Duner

It might be an o2 sensor does the engine run better win get the revs over 3000-3500 if so you might change the o2 sensor to gain back the low end performance from idle to 3000.

Here we are back at the track bar debate again. Most of the bars on the market are junk. They almost all require some re-engineering to fit and function properly depending on your lift. I have never used the rusty's or the jks but after all that I have read and that I have looked at in this forum and others my money is going for the jks when I replace the my skycracker bar. I would sell my bar now but I have found it necessary to cut reshape relocate and weld the bracket to my front axle. I could have made brackets and retained the stock bar if I had known that the aftermarket bars were like this. Oh it works properly now with the correct geomtry but out of the box it sucks. It interfered with their steering stablizer.

I'm already running a mix of royal purple and regular lube 75/90w in the tranny now. I pretty sure it's a synchro problem but as the shop said you got to remove the shifter anyway so check out the bushings first. If I pull it. They said the bench labor would run $225 parts would run between 150 to 200 if nothing is hurt. 450 to 490 with the tax. 12mo/12000mile warranty. Or I can get an exchange tranny from them for 1,200.00 - ouch. I'll check out the bushings, my dad has been doing business with this shop for about 27 years.

I having problems shifting my ax-15 especially down shifting from 3rd to 2nd gear. My dad's friend at the transmission shop said to check the shifter bushing and shift rod bushing before pulling the tranny for a rebuild. Has anyone ever done this?

Ok, pump was dead, replaced with autozone special, I think it's designed for the xj and not the mj required some fitting to make it work. Anyway truck started and now runs at 3000 rpm. (isn't life great) disconnect IAC, TPS and MAP no luck. disconnect everything again and pull throttle body and give a light clean up re-connect and idles at 750 rpm. The Renix is fantastic but I don't think we will ever no why unplugging sensors would fix this or why it periodically does it to begin with. Anyway one fuel pump/sending unit/filter and can of carb cleaner later and she's back on the road again.

OK, my apologies as I'm sure this has been covered before, but I do not have the time to search and review all of the threads. Intermittent response from fuel pump. The truck died on the highway (while my dad borrowed it, so I can't be blamed) no audible response from the pump. Triple A towed it home and still no response, then like majic pump kicks on and truck starts. It ran for a couple of minutes then my dad goosed it and when it dropped back to idle it died and again no fuel pump response when the key is turned. Haynes fails to identify the fuel pump relay and says the dealer should check the operation for you. Anyway swapping the relays has brought no improvement. The fuel pump still fails to come on. What voltage should be present in the fuel pump/sending unit connector when the vehicle is in the start mode? I'm reading 7.5 but I'm going to try grounding in a different location. I thought that the pump is to receive 12volts at start then drop off to 8 or 9 volts while running and yes the resistor is good (measured 3.75 volt drop across terminals) and bypassing the resistor still produced no response in the pump. So before I lay down money on a new pump is there anything else I should check for and does someone actually know which relay goes to the fuel pump on a 1990 4.0?

I'm all for safety but do really want DRL's, my sister's 99 camaro and my mom's 05 malibu both use the front turn signal ligts as DRL's. The result is the camaro is frying and melting the light sockets and wiring because of heat build up and the malibu is starting to discolor, fog and crack the headlight lense right next to the turnsignal bulb. This is a great safety tool but it is damaging both of these cars and costing money to maintain the system. I think you should just buy a set driving lights and use them when you drive during the day if it is legal where you live. this way if they burn up your only out a few bucks and you don't have to mess with the jeeps wiring.

I hate the e-brake on the comanche it always breaks just before the safety inspection is due. Has anyone successfully converted to a XJ setup yet? It would be better for offroading anyway if I could apply the brake with my hand while I'm feathering the clutch and gas.

My dad and I spoke directly with the advance adapter's people when they were in town. If you are planning on swapping a SBC 350 or larger then you better plan on swapping the tranny as well. The torque of a mildly built 350 will definitely destroy the AX-15 in a short time. We discussed using a stock 305 sbc, their opinion was that the ax-15 could hang if you did not abuse it. All in all I have to thank them for their up front honesty most companies just want to sell you some parts but instead they basically interviewed us about driving style and use and deemed we would be better off waiting until we were ready to commit to an entire driveline change.

