Car repair – Page 51 – The Jeep Guru

January 15, 2011January 15, 2011

Cat back Exhaust for Jeep Cherokee XJ

Cat Back Exhaust for Jeep Cherokee XJ

My old exhaust was crumbling apart. The tip had fallen off behind the holder and the muffler had a huge crack in the bottom. It rattled and rumbled.

I ordered the Dynomax system from Summit Racing through their Ebay store. It arrived in just a couple of days after I ordered. I had to laugh at the UPS man struggling with the huge box coming in my office door.

I began by lifting my Jeep and using a reciprocating saw to cut the muffler loose from the catalytic converter. There were a lot of old welds here so it was pretty messy. I cut the muffler to get room to work to clean it up.

The clamp at the rear hanger broke when I tried to unbolt it. I just twisted it out of the way. With both ends loose I was able to remove the muffler and tail pie as a unit from over the axle.

I used a variety of metal working tools to clean up the end of the cat. I cut off the bulk of the old pipes and weld beads with a torch. Then I used a 7 inch grinder to clean up the slag. I finished with my 4 ½ inch grinder fitted with a flap disk.

When I finished the reducer include in the kit slipped smoothly and snugly into place on the cat. There was a small hole in the pipe coming out of the cat so I elected to weld this joint closed rather than use the included clamp.

Next I slipped the muffler into place. I supported it on a stand while I fit up the tail pipe. It took some wiggling to get the tip to line up where I wanted it between the spring and the trailer hitch. When I finally got it in place I used a ratchet strap to hold it in position while I put a tack weld between the muffler and the tail pipe.

To get the rubber donut to connect properly with the hanger welded to the tail pipe, I removed the two bots that hold the hanger to the body. Then I slipped the donut over the hanger on the pipe and then I reattached the hanger using the bolts. This seemed easier than wrestling with the heavy rubber, which was cold and inflexible.

I then tightened the clamp on the rear hanger making sure the pipe was still positioned where I wanted it. I then installed the clamps at each end of the muffler. I rotated them so that the base of the clamp would face to the side. This gives maximum ground clearance and protects the ends of the bolts from damage.

Muffler clamped in palce - Jeep Cherokee

With all the clamps in place, I removed the support and gave it a good shake to make sure it was positioned where I wanted it. I then lowed the Jeep and started the engine. I raised it back up and checked for leaks. Finding none, I was ready for a test drive.

Cat back system complete - Jeep Cherokee

The Dynomax system has a nice throaty rumble without being loud. I am very happy to have my exhaust gasses exiting from behind the Jeep again instead of from underneath.

[phpbay]jeep cherokee exhaust, 10[/phpbay]

January 13, 2011January 28, 2011

Rear Wheel Bearing Replacement

Rear Wheel Bearing Replacement – Jeep Cherokee Dana 35

Janice’s 1999 Jeep Cherokee has had a roar in the rear axel for a while now. I finally got around to checking on last week.

I ordered new bearings and seals from Crown Automotive. Since her rear differential is the Jeep Trac Loc, I had to have the friction modifier compound for the grease. I found that at Advance Auto.

I began by lifting the Jeep and removing the rear wheels and brake drums. These had never been off and still had the little clips from the assembly line on two of the lugs. I cut those off with dikes.

Next I let Janice remove the cover. Janice dropped it in the bucket of grease that made quite a mess.

Next I used a 1/4 inch 12 point box end wrench to remove the bolt from the cross pin. I had been concerned that pulling the axles on a Trac Loc diff would be more difficult but it was exactly the same as any other stock Jeep Carrier. I just removed the pin and slipped in the axle to release the C clip.

I removed the left side axle first as it seemed the noisiest. I had a little trouble getting the seal out because the brake shoes were in the way of getting a chisel in like I wanted to. But using a combination of the chisel, vise grips and a seal puller, I eventually popped it out.

I then used an axle bearing puller attachment on my slide hammer to pull the bearing. It takes quite an impact on the slide hammer to get the bearing to move. I have done this job on other Jeeps so I knew to hit it hard. The bearing came out smoothly once it stated to move.

The new bearing seems a very tight fit. I had trouble getting it to start straight in the axle tube. I did not have a bearing driver quite the right size and in trying different ones I somehow damaged the bearing. I noticed some of the rollers missing when I got it in place. So I had to use the slide hammer and pull the new damaged bearing.

