1987Comanche

The small case alternator is for non A/C trucks not equipped with HD cooling. The large case alternator is for all others. The larger alternator is a direct bolt-in replacement for the non A/C (non HD cooling) alternator though I did have to pry the U bracket open just a bit wider (1/4" or so) to fit it in. As a bonus the bigger case/higher output alternators are cheaper than the small case ones :clapping: Not only was it an upgrade but it was cheaper. How cool is that :)

I pulled a set of non-folding ones off a 94 or 95 XJ at the jy. They looked like they had never been disturbed until I removed them. :dunno:

If you use the clear faceplate from the idiot light cluster you can swap the speedo assembly and not have a hole. Your new cluster won't have a trip gauge but I don't know if that's important to you.

I changed all the lifters in my '87 2.5 without pulling the head. The pushrod holes are big enough to fish them out with the lifter removal tool. I think it took about 1.5 hrs start to finish. I examined the head on the '90 4.0 when I had the VC off. The pushrod holes are way too small.

Do they have this weight in non-synthetic? I have the early 4.0 head gasket oil leak and go through a fair amount of oil.

Query CCV instead of PCV. The Renix era 2.5 and 4.0 did not have a PCV system per se, rather they had a 2.4mm (?) "metered orifice." There was a TSB on the 4.0s on oil in the airbox and AMC/Mopar had a set of replacement hoses kitted to deal with it. Looking at the pic I bet one from a 4.0 would probably fit, or at least be close enough to make work.

The oil pressure on my '90 is about 8psi hot idle and 20-25psi at 2K RPM highway. I verifed the sender with a mechanical gauge and it's within 1-2 psi. I'd love higher oil pressure but she runs ok on 10W-40. Using 10PSI per 1K RPM rule of thumb I don't go past about 73mph (2300RPM on the tach). Been like that since the day I bought her...

Replace your turn signal sockets with later model XJ all metal sockets. When the ground on the OE plastic socket goes bad it grounds through the cluster, causing your turn signal indicator to stay on. You can either pull the tail light socket from an XJ (I think all years were metal tail light sockets) or find a '93ish XJ and pull the turn signal indicator lights. I did the driver's side 6 months ago and just spliced in a new pass side socket last week.

I bent and double flared a piece of brake line to replace the rotted spot on the AX-5 in my '87. Auto Zone carries a the full replacement line (clutch MC to the inlet you pictured) for the AX15/internal slave for around $30. A friend blew the line on his '90 XJ and I was surprised he could pick it up that cheaply.

It's a threaded sensor with 2 wires about 6" long and a connector, correct? If I remember my 2.5 correctly I think the sensor is identical to the renix 4.0 sensors. Is my description right? Can you post a pic of it? If it's discontinued I'd say e-bay or a post to the want ads. A CTS might work since the resistance is the same. I might have a spare 2.5 IAT in my basement come to think of it...

100% sure it's internal? My '87 4 cyl AX-5 had an external slave. Is the truck 2WD or 4WD? That will make a significant difference in labor to change an internal slave cyl.

Intake Air Sensor. On the Renix 4 Cyl it should be located on the firewall side of the intake manifold in a threaded port. It looks similar to the CTS but stays dry since it only measures air charge. There's a resistance/temp chart for it but basically the resistance should be pretty close to the CTS from cold start through about the 1st 5 min of idle. After that intake air temp and coolant temp start going their separate ways.

Hot engine with throttle fully open, correct?

I would think that a new bezel would have dowels, as long as its faithful to the OE mold. Really all you need is a donor XJ with an AW4 and a rear defroster or fog lights (power/comfort switch is on the right, fog lights/defroster on the left). If the factory installed switches they screwed them into the dash and never installed block off plates on the bezel. Thus the dowels are in perfect, untouched condition. What's your source for a new bezel? Do you have a pic of the rear of the bezel?

They're actually plastic welded in the bezel. If you use a soldering iron and a razor blade you can melt/break them out and reuse them in a new bezel. If you find a higher end bezel (wood grain for example) the block off plugs were never installed. you'll see a plastic dowel on the top & bottom of each hole. Clean out the appropriate holes in your block off plate (may need to drill and open them up since it was installed once) and make sure it slides over the dowels freely. Hold the block off plug snugly against the bezel and use the soldering iron to melt the dowels. Now you've successfully plastic welded the block off plugs into your new bezel :clapping: I installed a wood grain bezel in my MJ about a year ago and the above worked great.