I think its time to look at your 4.0 and not your gears, does your engine feel lifeless below 2500-3000 rpm? If so you may want to change oxygen sensors, I did numerous things to my truck over the last two years but without a doubt the new o2 sensor did more for performance and mileage than anything else I have tried. (performance great, mileage is up +10% overall in fact highway mileage is about 18.5 again) The truck pulls harder now with the 33's, 3.55 gears, 4.0, ax-15 and 4wd than it ever did as 2wd with the 215 70 tires. I don't like to abuse the drivetrain but it can break the right rear tire loose if I want it too and my buddy with the 94 chev 5.7 litre 2wd is pissed because I can keep up with him dead even now. So I can't wait till I swap to 4.10's.

I thinnk the double cardon shaft first appeared when jeep placed the 4.0 in the comacnhe and cherokee although I remember seeing the cv joint on the later 2.5 vehicles when I was shopping for the front shaft at the salvage yard. I'm sure somebody has the data on the models and year changes. Just look at all the 4.0's until you find the right one.

Ok, the notched factory spring plate/shock mount could not take the abuse of normal driving and light offroading so my dad has designed some plates that he feels are more up to the job at hand. The new plates are over kill but we like it that way. They were made from a 5"x5"x1/2" square steel column. If you are interested in having a pair send me an email (email posted under user info) we need about two dozen to make it worth while with the cost of steel and the quantity that you have to buy. We bought a small quantity for this job and were into it for about $70.00, My dad thinks that if there is enough interest we can get the price down to $35.00 + shipping for the pair. Old Plate failed (my apologies to Eagle for cutting them up but they were weak) http:// 1/2" solid steel - the toolman would be proud 5/8" Grade 8 bolt for the shock mount - should be stronger than stock Installed on the truck! no worries now http://[/size]

The first swap took a number of weekends but I wasn't on a time schedule. The 2wd ax-15 locked up I spent a week trying to find a replacement all of the trans available were for the 2.5 not the 4.0. Finally found a 4wd ax-15 for 4.0 at a total cost of $275 for the trans and transfer and so that's how the 4wd conversion started. Tranny swap completed in about 5 hours, driveshaft shortened on monday about 1 hour. Front axle swap - half day to pull it - 2 todays to clean and paint - half day to swap it fortunately I had new brake calipers for my 90 and I used a d30 froma an 89, same brakes so no issues there. 4wd shifter removed xj at a later time and last was a drive shaft from an xj. Now that I no what to look for and have experience a weekend is more than adequate if you have your parts together dirveshafts altered on the first day of the week and your ready to go. Of course this does not include complicating things by lifting at the same time like I did.

I have not had any problems since I got rid of the precision u-joints that O'reilly and Autozone sell. I using mostly spicer greasable joints and one brute force sealed.

The mig has killed brazing for the most part but there are still some areas that are brazed - if you have brass radiator the tanks and hose connections are brazed and some body men still use it to fill small pin holes where the mig might distort the metal to much. All in all the gas torch is relagated to its best function now - cutting and heating if you heat cast iron hot enough you can actually use the mig or arc welder to fix the cracks with steel instead of filling with brass.

When you extract your xj replacement from the salvage yard make sure the vehicle doesn't have the same problems (find an automatic trans car) and check for water damage as the windshields leak on top of the fuse box as well. When you remove the good box cut the harness about 5 or 6 inches below the box just in case you need to do some wire splicing. My mj had some local service station mechanic repairs by the PO and that caused more issues it took a solid day to fix it but it was worth it. In fact you can often by xj's cheap because half the electrical doesn't work and the owners have no idea or they were told that it would cost $700 plus to repair the vehicle so they get rid of them cheap.

probably not a bad choice for as wet as it has been in the houson area this summer but let me get this straight. We use airplane tires on the tractors to keep the thorns from flattening the tires. You want to use tractor tires on your trail rig, so I guess we can use the truck tires on the go cart. No seriously, I'll have my dad check the tire prices (TX farm bureau member) but I think that those tires cost more than dot legal super swampers.

The auto trans shafts are longer than the manuals (atleast on the 4.0's) but it is only and 1" or maybe 1.5" longer. but any good d-shaft shop can lengthen a shaft too.

I pulled a box from an xj and replaced everything including many of the metal connectors, then I made a rainshield out of aluminum in case the mc or brakes dump fluid on it again. I have not had any problems since then and my wiper squirters actually work sometimes.

I hope your ok on the 47" I had mine cut to 46.5 and it fits the d44 soa setup perfect but I do have the 4.0 and the ax15.

Yea, I hve a strap kit but was not sure the yoke could be drilled to a larger hole, 4 wheel parts sent the strap kit with the stock yoke my dad ordered for the 05 wrangler, so either we were supposed to drill it or use the stock straps and bolts - we used the stock.

Ok, your probally just about crazy at this point and even contemplating selling your MJ. All I can tell you is take one more thorough look around under truck from the fron to the back. Start at the harmonic balancer, check the tranny to engine block bolts, remove the inspection cover and check torque converter bolts, flex plate and bolt mounts, check tailshaft of trans, new driveshaft did they handle the slip yoke or did you remove it before they worked on it? if they did it move on to the rear yoke on your diff - its possible that its cracked or it has been slightly bent. The vibration as you described it is typical for the driveline. If you had a 4wd you would need to check out the t-case but since its 2wd I would concentrate on the flexplate converter area of your aw4. Again given that the vibration is consistent between 35 to 45 and worse during acceleration than deceleration. That stroker engine may have cracked your flexplate.

My dad jumped in the truck to run to the hardware store yesterday and comes back declaring that he felt a funny vibration in the driveline. Road test confirms the vibration. Wait two hours for the truck to cool down and start checking all of the bolts under the truck - we now do this as part of the monthly under vehicle fluid checks anyway. Found all u-joints in good shape, greased all joints and front shaft. The culprit for I think the third time now was the rear diff u-joint strap bolts backing out. This time the bolts which are relatively new were removed and re-installed with thread locker. This yoke is due to be upgraded as part of the diff rebuilds and new gears coming soon but is anybody else having similar problems with this or should I have been using thread locker from the begining. I guess the u-joints were failing prior to the strap bolts loosening and we hadn't noticed the problem. Finally who makes a good yoke that doesn't cost an arm and a leg?

The drop pitman made the biggest difference in my truck of just about anything done. You have to get the track bar as close to parallel with the steering linkage (knowledge I could of used before I started lifting the MJ) to help eliminate the bump steer. As for everyones personal experience with this it will depend upon the different componets they chose to use. Every mfg has different mounting ideas especially when it comes to track bars. If you got one that mounts closer to parallel with the linkage you may not need the drop pitman. My skyjacker track bar definitely needs the pitman dropped. Eagle it may be about time to have everyone gather up all of there lifting knowledge and make a "sticky" for the sight. We have all been down the budget road and many of us are now in the high dollar areas and we have learned a lot along the way. I'm now the jeep lifting expert at my school. I know everyone's opinion is different about the mfg's products but I think that there is still some basic knowledge that is true of all the Comanche/Cherokee lifting geometry that we could compile into a sticky for all of the newbies and help remind all of us oldies of all the things we forgot along the way.

Eagle is correct about the early 4.0 comanche's computer does not remember anything once the key is cut off. The factory also issued a harness upgrade due to signal degradation in the CPS circuit. This is the only upgrade that I have not done but I will be doing it soon, as my truck failed to start the other day even after recent replacement of the CPS a couple of months back. The following is a reference and part number to Chrysler's fix for the problem. Although I beleive even with this modification the 87 to 90 4.0's will still crank longer than the newer models. If you go this route I think the dealer charges about $100 bucks but it includes the new sensor as well. I'm going to try it without the sensor since I just replace it in May. Subject: Crankshaft position (CKP) sensor and harness replacement on 1987–90 Jeep vehicles with the 4.0L engine Symptom: No start, cranks okay Source: Chrysler service bulletin 18-51-88 The symptoms described above could be caused by a weak signal from the CKP sensor. A new CKP sensor and harness is available to correct this problem. The new CKP sensor is available in a kit, part number 83100066. The kit includes the new CKP sensor, and a sensor patch harness for connecting the new sensor directly to the engine control module (ECM).