RLCollins

What temperature thermostat would you install next to the switch. If the new switch that will be installed in the thermostat housing would turn on the fan at 215 and off at 195, and the manufacture calls for a thermostat of 195 degrees. Would the auxiliary fan run all the time once the coolant has warmed up to the 195 degree operating temperature? I believe the thermostat that was originally at the end of the radiator cooling where the coolant is suppose to be the coldest had a 195 degree switch. Should I change the thermostat in the housing to a lower temperature one? :dunno: Just trying to think ahead, before problems araise, or am I thinking too much? :doh: PS what do you consider to be a late model thermostat neck?

thank for the info. I will try it in the thermostat housing and let you know how it works. Everything sound right :cheers:

what size tires can I turn on a Dana 30? What would it take to make it stronger? What would you recommend for now, until I have the funds to do the Dana 44 and 60, what about how wide these axle are in comparison to the stock Dana 30, 35 What about axle over spring to raise it up? What kind of tires do you recommend for all around use meaning off and on road, on stock rims? The Vehicle Production Broadcast form states P225/75/ R15 OWL whatever that means - sound like a bird that flies at night to me? How do you translate the vin number? 1J7FJ36L1KL545620? would you understand this? or where is the best place to locate the Chrysler language They say the Paint is APA PQ9 QQ9 whatever that is? :ack:

Who makes a fixed coolant temperature sensor that will fit a 1993 XJ Thermostat housing. I have converted my 1989 MJ 4.0 I-6 closed cooling system to an open one using the parts from the 1993 XJ from the radiator to the coolant reserve bottle and the thermostat housing. I just need a fixed thermal switch which is either on/off. The ECU recieves its information from the coolant temperture sensor on the drivers side of the engine block, so I only need and on/off switch that is thermostaticly controlled. :headpop: Does this sound right :nuts:

When I talk about changing the front axle, it is for strength purposes. Down the road I will change both the front Dana 30 and the rear Dana 35. I will also junk the Pewgoat BA10-5. I have a NP 231 transfercase. What would you change to turn this truck into a MUD HOG, ROCK climber? I live in South Florida where the weather is hot and the mud is DEEP. :chillin: Pete when jeep removed the CAD system in the mind 90's what did they use in its place? I bleieve in the KISS method, Keep it simple stupid. So I want to strip everything that is not needed. Throw the anchor overboard so to speak. The only power I want left is the radio AC. There are no power windows, seats, minors or anything like that I just want the truck to run and be street legal. I don't want to cut it up, but keep it as close to original as possible. But with the strength in the drive train to go just about anywhere. :thumbsup:

Nice job. Is there a reason why you used an adjustable thermostat?? It seems all I need is a fixed temperture thermostat switch (On/Off) to screw into the thermostat housing. In my old system it was in the radiator (Closed System). I am not worried about the ECU, that sensor is on the drivers side of the engine block. The new open system does not have a thread hole for the Radiator temperature switch AKA auxiliary fan thermal switch AKA electric cooling fan thernal switch. I just need something to turn the fan on and off when it is to hot. :hmm: I am a little behind, could someone explain Renix to me. How can I tell which system is in my 1989 MJ 4.0 MPI I-6? :dunno:

I pull my parts from a 1993 XJ :USAflag:

Pete you say that you went from a 3.08 to a 3.55. was this a total rear end change like from a Diana 35 to a 44? Or just the gears:???:

yep - In theory you disengage the front axle through the vacuum shift motor. Does this improve gas milage, since you would not be turning everything in the drive line? or is this just in theory? I guess it is an expensive way to turn on the dash light letting you know that it is four wheel drive. What has been your experience with this system Yes I agree If it only turns on the dash light, than JUNK it. What would you replace the front end with? I thinking along the lines of something with manual hubs? or I'am I thinking in a wrong direction? :dunno:

I read 1987comanche response to the brake problem, your right. My 1989 MJ with four wheel drive has different brakes, rotors and calipers, than his 1990 MJ. Under the supplier he used, I compared my 1989 MJ to and they were different. The wearever gold pads are numbered GMKD-203, rotors wearever YH141194, and the cardone brake rotors 184182. watch for the difference :nuts:

Seems like "Eagle" has the right information. I am working on my front disc brakes right now. I have an 1898 MJ four wheel drive. The rotors are eleven inches wide and the brake pads are 1 3/4 wide. What I am I getting into here? What are the best wearing brake pads, rotors and other parts to use? Are the front wheel bearing serviceable like in repacking them? or are they sealed? :dunno:

I need a Schematic or guidence to find where a lost vacuum line is suppose to be landed for the four wheel drive (transfercase) operation. After removing to coolant pressure bottle from the old cooling system along with cleaning up the wiring and vacuum lines. I have a lost end, it is the blue vacuum line going to ???????????. The yellow, green and red have places to go, but not the blue. :help: 1989 MJ long bed with 4.0 MPI I-6

