Loose flex plate bolts

Stopping a common Rattle

One of the common problems with Jeep Cherokees withe AW4 automatic transmission is that the flex plate bolts back out after a while.

The flex plate is bolted to the torque converter with four relatively small bolts.  With age and time they get loose.

The noise is often diagnosed as a rod knock or something more severe and the Jeep gets sold cheap or scrapped.  If all the bolts fall out the Jeep will have no drive in all gears and be misdiagnosed as a transmission failure.

Inspecting the bolts is a relatively easy task.  They are hidden behind a small metal plate at the bottom of the transmission bellhousing.

This little plate is very well secured to the transmission. It had two large bolts with 18mm heads and two smaller bolts with 13mm heads.

Flex plate inspection plate

If your Jeep is like most, this area will be covered in mud and oil from a leaking rear main seal.  So it may take some digging to find the two small bolts.

One big issue with this task is that the bolt on the left side of the transmission will not come out unless you also remove the exhaust pipe.  However for just an inspection and tightening, you can get by without totally removing this bolt.  Just loosen the nut so the bolt can be moved back against the pipe.

Flex plate inspection plate

With the other bolts out you can pull the plate back enough to see the flex plate bolts and get a 15mm box end wrench on them to snug them up as necessary.  If you want to work in a torque wrench or put on some locktight, you will have to remove the exhaust pipe.

Once the bolts are tight, you can turn the transmission with the wrench on the bolt. There is just enough room to bring one bolt to the bottom and be able to access the next one at the top of the opening.  There are four so keep count and you will know when they are all checked.

Inspect the flex plate for damage while you are there. If the bolts have been loose for a while the holse my be elongated or the plate cracked.  If this is the case, you will have to remove the transmission to replace the flex plate.

Georgia Traverse Trail

Running a portion of the Georgia Traverse

Tom and I decided to try out the Georgia Traverse Trail that runs across the northern part of Georgia. It is documented on the web site GeorgiaOverland.com.

For our first excursion, we chose the section that is between our homes.  There are two alternate paths around the Cohutta Wilderness area – since the road through was closed years ago.  We decided to run both and make a loop.

We met in Eton and began the adventure in Crandle.  I had taken a few minutes to study the map at home and had planned to use my phone to navigate. However, I found it very hard to view the maps on mobile.

So we promptly got lost on the first turn.  After ending up at the Cohutta Spring resort, We made a second go and found 630 to Conasauga lake.

We made our way up the mountain and took the north fork toward Murry Lake.  We never did see the lake however.  Not sure where we missed it.

We took a right on old Hwy 2 and up into Tennessee at the Jacks River Bridge.  This was familiar territory to us form having worked and raced in the Cherokee Trails Rally. 

We paused at the little waterfall alongside the road that is an old railroad grade.

We then made the sharp right up Big Frog loop.  We followed the loop all the way to Peavine road.

Then we took Peavive across the ridge following the south side of the Ocoee River.  We debated returning to pavement at Ocoee#3 powerhouse but decided to continue and make the gravel loop.

Just past Tumbling Creek Campground we turned right to head south. This was new territory for me.  The area by the creek was very popular with every pull off occupied by people playing in the water.

Just after got back to the wilderness area, we encountered our first and only obstacle of the day. A tree across the road.

After some debate, I decided to hop across with Tom spotting.  I made it fine. So I watch and took some pictures as Tom came across in his Amigo.

After we were across we made it easily down to the other side of Hwy 2.  We continued south on  and west. We had to share the road with a large group of horses at one point. At least we came up on them in a place with good visibility and a wide shoulder for them to gather and let us by.

We ended up deviating from the route slightly at the southernmost point.  We followed a sign to 411 that put us on CCC camp road rather than following Cow Pen rd.  

That worked out fine however since we got to see Bryce Falls.

We posed the Trucks for some photos before heading our separate ways.

Grading the Driveway

Since I daily drive a Jeep Cherokee XJ, I often don’t notice the condition of the driveway. I live at the end of a dead end road and I have a long gravel driveway.   Instructions to my house include, “when you get to the end of the paved road – keep going”

When I drive one of my sports cars however,  the ruts and bumps in the droveway become very apparent.  The Porsche and the RX7 do a fairly good job at grading the center of the drive but it is hard on the air dams.

