He knows his stuff on this area, and helped sort out some fuel tank conversion issues for me.

I see listings for front calipers up to the 1989 model year, and another listing on parts sources for 1990 and beyond. what visual clues are there to ID the differences between the two variants of calipers, so I can know which version I need?

Here is a good way to check for throw-out bearing noise: when engine is running (and making the whirring noise you report), LIGHTLY apply force to the clutch pedal, just enough to load the throw-out beaing against the clutch pressure plate assembly. If the noise changes in tone or volume, then it's the throw-out bearing that is your problem.