Eagle

Not looking to tune anything. I'm looking to eliminate a driveability issue.

Probably not so odd. The factory really didn't want to build any 5-speed manuals in model year 2000. When I went into the dealer to order an XJ to replace the [bleep] [bleep] [bleep] '99 WJ Grand Cherokee, the factory wasn't taking any orders for 4.0L manuals, so I ordered a Classic with automatic and Selec-Trac. This was in October of 1999, and the vehicle showed up in November. That one was turned over to my wife when I married her in 2003. Somewhere along about January of 2000 I was in the parts department picking up something, and the sales manager wandered through. He knew I had wanted a 5-speed, so he mentioned that the factory was accepting orders for 5-speeds. 'But I guess you don't need one now," he said. "Wrong," says I, "let's fill out an order." So we did. And then I waited ... and waited ... and waited some more ... and waited still more. Whenever I checked, the order was still sitting there but no build date had been assigned. Jim, the sales manager kept asking if I wanted to cancel the order, and I kept on saying no. So we waited ... and waited ... and waited. Anf then one day around late April, if I recall correctly, he said they had a build date. It looks like they waited until the very tail end of the 2000 model run and then did a short run of all the 5-speed orders. I could look up the date, but I think mine finally arrived in June. So it wouldn't surprise me if it's a bit of a mongrel, built from whatever parts they happened to have on hand. Where did you find that info? That part number doesn't show up in my parts manual.

Got it: 56041 668AF Which is interesting, because that part number doesn't appear in my 2000 XJ parts manual. It also doesn't appear in the 1999 or 2001 XJ parts manual.

All I can make out at night, with a flashlight and inspection mirror, is 956041. But they all start with that, so I'll have to look again tomorrow.

To be honest, I very likely won't ever finish it. Too many things have gone wrong in life since the project began. But it's still a possibility, which is why I'm not releasing any excerpts I share into the public domain.

Correct on the change between 1989 and 1990, but it's not just the calipers. There are several permutations and combinations that all have to match up. The floowing is from the book I started to write several years ago. It is copyrighted, and by posting it here I do NOT grant permission for anyone to reproduce it or to distribute it. - - - - - - - - - - - - - - - In general, the parts to be concerned with in keeping the front brakes compatible are the steering knuckles, the hub/bearing assemblies, the rotors, and the calipers. (There is a more complete enumeration of the interrelationship of these parts in Chapter 6, Axles.) Only two steering knuckle designs were used: 1984 through 1989, and 1990 through 2001. Left and right side knuckles are different part numbers within each group. Three different hub/bearing units were used. The hub/bearing units are the same for both sides of the vehicle. The different years for hub/bearing assemblies were: 1984 through 1989; 1990 through mid-1999 (composite rotors); and late-1999 through 2001 (cast rotors). Three rotor types were used: 1984 through 1989; 1990 through mid-1999 (composite); and late-1999 through 2001 (cast). Only two caliper types were used: 1984 through 1989, and 1990 through 2001. Left and right side calipers are different part numbers within each group.

Not true. We want zero toe-in -- when the vehicle is rolling down the road. We set it for slightly more because once the tires start rolling and encounter road resistance, that resistance takes up all the slop in every tie rod and joint in the steering mechanism. Way back when I was in my teens (around the time they signed the Magna Carta), the good front end shop in town used a spring loaded spreader bar that fit between the leading edges of the two front tires to force them out, simulating the real-world rolling condition. Otherwise, if we set it for zero in the driveway, on the road that built-in slop will allow the tires to splay out, and then we have toe-out -- which is what we DON'T want. Yes, tire size affects toe-in, because what we're really looking for is an angular measurement. In the old days, it was just easier to express and measure it in inches. IIRC, the 1988 factory service manual for the XJ and MJ give the alignment specs in inches (fractions). The FSM for my 2000 XJ gives the specs in degrees, which are independent of tire size. But if we're doing it at home, we're not set up to measure angles so we use a tape measure. And if we're doing it with a tape measure, the larger the tires, the greater difference between the front and rear sides of the tires for the same angle. I've never rolled on anything larger than 31x10.50s and I still regard 1/8" of toe-in as the maximum I want to see. When I'm doing a shade tree alignment, each time I make an adjustment to the toe I roll the vehicle back a car length, then roll it forward again. This allows the tires to "sqirm" into the new alignment, so my measurement isn't fighting sidewall tension created by making an adjustment while the tread contact patch is firmly planted on Terra firma.

Spacers in the rear have nothing to do with front toe-in, and you don't add or subtract anything based on the rear. You measure the distance between the centerline of the front tires at the front, and again at the rear of the front tires. If the number from the front of the tires is larger, you have toe-out; if the number at the rear of the tires is larger, you have toe-in. The theortical ideal is zero, but in the real world you should aim for about 1/16" with 1/8" being the max. You do NOT want toe-out.

Definitely not rusted away. It only has 41,000 miles on it, and has spent most of its like garaged. And this problem has been there since I drove it home from the dealership, new.

Thanks but neither suggestion fits the symptoms. This is basically that the slightest lifting of pressure on the accelerator peddle is like shutting the engine off -- completely.

It happens at pretty much all RPM ranges.

My foot is on the accelerator peddle, not the slip yoke. I know what you're referring to, my late, unlamented '99 WJ had that. This it totally different.

I have one of the extremely rare 2000 XJs with a 4.0L engine and 5-speed. I believe mine is the only one in Connecticut, and I've been told it's one of only two in all of New England. I've had a problem since it was new, and it's getting aggravating enough that I'd like to fix it. I've been driving standard transmissions for over 60 years, and I've always considered myself to be a "smooth" driver. I don't slam shifts, my clutches last forever, and my passengers don't complain that their heads are being snapped off at the neck by the way I drive. Except ... in the 2000 XJ. It's impossble to drive smoothly. Example: Say I'm on a level road at 55 MPH. I come to a slight downgrade and speed increases, so I want o ease off the throttle just a bit to maintain 55 MPH. Can't do it. No matter how gently I try to ease up on the peddle, as soon as I start it's like the engine shuts off, the driveline lets out a loud clunk, and I'm slowing down. So now I need to apply juuuuust a little bit more throttle to get back up to 55 MPH. Nope -- same thing. No matter how gently I try to squeeze on the throttle, it comes in with a bang and a lurch. It's very annoying. I had the dealership look at it a couple of times while it was under warranty and they couldn't find anything wrong, sio I've been living with it. But it's not right. I want to fix it. I thought it might be the TPS, but the 2000 XJ FSM doesn't have any information about adjusting the TPS. They tell me how to replace it, but no mention of an adjustment. Does anyone know if it can be adjusted? If so, how?

That's the problem, then. Under light throttkle the engine has enough vacuum to hold the actuator doors where you set them but when you accelerate or go up an incline, as you know the throttle opens and the engine vacuum drops. The canister is a vacuum reservoir to maintain vacuum under those conditions. You can get a canister from any wrecked XJ. There are two types -- the ones with cruise control have two chambers, one for the HVAC and the other for the cruise control. If your truck doesn't have cruise, you can use either type.

The problem is almost certainly where the vacuum line runs from the vacuum reservoir behind the front bumper under the battery tray. The hose deteriorates, a vacuum leak developes, and with no (or low) vacuum the vents default to the defrost position. It could also be a leak in the reservoir canister itself.

I've considered trying to carve those out of hockey pucks ...

Yes, but the 2.8L V6 didn't use a crankshaft position sensor. The '87 2.5L used the Renix throttle body injection system and it uses the same CPS as the Renix 4.0Ls.

Where did people get the idea he has a 2.8L? He has stated that he has a 1987 2.5L 2WD. That means whatever he uses has to have provision for a CPS, and the flex plate has to be Renix-compatible. Are we all on the same page now?

A 2.5L XJ will probably have the Chrysler 904 automatic transmission. I don't think that used a TCU. It'll work in an MJ, but I don't think MJs used that transmission.

Been there, done that. I keep a half dozen sets around, some sized for the D35 and some for the D44.

This is looking more and more like one of those situations where everyone "knows" it shouldn't be done, but everyone has a different reason. What I know: I have reused factory u-bolts on several vehicles, including my race car back in the 1970s, without having any problems There must be dozens of people who have done the added main leaf AAL budget boost in XJs, and I'd bet that none of them bought new u-bolts The new u-bolts I see in the parts stores look to be 3/8" or 7/16", max, and I'm sure they're made in China. MJ factory u-bolts are 14mm (.5512", which is close to 9/16" - .5625"). I would much prefer to take my chances with used 14mm u-bolts than play around with Chinese replacements that are of questionable steel, and smaller to begin with.

https://www.eng-tips.com/viewthread.cfm?qid=256363

Great trip. I really like the early photos, in the Rockies. Spectacular scenery. I need to scare up the $$$ for another road trip.

Because if I'm going to pull parts off the hulk in the back yard, it helps to know which part is needed, and I can't see the part numbers when the parts are on a wreck. Follow the discussion, Donald.