Grass in center of the driveway

So occasionally I have to get out my antique tractor and attach the grader blade.  Like today that usually involves working on the tractor first.  Today I had to remove and clean the carburettor before it would start.

I began by setting the blade at an angle and cutting the gravel that gets pushed to the sides of the road back to the middle. This creates a big hump in the middle of the road.  So I have to be prepared to finish once I get to this state.

I learned this method growing up on gravel roads in rural Mississippi.  I would watch as the county road graders came by once a month or so and smoothed the roads.

Back drag

After the gravel had been pulled back to the middle, I flipped the blade around backwards to do a back drag.  Allowing the curved part of the blade to ride on the pile of gravel smooths it out nicely.

Finished Drive

Now I am ready to take the Porsche for a test drive once I reinstall the brake cooling ducts.

XJ LED dash light upgrade

XJ cluster LED

Adding LED dash lights to the XJ

I recently swapped in a used cluster to replace mine where the odometer has=d stopped working. The bulbs in it were pretty dim. I decided to try using LED bulbs.

i bought these from Amazon:

The listing gave me a a warning that these would not fit my 1991 Cherokee. But since the measurements were correct I gave it a chance. They turned out to be the right bulbs.

XJ cluster LED

The trouble with the LED bulbs is that they are polarized while the originals don’t care how they are installed. Also, the LED bulbs were not marked for + and – that I saw. So I rigged up a test set up using my 12V jump box and some alligator clips.

XJ cluster LED

Now you can trace each of the copper traces on the board and see what is positive and negative, but I decided to just use trial and error. That technique got me through engineering school it can get me through five LED bulbs.
I hooked up a lead to the ground that is handily marked on the board. I touched the positive lead to the solder joint that powers the lights to test each one. See the photo:

XJ cluster LED

To make sure the bulb lit up, I removed the one next to it and peeked inside:

XJ cluster LED

If it did not light up, I just turned it around. It did not take long to get all five in the right way around.

Once the cluster was back in the Jeep I am happy with the way it looks. I also took some time to clean it all up while it was out.

XJ cluster LED
XJ cluster

How to replace the harmonic damper on a Jeep XJ

How to replace the harmonic damper on a Jeep XJ

Recently I heard a strange sound on my Dad’s XJ Wagoneer. It sounded like something hitting the fan. It took me a couple of days to find it but when I did it was obvious. The harmonic damper had come apart at the rubber joint and was working its way forward off the hub.

I caught it just in time.

I began by removing the bumper. This step is not absolutely necessary but makes the job a lot easier. Be careful with vacuum bottle in the back of the bumper when removing it.

Loosen the serpentine belt. On his Wagoneer the tension is adjusted at the power steering pump. Removing the air box makes it easier to get to the bolts.

Using a puller, remove the old damper pulley. The threaded holes for removal are in the center hub so even if the pulley is coming apart like his was, the puller will still remove it.

It is a good idea to replace the seal while the damper is out. When pressing in the new seal absolutely do not hit the end of the crank with a hammer. If you do, take time to file done the edge you created before attempting to install the new damper.

Inspect the key and make sure it is seated in the crank snout. Make note of its position.

Carefully align the key way in the new pulley with the key and try to slide it on. They pulley should fit very tight but you should be able to get it on enough to make sure the key is lined up. You will feel it if it is aligned correctly. If you can’t get the pulley on far enough to feel the key way, stop. Do not go any further. If you try to install with the key way not aligned, you will push the key out and into the timing chain behind it. You will then have to remove the timing cover and replace the damaged parts. So take your time and get the key lined up properly.

If necessary, you can heat the hub with a hot air gun to expand it enough to make it slide on the crank enough to feel the key way. you can also use sand paper to open up the hole just a bit but don’t go too far as there still needs to be a tight fit on most of the shaft.

Once the key way is lined up, press the pulley onto the shaft using an installation tool. Autozone and Advance have these in their free rental program. However be prepared for the counter guy to argue that the only have the removal tool. You can buy your own from Amazon:

Do not try to press the pulley on using the crank bolt. This will damage the threads in the crank and make an expensive mess.

Once the pulley is pressed into place, remove the tool and install the bolt and torque it to specs. You can use a screwdriver in one of the slots to hold it from turning while using your torque wrench.

Reinstall the belt and tighten. Reinstall the air box and front bumper if removed.

These clips will likely be broken on your bumper bolts: