Jeep – Page 7 – The Jeep Guru

May 30, 2010May 30, 2010

The Red Jeep Chronicles – Flat tire in the rain

Today, Will and I were repairing a broken radiator hose on his Jeep Cherokee. We decided to take the red Jeep to town for the parts run.

Less than a mile from the house, I heard a whirring noise form the left front tire. I also felt a sudden pull to the left. I looked out the window and the left front tire was completely flat!

I stopped in the road and backed in to a convenient field entrance since this road has no shoulder. I flipped up the seat and discovered that the jack I expected to find there was missing!. I had a spare but no jack.

Just as Will and I decided to just walk to the house, it started to rain. And rain very hard. We were just beginning a conversation with the folks sitting on their porch at the next house up the road when we had to dive for cover in the Jeep.

After the rain calmed down a bit, we decided to ask the folks there for a ride to the house. The fellow was nice and drove us the mile or so down the road.

At the house, I picked up the floor jack and the trailer spare. I also got a long breaker bar and a set of deep well sockets.

Back at the Red Jeep, I noticed that the tire was not just flat but the tread had separated and the sidewalls had split. I am glad I was doing only 30 mph or so when I heard it. The rim was not damaged.

I was really glad I had brought the breaker bar and sockets as the lugs were very hard to get loose. But after some struggling they all come loose and I was able to swap on the spare. About that time, the rain quit.

Will tossed the torn tire into the back of my Jeep and drove it home while I drove the Red Jeep. I guess Scott will be shopping for a set of tires before he can sell it now.

April 20, 2010May 13, 2010

The Red Jeep Saga

Jeep Wiring Diagram from XKCD

My son Scott found the Red Jeep on Craig’s List. His original intention was to buy it for parts as the engine bay wiring harness was melted and he bought it for near scrap value.

The owner gave us a very small time window to complete the deal and pick up the non running Jeep. We arrived in the dark and began pushing the Jeep into position to load it on the trailer. In the dark, Scott hooked the tow strap to the axle in a way that put pressure on the tie rod causing it to bend just as the front wheels got on the trailer bed.

I was using a come-a-long to winch the Jeep onto the trailer and it became very hard to pull after the tie rod bent. I did not have the correct tools to pull the tie rod so I attempted to use a ratchet strap to straighten it. About this time the owner showed up with the paper work and wanting his money. He seemed to think we were complete idiots for having so much trouble loading the Jeep. He also just walked away without a word when I asked to borrow a wrench from him.

By the time we had the Jeep loaded, there was quite a crowd gathered at the closed shop where the Jeep was stored. We were very glad to be loaded and out of there as we were getting a bad vibe about the whole situation. But we left with the Jeep and the title so we were good.

When we got the Jeep back to the shop and looked it over, we found it was in excellent condition except for faded paint and of course the missing engine bay wiring harness. Scott decided to try to make it run again instead of just parting it out as originally intended. I assured him it would never run again, but he was determined.

Scott and Megan began searching pull -a- part yards for a wiring harness. The 89 is a strange year for wiring harnesses. It appears that on some Jeeps, and this being one of them, that a wire was omitted from the computer harness and had to be added at a later step in the assembly. Since the computer is under the dash in 89 a hole had to be drilled to accommodate the extra wire. This hole was drilled rather crudely on this example.

Scott eventually found a harness that did not have the extra wire and got the whole harness and computer just in case. After several hours of sorting out the various plugs, he finally got it all connected. Much to my surprise the Jeep fired right up. However it did have a stumble or a miss.

We double checked the injector wiring and spark plugs but could not find the source of the miss. However everything else worked great.

A few weeks later, I removed the bent tie rod and straightened it using my pipe bender. It actually turned out to be pretty straight.

Scott got busy with other projects and let the Jeep sit over the winter. He eventually found a potential buyer for the Jeep as it sat.

He fired it up and started to drive it back to his home but he did not make it very far. Over the winter, we both forgot that the front end alignment needed to be set after repairing the tie rod and the Jeep was just not running right with the miss.

I took it back to the shop. A few days later, when I got ready to set the front end, it would not start. It seemed the NSS was stopping the starter from engaging. I had a spare transmission in the shop so I pulled the NSS and plugged it into the harness and it still would not start. I even put a jumper across the wires to the NSS and it still would not start.

A few days later, I studied the wiring diagrams and then tracked down the wires to the starter relay. I found that by jumping the wire that goes to the NSS to ground, the Jeep would start. I also found that there was no continuity in the wire from the relay to the NSS connector. So, for now, there is a jumper in place to start it.

Also, when I got started, the Tachometer and temperature gauge no longer worked. They had been working fine earlier.

After setting the toe, I took the Jeep for a test drive and it drove great. But it still had a miss. I drove to Dayton to meet a friend for lunch and when I got home, I parked it on the porch behind Janice’s Jeep to drive it the next day.

The next day, it would not start. I had to push it out of the way. I checked and rechecked the starter wiring. Eventually, I applied power to the starter motor with a jumper cable and still nothing. The starter motor had simply quit.

I pushed it to the shop and installed a spare starter. It fired right up. But it still had a miss. There was also a strange noise coming from the power steering pump so I got out my stethoscope to listen to it. By the time I had the stethoscope in hand, the pump had quieted down so I decided to listen to some other things.

I noticed I could hear the click of the injectors quite distinctly so I decided to listen to them all. When I reached number six, there was no click. Just the whine of fuel in the rail.

A few days later, I decided to check further. I pulled the wire off and measured the resistance on the injector. It read about 16 ohms – the same as the spare. I connected a voltmeter to the harness and there seemed to be pulsing voltage there. It was hard to tell with my digital voltmeter.

Next, I connected a spare injector to the harness and I could feel it clicking in my hand. So I decided to swap out the injector.

I pulled the fuel rail and then when I went to swap the injector, I had misplaced it. I looked for several minutes knowing it had to be nearby; but eventually, I went to the bin and got another spare. I popped it in place and re secured the rail. I started the Jeep and had to shut it down immediately as gas was spraying everywhere. The O ring on the spare injector was bad.

I pulled the O ring off the original injector then I put it all back together again. I started it up and this time there were no leaks. However, there was still a miss. I was stunned.

I made up a test light using a side marker bulb and socket from the parts ZJ. I plugged it into the harness and sure enough the light blinked when the injector should be firing. I got out the stethoscope again and listened. No clicking. About that time, I saw where I had put down the first spare injector. I plugged it into the harness and I could again feel it clicking in my hand.

So, once again, I pulled the fuel rail and swapped the injector and O ring. I let the rail pressurize and checked for leaks. Then I hit the starter and fired it up. It took a bit, but soon, the engine smoothed out to the nice purr that these inline sixes are famous for.

The tachometer and water temp gauge still don’t work but at least it runs and drives well. I am sure that there is simply a ground wire loose that will fix both the gauges. I just have to find it. Marcus Ohms suggested I look behind the cluster so I will have to pull the dash to check it out.

Update: I pulled the dash to look for a loose ground connector. I also printed of the wiring diagrams and started looking for things the non working items had in common.

First I tested the ground connections and found they all had continuity. I also checked the power feeds to the dash and they all had voltage at the proper times.

I noted that the Tach and temp gauge that did not work shared power with the fuel gauge that did work. So I ruled that out.

I began working on each individual gauge. I started with the purple wires of the temp sensor. The temp sensor has a test feature that grounds the sensor while the key is turned to “START.” This feature was working fine. I then checked from the connector in the engine compartment to the cluster connector and found there was not continuity.

I tried tracing the wire but it quickly disappeared into a harness on both ends. I considered running a new wire but I left that for a later possibility.

Next, I tested the tach circuit. I found that the green and white wire again did not have continuity from the coil to the dash. It did have continuity however from the coil to the test plug under the hood. Just not to the dash connector.

Finally, I moved on to the NSS connection. Since all three of these stopped working at the same time I was still looking for a common element. The black and white wire from the starter relay was easy to trace as it was partly out of its harness. I soon tracked it to a dead end plug. I quickly noticed that this pug also contained a green wire and a purple wire. I got very excited.

I looked around the engine compartment and found the other end of the connector. I plugged them together and I could not wait to give it a try. Trouble was, the dash was still all apart.

So, I at least wanted to see if it made any difference so I hit the key and the starter engaged! The NSS was working! I got even more excited.

This being a dash with a mechanical speedometer, it takes a bit more work to put it back in than the later electronic speedometer. I finally found that if I connected the short cable extension to the cluster I could feed it through and screw it to the speed sensor under the dash and connect it together there.