Putting in the Grand Am GT seats was more work than the standard XJ bucket swap but they're quite comfy. :clapping: The hardest part of swapping any seats in is trying to figure out: 1. if they'll fit and 2. what adapters you have to make. The GT seats were a good choice b/c they have 4 symmetrically located bolts that secure the factory seat tracks to the steel seat base. I ended up drilling and bolting 2 pieces of plate steel to each base, then installing the MJ seat brackets in the truck. I placed the seats on the brackets and marked where to drill the plate steel. I ended up having to raise the seats with 1" spacers as the trans tunnel in these trucks is huge. The seats were perfectly located except for the fact that I couldn't close the door. Raising them 1" allowed me to slide them over just enough to clear the doors. Here's a pic of what I ended up with:

The '91 at LKQ in Greenville, SC had a completely intact rear (4.0, AW-4, what ratio is that?). It's kind of a haul from Toccoa but you could go, pull the rear, and be back on a Sat.

This was at LKQ Greenville, SC last week. It's a '91 and the bed is beautiful...too nice to be crushed!! The truck came in on 1/18 so it's slated to be crushed within the next week or two. I think they want $150-$175 for the bed. I'd go back for it but I don't have the time.

I'm in the process of boxing up the 4.0 HO sending unit so I can mail it out and I thought it might be worthwhile to dig out my spare Renix 4.0 sending unit and take a few side by side pics. HO unit is much cleaner, has the orange paint on it, and you can see the wire grid on the sending unit. Hope the pics help someone out!

So after owning 2 MJs and being on the forum for 4 yrs I figured I should finally post a few pics of the trucks, current and former. First off, the current ride: Maura: 1990 Renix 4.0, AX-15, NP231. Picked her up with 117K on the clock, not running (electrical problems), leaking everything, filthy interior, steelies with bad tires, and had every dents on panel on the pass side (bed, cab, door, fender). The PO said he slid off a dirt road into a strand of trees :dunno: I'll have to list all the mods later but I've used mostly XJ/MJ components except for the 2002 Grand AM GT seats and S-10 coolant overflow tank. I don't have any before pics but I believe my '87 can fill in quite nicely. I swapped the ratty front bumper, some interior parts (cluster, headlight delay module, etc) steelies, and cap from the '90 to the '87 and then sold the '87. The '87 was a Renix 2.5, AX-5, 2WD with the factory black interior and no A/C (originally from Indiana). I miss that truck but trading up to a 4.0 4WD with 80K less was too good of an opportunity to pass up. I should have taken pics of the two side by side but I had very little time available when I got the '90. Here's a few pics of the Meg: my old '87: I'll try to add more info later on.

'91 4.0 HO, AW4, 2WD, column shift auto, grey bench, A/C, 165K on the clock. Was originally white but someone painted it purple!. Excellent body, however. Currently at a JY in Greenville, SC but will be crushed around 4/20/11.

I worried about mine initially too ('90 4.0). I upgraded to a newer style valve cover with better baffles, made sure all the ccv lines were clean and it made a marginal difference. Ultimately I bought a cheap Fram Air Hog (their version of the K&N) and check it every 8K or so. The thing is completely oil soaked but since it's gauze it won't fall apart on me...it probably weighs 3 lbs by now. The oil coming out of the airbox on the Driver's side nicely balances the oil leaking from the head on the pass side.

Google "Leon Miller, Wagonmaster." He's the guy who's responsible for the run up in Grand Wagoneer prices.

The only thing I pulled on my '90 4.0 4X4 was the starter. I thought it was easier to break the pan loose, drop the oil pump into the pan (pump is only held on with 2 bolts) and roll it out with the pump inside.

Link explains the function of the secondary O2 sensor as well as the possibility of an O2 simulator. Since you're vehicle is pre-96 you'd probably be ok but check with the emissions gurus to be sure. http://www.o2sensorsimulator.com/