Eagle says that the ECU runs off the coolant temperature sensor on the engine block. So if that is true than the auxiliary fan thermal switch which is located in the radiator is for the auxiliary fan only. Since I have changed my old closed system to an open one, The new radiator does not have an threaded opening for the Auxiliary fan switch and I have to use the thermostat housing for a location for the Auxiliary fan switch. Do they make an on/off thermostaticly controlled switch for this purpose that will fit into the thermostat housing? this is a 1989 MJ 4.0 I-6 MPI. :dunno: Thanks for all the information :chillin:

Upgrade - what do others think of the old closed type system with the coolant pressure bottle with the plastic screw on top? Has anyone else had a bad experience with this system. What do you think? :popcorn:

Thanks for the input, is there an on/off switch available for the thermostat housing? I like the part about moving the auxiliary fan switch on/off switch from the end of the flow of water on the down side of the radiator cooling, back to the hotter part at the thermostat housing. This would allow the auxiliary fan to come on sooner than later in theory. does it matter what temperature thermostat is installed? what sould it be? is there a down side to a cooler one verses a hot one? I sorry for stepping in on someone else thread, but I figured it may help this person also

all that comes out is cable :thumbsup:

I found a height sensing proportioning valve 52002369 from http://www.trademotion.com in Columbus, OH 1-614-238-1631. Probably the last one in the world. Trademotion also call themselves buyerschryslerjeep.com I think. It came in the mail yesterday - I can't believe it. Now I have to change my brake lines back to the orginal position. I also ordered the proportioning valve 52002497 by the master cyclinder. Does anyone know anything that could be a problem with this brake system?, or something that I should be actively looking at while I'am working on the system? What about the front disc brakes? This truck has only been running on the front brakes for a long time, the front rotors are the worst i've seen in a long time, because there has been no fluid to the back brakes because of the defective height sensing proportioning valve. any ideas :dunno:

What about my problem with my 1989 4.0 I-6 and the auxiliary fan thermal switch that is located in the side of the radiator on the old closed system. The newer 1993 XJ open system that I replace the old system with does not have a threaded hole in the radiator for this switch. Someone said that the old switch was an on/off switch whereas the new one in thermostat housing is a information switch. :dunno: are they both run by the ECU? :hmm:

Thank you for all the great information, I truely consider this a joint effort. Anyway; back to the project. I was at the pull yard looking for other parts when I spotted a copper radiator in a 1993 XJ. This is an open cooling system, I have had nothing but boil-over problems with the factory installed close system. I even tried buying new factory plastic screw tops. This did not change a thing. So it is time to junk the old closed cooling system. After removing the radiator and the coolant reserve bottle from the 1993 XJ, I firgured that was everthing I needed to complete this job. Not so from what I have read from the above input. I forgot about the electric cooling fan thermal switch that was mounted in the old system radiator. The copper one I pulled did not have a threaded hole in the radiator for this switch. I found out when I was installing it in my truck. What do I do? from what I read in the information that you all have provided above, it is in the thermostat housing, but - this is not just an on / off switch? :help: Next item - I had to move things around so the new coolant reserve bottle would fit. The first thing in the way was the high voltage ignition coil. It was mounted at the bottom of the fender well, or the top of the coil spring mount, in a 90 degree bend piece of metal to keep the coil from bottoming out on the fender well. the coil is somewhat round, so it has to be elevated about an inch for proper fit. I straighten this piece of metal out flat, so the coil went from laying down, to standing up close to the distributor, and just behind the AC compressor. Is this a probllem? This gave me the depth I needed for the new coolant reserve bottle. The bottle also had two upper supports, I had to cut this support in half to make it work at the new location. I dry fitted it first, to obtain correct marks for drilling the holes. Next was to remove the wheelhouses or inner fender, which I encountered rusty fender bolts and the brittle plastic inner fenders. There must be something better to replace it with. Next was Drilling the holes for the bottle supports and bolted them down to the fender. Next was the four relays on a rack along with two test ports, which I moved closer to the right fender, and screwed all these items above down with 1/4 - 20 bolts through the fender well. Next was the starter relay, mounted it on one of the upper support arms to the coolant bottle, its real close to the battery, but you still can service the starter relay and the fusible links without unscrewing anything. Turn out to be a real nice fit. thanks again for the information PS I have just two problems one was when I was cleaning up the electrical wires, and vacuum hoses along with strapping everything down tight - I ended up with a blue vaccum line from the transfercase with no where to go. This is in the bundled of lines colored yellow, green, red and blue. any ideas :dunno: The other problem is with the auxiliary fan thermal switch and the thermostat housing mounted one, with it being an on / off switch verses a information sending unit; any ideas? :headpop: This is the third time I have tried to write this information down, because I keep loosing it, from not understanding this system yet Be patient with me - I am slow