I was more careful with the second bearing and got it in with no problem. I put a small amount of Permatex on the outside of the seal and drove it in place. I put a little gear oil on the seal to prelube it.

As I was wiping down the axle shaft to reinstall it, I noticed that there was checking in the bearing race on the shaft. Shaft will have to be replaced. I checked for spares but the only one I had was from a ZJ and the ABS tone ring was different. I replaced the original shaft temporarily.

I slipped it in place and reattached the C clip. I pulled the other shaft and noticed it had some wear as well. I will have to get two replacement shafts along with another bearing to complete the job. I reinstalled the other axle and C clip and coated the cover flange with Black RTV.

After letting the RTV set up for a minute or two, I reinstalled the cover and tightened the bolts in a crisscross manner. Janice refilled the diff with gear oil and the tube of friction modifier.

I later pulled the ZJ axles and looked at how to remove the tone rings. My bearing puller was not long enough to reach. I knew I could use my Dad’s press but I did not want to make the drive to his house.

I did some research on the internet and found a forum post that suggested that the rings would come off easily if heated. Since it was very cold out, I decided it would be a good time to try. The forum post had indicated that the tone ring was aluminum so I was being very careful not to crack it.

I put the axle shaft in the vise and began heating the ring with my acetylene torch. Soon I was able to pry the ring of the seat. I dropped it on the floor to cool. I noticed that it did not sound like aluminum.

I took a magnet to it and found it was indeed magnetic. That made sense to me since the tone ring is used to generate a magnetic field for the sensor to rear the wheel speed. It had to be steel. I was more aggressive with the heat on the second one and it slid off easily without any prying.

These shafts had no visible wear on the bearing races and look like they will make fine replacements. I just have to get more gear oil and another bearing and then find time to do the job again.

UPDATE: I have the spare axle shafts ready to go in but so far the old axles are running quietly. I will just let them run for a while.

[phpbay]dana 35 axle, 10[/phpbay]

December 31, 2010December 31, 2010

ZJ Dana 35 rear

Today I sold the rear axle form the ZJ parts car I have had for a while . I bought this burned out ZJ just to get the rear brakes to put on Scuffy.

Many parts have already been scavenged off it and there is not much left. I have been planning to haul the rest to the scrap yard and with steel prices up now may be the time to take it.

However, last week I got a call from someone needing a rear axle. I asked for their axle in return so that I would have a way to load it on the trailer when I haul it off.

As I was getting ready to load their old axle, I wiped off the tag and noticed that the ratio was different form the one I had just delivered.

I left it with them any way. I showed them places to buy the right gears.

I also had to help them pull the backing plates off the axle for the brakes. They seemed surprised that someone had pulled the axles out just to remove the backing plates. They did not seem familiar with how to pull the c clips so I helped them install the backing plates on the axle I sold them.

To pull the axles, you have to remove the center pin form the diff. On the ZJ Dana 35 this involves removing a 6mm 12 point screw. He did not have the right tool so we hammered on a cheap 6mm six point that got enough bit to pull the screw. With the screw out, simply slide the pin out. Be careful not to spin the carrier as the spider gears will fall out of place.

With the center pin out, the axle shaft can be slid in enough to drop off the C clip. The the axle simply slides out. To reinstall the axle, you have to lift up a bit on the shaft to get it to pass through the bearing. Then slide it in and slip on the clip. Then pull back to seat the clip in the spider gear. Reinstall the pin and the screw to put it all back together.

December 16, 2010December 16, 2010

Tire Rack Review

I buy almost all my tires online. The latest exception being my Maxxis Buckshots that I bought through a local wholesaler. I have my own tire mounting machine and a balancer so I just order them and install them myself.

Tire Rack has given me by far the best service. They have always delivered the tires on time and in good condition. They usually arrive via UPS and my driver knows to stack them by the door of the shop. He still gets confused when I get five tires instead of four.

The latest set of tires delivered to me from Tire Rack was Jenny’s Dick Cepek Crushers. She is an internet bargain hunter but also shops by reputation. She was able to get the Dick Cepeks for just a few dollars more than bargain tires and they were delivered in time for a very important off roading trip.