Once I got it all in place, I was very excited to see the Tach jump up when I started the engine. I had to wait a few minutes for it to warm up before I confirmed the temperature gauge was working as well.

I drove the Jeep to my office this morning and I love the way this Jeep drives. I may have to keep it.

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April 16, 2010April 16, 2010

XJ starter replacement

How to change the starter on a Jeep Cherokee

Remove the negative battery cable

Remove 8MM nut that holds the starter trigger wire to the solenoid.

Remove the lower mounting bolt. Note this is an SAE bolt with 9/16 head. It goes in from the front of the starter.

Remove the upper bolt. This one is metric with a 15 MM head that goes in from the transmission side.

Remove the starter and lower it enough to remove the battery cable from the terminal. This is a 13MM.

To install the new starter, first install the battery cable in place and move the trigger wire out of the way.

Position the starter so that it indexes into the hole in the backing plate. Start the upper bolt but do not tighten. This is the shorter metric one.

Start the lower bolt (longer SAE one) and make sure the starter is aligned properly with the hole in the backing plate. Tighten the bolts.

Attach the trigger wire and tighten the bolt.

Reattach the battery cable.

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April 11, 2010June 1, 2010

Lost and Stuck in woods

Lost and struck

Late one afternoon last week I decided to make a test run on Scuffy to see how the new tie rod worked. It was really dark when I headed into the woods behind the barn. I had not run this trail in a while and I don’t think I have ever run it at night.

This trail consists to two intersecting loops. I had started at the far loop and was looking for the intersection of the trails to head back up to the barn. Right before the intersection there is a gully that has to be crossed. Somehow; in the dark, I crossed the wrong gully just before the intersection. I thought it seemed a bit steeper but I was not sure until I ran out of trail just a few feet up the bank. I managed to get turned around, but in the dark, I was not sure where I was.

I decided to walk up the hill to get my bearings. As I walked up the hill in the dark, I saw a light and started walking toward it. As I got closer I realized from color of the light, this was the light from my neighbors house and not from my barn. Suddenly I heard my dog Smash barking as he had been waiting for me by the barn. I turned and walked toward the barking. Soon I made it to the driveway not at all where I expected to be. I thought I was behind the barn when I got lost but I came out in front of the barn.

I went in and got a flashlight. Then Smash and I went back to look for the Jeep. I had thought about leaving it in the woods for the night but since the trail I was one runs along the property line, I considered the possibility that I might have been on my neighbors property instead of mine. As I walked down the hill, Smash took off in a different direction. I shined my flashlight over where he was and saw the reflection of my Jeep glint through the trees.

Smash knew where the Jeep was before I did. Thanks to Smash I took a much shorter route back to the Jeep than I did coming to the house.

Once I looked around and had a good laugh about what I had done, I was able to easily get back to the trail and drive back up the hill to the barn. The new tie rod worked well too.

On Friday when Jennifer came to visit, Janice told me to show her where I got lost because she was still laughing at me for getting lost in my own woods. I made a quick run around the trail in Scuffy and let Jenny laugh at me for getting lost.

As Jenny was getting ready to leave, her son Caleb wanted to see the spot also. I had already put Scuffy away so I took him in Jenny’s Jeep Princess. Just like Scuffy her Jeep has a three-inch Rough country lift, a Lock Right Locker and Maxxis Bckshot tires. The big difference being that hers has 31” and Scuffy’s are 33”. That two inch difference turned out to be more critical than I imagined.

I stopped on the trail to show Caleb where I got lost. Then I proceeded to cross the gully just before the trail intersection. The gully has gotten a bit deeper due to the recent rains and was still a bit mushy on the bottom. Unlike Scuffy, Princess also still has her stock front bumper and air dam. I entered the gully gently so as not to stuff her bumper into the far side of the gully. My fatal mistake was not powering on from that point. I was a bit concerned about hitting her back bumper as the rear wheels dropped into the gully.

It turned out my concern was valid. As I dropped into the gully, the rear bumper hung on the bank and held both the back tires up out of the mud just enough to keep them from getting traction. Working the front back and forth just got me more stuck. Eventually, I gave up and Caleb and I walked back to the house. We had no trouble following the trail in the daylight.