how many miles on the engine? I used an aftermarket RMS with no problems. Make sure to lubricate the seal before installing it. oil the inside of the seal, and dishsoap on the outside to help it slide around the crankshaft. If it is going to sit for a while then use grease instead of oil. Make sure to add a little RTV Sealant to the corners, where the rear and front main caps meet the engine block to insure a good seal :D I also agree with a one piece FEL-PRO oil pan gasket. The one I used was OS 34308 R for a 4.0 I-6 Use a torque wrench to avoid errors. There are two different size bolts in the oil pan. The 1/4 X 20 torque to 84 inch pounds and the 5/16 X 18 132 inch pounds. I also replace the oil pump which I read on one of the blogs, for high mileage engines. They recommended a Melling Mel-M167HVS pump made in AMERICA which I installed. My Harmonic balancer rubber clutch was separating so I replace it along with the water pump and timing chain which was loose. Have fun :chillin:

I want to thank everyone on this site for being open and friendly to us that are just get started down this road to adventure land with our toys. I have scraped my old closed cooling system in my 1989 MJ long bed 4X4 with a 4.0 HO, with 162,000 miles. I was at the u-pull yard yesterday looking for other parts when I found a copper radiator in a 1993 XJ with a 4.0 that was an open system. So I pulled it out along with the overflow bottle, and installed it along with a new fan shroud. I Had to relocate the high voltage ignition coil to make room for the long coolant overflow bottle. There just two problems; the radiator that I installed does not have an opening for the radiator temperature switch, What do I do :hmm: The other problem is in relocating the high voltage ignition coil, what choices do I have as far as distance from the distributor; how close or how far? Does it matter which position it is installed verticality verses horizontal or does any of this matter? :nuts: What should I be concerned with? again I just want to thank everyone for the friendship as well as the information, maybe one day when my MJ is where I want it to be, or some where close, I will bring it out for the ride. Just getting started on this project. :bowdown:

As new member to this club. I want to thank whoever put this website together. It has been informative for me. I find that my 1989 MJ long bed with a 4.0 HO and 162K miles runs great on regular 20w50 Castrol oil. That's the only oil I have ever known for the past 25 years. I buy it by the case. I ran it in my Suzuki GS750 2 wheeler which was a FAST crotch rocket, I ran it my E-350 Ford, and I ran it in a Toyota Corolla. It seem to work fine "IF" you live in warmer weather like where I live in South Florida. The Chrysler Motors book 81-326-9052 that came with my Jeep MJ says to use engine oil of API Quality SG or SG/CD SAE 10w30 Preferred. If you look inside the book on page 69 it tells you 20w40 or 50 which are good down to 30 degrees, 10w30 or 40 are OK down to 0 degrees, and if you are going below that use 5w30, it is good up to 60 degrees on the high side. But I know very little about the preformance of these oil grades or the manufactures. Maybe this will help :hmm:

The ECU is located underneath the instrument panel between the steering column and heater A/C housing. The ECU is mounted to a bracket by three screws :thumbsup:

The reason I know that the height sensing proportioning valve (HSPV) is clogged - is because I had a helpper pump and hold the brake paddle while I opened the brake line on the feed side of the HSPV. The brake fluid sprayed, so I tighten the line and had the helpper pump and hold the brake paddle again as I opened the other side of the valve. There was NO brake fluid flow not even a drop as I moved the HSPV arm up and down. So it is clogged. What do you think about removing the metering device within the valve, which would gut it out and turn the valve into a coupling. This would allow the fluid to flow without restriction. Would there be any trouble with the combination valve by the master cylinder in regard to return line pressure or flow? :dunno:

I just had the same situation, two different tranfercases, one being 231J, and the other being 231AMC that I bought from a junk yard to build up. From what I have read; they were suppose to be the exact same. It does not seem so. I found out the HARD way after I installed it in my truck, only to find out that it would not disengauge from full time drive. It also kept the front axle locked, as I found this out on the test drive. :fs1: There was vacuum at the transfer case switch. The 231 AMC appears to be a full time four wheel drive and the other 231J part time. I pulled the 231 AMC back out of my truck, and brought both of them together on the work bench for a side by side comparison test. I Postion each shift lever in the same shift postion on each transfercase, and hand spun both the tail shaft and the front output shaft to find a common reference point for each. I found out that the AMC tail shaft and front shaft made no difference in proformance charateristics through the four postion of the shift lever, in others words it never came out of four wheel drive. They both easily shifted in all four postion. The 231J is the original equipment from my truck. So I reinstall this transfercase and it works fine. :smart: I don't know if the 231 AMC has been altered, :dunno: I bought it out of a junk yard as is.