I have also purchased tire and wheel combos from Tire Rack. I bought a set of OZ wheels and Yokohama tires for my Eagle Talon. They arrived nicely packaged to protect the wheels from scratches. The lugs and centering rings were included. Since I purchased the set, they mounted and balanced the tires for free.

I have bought several sets of Michelin tires from Tire Rack as well as the Yokohama Geolanders that I just put on my Suburban. They always have very competitive pricing and excellent shipping rates. In fact, when comparing prices, I noticed that some places quoted a lower price for the tires but the shipping and handling charges were outrageous.

I ma not sure how they do it but Tire Rack ships faster and cheaper than any other tire store I have tried. The only way to get tires faster would be to drive to the distributor and pick them up myself. And that is only if there is a local distributor.

I have become a big fan of Kumho tires ever since I got a set of their Rally Racing tires. I have run these on my Cherokees and my son has a set now on his Cherokee. Tire Rack has much lower prices on the Kumho tires than the local tire stores and they carry a larger selection of sizes.

If you are in the market for tires for your Off Road Jeep, your street SUV, your sports car or autocross car, I highly recommend Tire Rack. Please share your experience in dealing with Tire Rack in the comments.

December 15, 2010December 15, 2010

Transfer case replacement – Jeep Cherokee

Replacing a Jeep Cherokee Transfer case

Yesterday a friend called saying her transfer case was leaking. I was expecting a seal leak but it turned out that there was a hole in the case itself.

I had also planned to drive it to the shop but with the fluid rapidly exiting the case, I decided to trailer it. When I got there with the trailer, the ramps were frozen to the trailer bed. It took some banging to get them loose.

With her Jeep in the shop, I picked it up and inspected further. There was indeed a hole in the transfer case. It looked like it was punched from the inside. Although, it made no strange noises when I drove it on the trailer.

I began by draining the rest of the fluid. Then I supported the transmission. Next I removed the front and rear drive shafts. An 8MM hex wrench was all that was needed.

I then unbolted the transmission mount using a 13MM socket. Then I dropped the cross member by removing the 15MM bolts and nuts that hold it up. That gave me access to the transmission mount that is held to the transmission by two 18MM bolts. These bolts have thread locking compound on them and are hard to turn all the way out. I inspected the mount which is often broken in high mileage vehicles like this one but it was fine. Next I slipped the exhaust mount off the tab.

Rather than mess with the shift linkage bushing in the cold, I unbolted the shift lever from the transfer case. I selected 2wd and used a 9/16 wrench to remove the nut and washer. I carefully lowered the linkage out of the way.

Next I removed the speedometer drive by unbolting the 13MM retaining bolt and removing the clip. I left the sender attached to the wiring harness. I pulled the harness away from the mounting tab on top of the case. I unplugged the mode light switch and moved the wiring out of the way.

Next I unbolted the six 9/16 nuts that hold the case to the transmission. Five are accessed using a box end wrench. The last one is behind the transfers case shift linkage bracket and has to be accessed using a 9/16 socket and a long extension. The two near the exhaust pipe take some patience to get off unless you remove the exhaust pipe. Since this one was in good shape and welded in place, I left it alone. Lowering the case down helps get access to these two nuts.

With the six nuts off, the transfer case slides easily off the transmission. I then prepared the replacement case to go back in by putting it in 4wd. This allowed me to rotate the front yoke and make the input splines turn to line them up. With the replacement case in place I started a nut to hold in there.

Next I tightened all six nuts. I then reinstalled the shift linkage, wiring harness and speedometer drive. I then reinstalled the front drive shaft as it is easier to access with the cross member out of the way. I filled the transfer case with fluid before putting up the rear drive shaft as it is easier to get the bottle in place with out the drive shaft in the way. The 231 holds a little more than a quart of ATF.

I then put up the exhaust bracket and transmission mount. Again, these bolts are hard to turn due to the thread locking compound on them. I then put up the cross member and bolted it to the body before lowering the weight of the transmission onto the cross member. I then reinstalled the four nuts that hold the transmission mount to the cross member.

Then, I reinstalled the rear drive shaft. I checked for leaks and loose bolts and then lowered the Jeep for a test drive. The replacement transfer case worked fine and shifted to all gears with out adjusting the linkage.

I plan to pull the broken transfer case apart to see what caused the hole. I will post an update when I do that.
[phpbay]jeep transfer case, 10[/phpbay]