Jenny and I went back in Scuffy to pull Princess out. I expected a quick tug on the strap would have her free. It took quite a bit of maneuvering in the tight confines of the trails. After scraping a couple of trees and popping off a piece of trim, I finally got the strap hooked up. Jenny fired up Princess and Scuffy tugged. Scuffy went sideways and Princess stayed stuck.

I backed up and gave it a bump, but Princess stayed stuck. I bumped harder and slid sideways into a tree. Princess stayed stuck and maybe dug in a little deeper.

Now that it was dark, we decided to try the winch. It took even more maneuvering and running over some small trees to get Scuffy into a position to use the winch and be able to brace on a tree.

The winch slowly extracted Princess from the gully and she started up the hill on her own. However, just a few feet up she stared to spin again and slipped sideways. I rerigged the winch cable and pulled again. The angle was not quite right so the cable bound up in the side of the spool. I had to stop to respool the cable.

By this time Janice had called to see what was taking so long. She suggested that we just leave the Jeeps and let Jenny and the boys stay the night. We tried one last pull and got Princess up to the point where the two trails intersect. She should have been able to drive out at that point but for some reason not visible to us in the dark, she just went sideways into the tree instead of out onto the trail. Scuffy was blocked in by the trees and could not move until Princess was out of the way.

We gathered up their luggage and hiked back to the house. Also in the dark since one of her boys had stolen the batteries out of her flashlight.

Where the two Jeeps slept after getting stuck

The next morning, Jenny was feeling ill, so while Janice took care of her, I went down to check on the Jeeps. I strapped Scuffy to a tree and cranked him up to respool the winch cable.

After surveying the situation I saw why Princess was stuck. Her rear tire was against a root and the root was pushing her against the tree instead of letting her go up the hill. It did not help that her Maxxis Buckshots were still at full pressure.

I simply backed up a couple of feet and gave it a bump over the root and drove up the hill. Hunter and I then walked back down and drove Scuffy out as well.

I built these trails as a training ground to develop my off roading skills in a relatively safe environment. They sure served their purpose this week as I got to practice winching, rigging and various driving techniques to recover Jenny’s Jeep.

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April 1, 2010April 18, 2019

Installing a Slip Yoke Eliminator SYE in a NP231

Slip Yoke Eliminator Installation — Well written instructions came with the kit

First I removed the transfer case from the transmission. This was pretty easy since they were both laying on my shop floor. I did have to jack up the transfer case to get to the bottom bolt. That seems a bit backwards as the top bolts are the hard one to get to with it installed in the Jeep.

Next I used my pressure washer to remove most of the dirt and grease form the outside of the case. There was all colors of mud. I am sure there was some from Harlan, Aetna Mountain and Golden Mountain as well as some other places still on there.

sye install NP231 — NP231 transfer case ready for SYE install

Next, per the directions, I placed the transfer case in 4 Low. Next I used a 1 1/8 socket on my air wrench to remove the nut on the front yoke and then removed the front yoke.

Next, using a 9/16 wrench I removed the selector lever. If I had not moved it to 4 low before removing, turning the nut would have shifted it there any way.

Next I removed the three 15 mm bolts that held the tail housing in place and tapped the tali housing off. This gave access to the snap ring that holds the main shaft to the rear bearing.

tail cone off — Removing the tail cone exposes the snap ring.

With that snap ring off, I removed the 10mm bolts that hold the output housing in place and tapped it off. The speedometer drive had been previously removed.

Output housing removed exposing the oil pump

Next I noted the locations of the three different types of fasteners that hold the two case halves together. All but one has a 15 mm head. Two of these have washers and go over the alignment dowels. For some strange reason there is one bolt that has a 10mm 12 pt head and is longer than the rest. It is on the top.

ready to seperate case halves — Note the location of the three different types of fasteners.

With all the bolts out, I used a flat blade screw driver to pry the case apart using the pry slots. I was careful not to pry anywhere else so I would not scratch the sealing surfaces.

At this point, some more fluid came out even though I had drained it earlier. I carefully separated the oil pump from the pick up tube and removed it.

After removing the rear case half, I inspected the chain and the magnet. Even though this Jeep shows over 220,000 miles on the odometer, the chain looked great and there was very little metal on the magnet.

Rear case off — View inside the NP231 with the rear case off

Next I pushed the front output shaft out and removed it with the chain. I inspected both the sprockets and the chain further. Still no visible wear.

Next I removed the main shaft from the case. I photographed the shaft so I would know the relationship of the mode selector and drive gear.

The snap ring was just a hair too big for my Craftsman snap ring pliers to open. So I modified the pliers by grinding off the stops just a bit so they would open wider. The snap ring then slid off easily. I was then able to slip off the mode hub and sprocket.

This being an early 231, I had to remove the caged bearing from the sprocket before I could reuse it on the new shaft. I used my ball joint press to press out the two bearings.

I pre lubed the new shaft and slid the sprocket in place and then the mode hub. I installed the new snap ring from the kit.

Next, I slipped the new main shaft into position in the case. I then removed the old spline seal form the front input shaft and installed it with the chain. I decided to wait until the front yoke is ready to go on to install the new spline seal.

I then test fit the rear case half to see if the shift rail needed to be modified. Sure enough this is one of the ones that required the rail to be cut as it extends 1/2 inch too far.

shift rail too long — Need to cut 1/2 inch off the shift rail.

I reinstalled the shift lever and moved the case through all its positions to see how the shift rail moved and saw that it only interfered in 4 low. I cut the extra shaft length with a cut off wheel on my grinder after marking the spot with tape.

I also inspected the oil pump and saw the pump housing seal was worn and needed to be replaced. I got a new one from Crown along with the proper RTV to seal the case.

After a final inspection, I applied a bead of RTV to the case and after letting it cure I put the two case halves together.

Here is where I hit my first snag of the installation. The oil pump needs to be installed at the same time as the rear case so that the pickup up tube can be inserted into the pump. On a stock transfer case, you can slip the pup off the drive gear and get enough wiggle room to install the tube after the case halves are together. However, on the SYE shaft, the rear section of the shaft is bigger and stronger making it very hard to get enough room to move the oil pump.

There was a bur on the output splines that the oil pump has to slide across and working by myself, I could not hold the case steady and guide the pump down the sticky splines. I went ahead and assembled the case halves, thinking I could install the dip tube later as I always have on stock cases.

I had already torqued the case bolts to 25 ft lbs before I realized I was not able to move the pump like I was accustomed to. However, with some fishing with a dental pick and a small screwdriver, I was able to install the pick up tube and eventually get it seated in the pump. Next time I will get help if necessary to make sure the oil pump and case go together as a unit.

Next I placed one of the snap rings for the speedometer drive gear on the shaft, then slipped on the blue drive gear followed by the other snap ring.

Next I applied a bead of RTV to the new output housing. The Crown Kit comes with eh bearing and seal preassembled in the new housing. I torqued the bolts to 17 ft lbs.

The output housing is drilled an tapped for a vacuum switch on the shift rail. However, the Jeep this case is going into does not use one and this kit comes with a handy plug. I noticed before screwing in the plug that the shit rail looked very close to the end of the hole. Sure enough on a test fit, the plug hit the end of the rail about one thread form being tight. I shifted the case around and found that if the plug was all the way in, the case would not fully shift into 4 Low.

I must not have cut the shaft short enough buy 1/16 inch of so. Rather than pull the output housing and cut the shaft again, I simply ground off the end of the plug. I had to remove about on thread to get it to clear.

Next I installed the two yokes and called it done for now.

I used a spare speedometer drive gear to plug the hole until the case is ready to be installed in Jenny’s Jeep.

The next step will be to determine the best way to set the pinion angle as the pinion now has to pint at the transfer case instead of being parallel to the out put shaft. Our plan is to use a stock front drive shaft in the rear position.

Overall, I was very pleased with the quality of the Crown Kit and the well written instructions. I am not sure how much time I spent on this project as the time was spread over several days. The new main shaft is much larger than the original in the tail shaft and speedometer drive areas so in addition to being shorter, it also looks much stronger.

Note how much bigger the SYE shaft is than the original

Update: The case is now installed in Jenny’s XJ. It took approximately 8 degrees of shims to align the pinion with her three inch lift. The shift rail needed to have been cut shorter as the plug will bind the shifting into 4 low if screwed all the way in. I added a second O ring to cure it. Other wise it works great. See the write up for installing the SYE in the Jeep Cherokee here.