Eagle

You are correct. But, does 60 cycles (Hertz) per second translate directly into something we can use to assess the calibration of a tachometer? IMHO, not directly. The power is 60 cycles per second. As you note, this is 3600 cycles per minute. But ... 3600 cycles does NOT equal 3600 RPM. A 6-cylinder engine fires 3 pulses (cycles) per revolution, so 3600 cycles ==> 1200 RPM. A 4-cylinder engine only fires 2 pulses per revolution, so 3600 cycles ==> 1800 RPM.

Cool -- I never knew that. Of course, that just confirms operation, it doesn't address calibration. (Or does it?)

It's not a screw, it's a potentiometer.

Doesn't the AX-15 have a larger input shaft? That means you can use the 2.8L pressure plate, but the disc (the part that engages the input shaft) will have to be something that will fit the AX-15 tranny.

I've always used air.

Your opening post said the tach does return to zero. Which is it? Yes, or no?

^^^ Ditto. Can't send you a PM -- is your inbox full?

No.

What year is the XJ?

287,000 on my '88 XJ. It was my daily driver until a fuel line ruptured underneath. Once I get that repaired, I expect it to be my daily driver through the winter. My goal is to make 300,000 -- after that, we'll play it by ear.

Dunno, but valve seals (which aren't really seals, but "deflectors") are cheap and a lot easier to install than doing a tear-down. Give it a try.

Rancho lists a "full-length" add-a-leaf kit for the XJ (Cherokee) and MJ (Comanche). Of course, it won't be full-length in a Comanche, but it will be "long" rather than "short." The Rancho catalog says it generates 2-1/2" of lift, but that's the XJ spec. In the MJ it's more like 1-1/2". I used a set on a '78 full-size Cherokee that was badly sagged in the rear, and it brought things back to a bit higher than stock height -- which allowed me to get 31x10.50s onto the drums without having to jack the body away from the axle. Should run about $80 at today's prices, I think.

^^^ This. Think of it this way: All the tachometer really does is count ignition pulses. For a 6-cylinder, it takes 3 pulses for one revolution. For a 4-cylinder, it only takes 2 pulses for one revolution. So at 1000 RPM, the 6-cylinder engine generates 3000 pulses. The 4-cylinder engine only generates 2000 pules at 1000 RPM. Put a 4-cylinder tach into a 6-cylinder vehicle that idles at 1000 RPM, and the tach will report those 3000 pulses as 1500 RPM all week long.

:doh: I knew that -- I was just testin' ya ... yeah, that's it, just checkin'

Withdrawal (especially forced withdrawal) is tough. Got up Friday morning, checked e-mail and weather forecast as usual, and went out to a meeting. Came home around noon to find no Internet. Called AT&T technical "service" and was told they would have it fixed within four hours. Okay. Went out again. Returned home around 4:30 p.m. to find a message on my answering machine telling me my DSL connection had been repaired. Happy. Went to the computer and fired up my browser. No Internet. NOT happy. Called technical "support" again, and was told it would be fixed within four hours. 9:00 p.m. came and went -- no Internet. Called technical "support" again, and was told it would be fixed by 3:30 a.m. Woke up Saturday morning -- no Internet. Called tech "support." Now they tell me there's a general outage in my area, but they can't predict when it might be repaired. They said they would call me back between 11:00 a.m. and 1:00 p.m. with a status report. I went out to use the free Wi-Fi at McDonald's. Came back around 4:00 p.m. -- no Internet, no phone message. Multiple calls later, still no useful or comforting news. The second-to-last technical "support" person I talked to had a heavy Indian accent, but he claimed to be in California. They don't even know where they are supposed to be, because earlier a different tech "support" drone told me the support office is in the Central time zone. Around 3:00 p.m. on Sunday I called again. This time I got a young (sounding) female who mercifully did not have an Indian accent, and who was at least pleasant and seemed genuinely apologetic that I'd been without DSL for over 48 hours. But -- she still couldn't tell me when I could expect to see a resolution. It's now 7:00 p.m. on Sunday and I have Internet. My relief is palpable.

??? Did you replace the drive shaft u-joints, or the front axle u-joints?

As far as I know, the ratios for gears 1 thru 4 are identical. The only difference is that the 5-speed has 5 speeds. I would just swap the bellhousings and use the 4WD setup.

That's much too high. It should be 30, or maybe even 28. According to my '88 MJ factory service manual, the recommended tire pressure is 30 psi for sizes P205/75R15 through P225/75R15 ... and 33 psi for P195R15 The door jam on mine says to use 30 psi for P series 215/75/15s. I have done that for the past 150K with good luck , but with these 6ply rated tires, I am considering going up a bit on the pressure to allow me to take advange of the stiffer sidewalls.....not to the 52 psi they will take but up a little bit to about 35 or so. "P205/75R15 through P225/75R15" includes P215/75R15 -- it's right between 205 and 225. With a stiffer sidewall, you need LESS pressure to keep the tread patch flat on the ground. All you are going to do running higher pressure is to cause the center of your tread to wear down before the shoulders.

I had no issues (other than the steering wheel centering) when I installed the newer style track bar in my '88 XJ. I also put one in the '88 MJ after I tossed the Rusty's adjustable.

That's much too high. It should be 30, or maybe even 28. According to my '88 MJ factory service manual, the recommended tire pressure is 30 psi for sizes P205/75R15 through P225/75R15 ... and 33 psi for P195R15

No difference. There was a part number change somewhere around 1990 or 1991, though, and that made a difference. The old part number was superseded, so they only sell one, and both I and the parts guru at my dealership assumed (we all know how dangerous that can be) that the difference was that the frame end on the newer ones has a zerk -- the original track bar on my '88 didn't have a zerk. However, when I installed the new one, my steering wheel was suddenly about a quarter turn off center. Easy enough to adjust, and I don't see visual evidence that the axle is off center, but it DID move. But nowhere near 3/4 of an inch.

AutoZone or Advanced Auto will generally "rent" you tools like a ball joint press for nothing. You give them a security deposit, take the tool home and use it, and you get your money back when you return the tool.

I can't recommend Rusty's. I put one on my '88 MJ and the upper end (which fortunately is replaceable) only lasted a year. A friend from NAXJA had worse luck -- the threaded bung that the upper TRE screws into pulled out of the tube. Just like with Rough Country ... "don't even bother."

Clogged catalytic converter?

They do have to be pressed out. Everyone I know uses a vise and a socket.