Tag: Cherokee

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From Street Car to Rally Racer to Rock Crawler.

From Street Car to Rally Racer to Rock Crawler.

The metamorphosis of a Jeep Cherokee

Scuffy II started out as an ordinary little Jeep Cherokee. When I was ready to build my rally racer, I wanted a two door Cherokee with a five speed transmission, six cylinder engine and 4 wheel drive.

An Ebay search turned up almost what I wanted. There were only two problems. The Jeep was an 88 with the Renix engine controller and it was in Pennsylvania.

However, the price was right so I made a deal, hooked up the trailer and headed north. My dad and my son went along for support.

We arrived early in the morning to pick up the Jeep. We were expecting to have some fun loading it because the owner said the clutch would not disengage. This was one reason it was being sold cheap. I noticed that even though it was very cold out side, the little Jeep started up very easily.

I had my dad drive the trailer down the street a bit and drop the ramps. I put the Jeep in low range and hit the key. Sure enough it lurched forward and started up just fine. I had just enough room to line it up with the ramps and drive smoothly onto the trailer. I cut the key and the Jeep stopped at just the right spot on the trailer.

The owner who had gone inside to get the title came running out asking how I had fixed it so quickly. My dad just smiled and said; “He is good with Jeeps.”

This is how it looked when we first got it home:Rally Jeep Beginning XJ Cherokee

To sort it out I did a few rally crosses with it:Jeep Cherokee XJ Rallycross

I even raced it in one autocross. It really looked funny on autocross tires. It drove even worse.Jeep Cherokee Autocross racing

Soon I was ready to make the commitment to building a true rally racer. I decided on the SCCA PGT class. This class was for four wheel drive vehicles over 2.5 liters and less than 5.0 liters displacement. Minimum weight was 3000 lbs. It seemed a good fit for the Cherokee

The trouble was everything about the engine and body had to be completely OEM stock. This was tough and expensive on an old Jeep. There were many simple mods that I could have made that would have been cheaper than the stock parts, however, they were not allowed. Turbo cars were allowed external engine computers that upped their power output greatly. This put the Jeep at a horsepower disadvantage to the Subarus.

More Ebay searching turned up approved racing seats and harnesses. I traded for a roll cage and borrowed a computer and driver’s suit.

RallyJeep was born. A quick coat of racing white paint and a set of SCCA decals and we were ready for our fist race.

Rally Jeep Cherokee 100aw

Between rally races, I began enjoying the sport of off road driving. I built a cheap jeep to see how much I would enjoy the sport.
Jeep Cherokee off road XJ

Just as I was beginning to see that off road driving was huge fun and I was meeting lots of interesting people off road, the sport of rally racing took an unexpected turn. SCCA dropped their rally series and my favorite race – Cherokee Trails – was canceled forever.

An assessment of my situation showed me I had a very nice and expensive Jeep that was pretty much useless to me. I had a cobbled together collection of parts that was lots of fun to drive and a great support group that was fun to meet with.

I decided to make the commitment and convert my RallyJeep into Scuffy II the off road Jeep. This would put my lockers and 4.7 L Stroker engine to good use. And I would not have to deal with a weak carbureted engine and slipping transmission on my off road trips.

First I mounted the ARB equipped D30 front axle in place. Knowing I would add lift later, I modified the area above the control arm mounts for extra droop.
Modified dana 30 axle

Next I installed the ARB compressor.
ARB Compressor Jeep Cherokee

I also installed a lock rite equipped 8.25 in the rear that had been living under my Daily driver Jeep. I did make a couple more rallycrosses before adding the lift. The lockers really helped in the mud on rainy days.

I finally made the ultimate commitment and pulled the lift kit off Scuffy and put it on Scuffy II. My first off road trip was to Beasly knob running the 30“ tires form my daily driver. The lockers made a big difference but the small tires were just too limiting in the rocks.

Next came fender trimming and the 35” tires. The front was easy. I just traded fenders between the race Jeep and Scuffy’s already trimmed fenders.Lifted Jeep Cherokee fenders trimmed

At this point I could still go back to rally racing with about four hours work.

However, the rear tires simply would not work without more clearance than the stock wheel well provided. It took a bit of soul searching, but I finally made the commitment to irreversibly modify the rear wheel arches. Actually, I can probably still cover the mods with the stock flares and race it again if I ever choose to.

Here is how it looked with the winch mounted:
Jeep cherokee XJ off road

My first real off road adventure with the new set up was to Harlan, Ky. I was really happy with the extra control that the manual transmission gave me. Especially when going downhill. I also got to test the new winch pretty well as we used it to pull a Dodge Ram pickup up a very step muddy hill.

The most recent modification to Scuffy II has been to make the doors removable. Having the doors off greatly improves visibility and add to the open air feeling. The two door doors are also very heavy so there is a noticeable performance improvement with the doors off.
Jeep Cherokee removable doors

This Jeep gets way more use now than it ever would have as a rally racer. Driving off road has taught me many lessons about life and helped me build many great relationships.

Also, I find the thrill of conquering obstacles off road gives me every bit as big of an adrenalin rush as racing through the woods at speed. I feel really safe with the rally spec roll cage protecting me off road. Knowing the cage was designed for a seventy mile per hour impact give me a lot of confidence at fifteen MPH trial speeds.
Jeep Cherokee off road XJ 33

Overall, this Jeep has given me a lot of fun and adventure. I expect to have many more fun adventures as I learn to drive the Jeep and keep reinforcing the weak spots.

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Jeep Cherokee Shakes, Wobbles and Vibrations.

Does your Jeep shake quiver, tremble agitate, brandish, bump, chatter, churn, commove, concuss, convulse, discompose, disquiet, disturb, dither, dodder, flap, flicker, flit, flitter, flourish, fluctuate, flutter, jar, jerk, jog, joggle, jolt, jounce, move, oscillate, palpitate, perturb, quail, quake, quaver, rattle, reel, rock, roil, ruffle, set in motion, shimmer, shimmy, shiver, shudder, stagger, stir up, sway, swing, totter, tremor, twitter, upset, vibrate, waggle, water, wave, whip or wobble?

Nothing ruins a great drive in a Jeep faster than the many shakes, wobbles and annoying vibrations that can occur. These problems are made even worse when you start lifting the suspension and adding bigger tires.

The most common cause of shakes and vibrations in a Jeep are the tires. Jeeps use rather large tires often with heavy tread and with stiff sidewalls. All these factors add up to a rough ride if the tires are not well cared for.

Another common source of vibrations are the drive shafts. These rotating shafts have to be perfectly straight, and in proper alignment and balance to run smooth. Often the drive shafts can be misaligned as the Jeep is lifted or if the springs are damaged. They can be easily bent or knocked out of balance through off road use.

The most startling of all Jeep shakes is what we call Death Wobble. Death Wobble is the very scary sensation that occurs when the front wheels start to flutter like bad shopping cart wheel. The only way to deal with it while driving is to slow down until it quits. Right after your life flashes before your eyes.

Lets us look at the tires first. Other than being round and black, truck tires are very different from passenger car tires. Truck tires have much stronger sidewalls and thicker heavier tread. Both of these factors mean they may need much more weight to balance them. Also, as the tread wears the balance may shift.

Also, it is very easy to knock off a wheel weight when driving off road or sometimes move it to another place on the rim. Mud can also build up inside the rim and rocks can lodge in the tread. Any foreign object like this will cause an imbalance.

When you have a speed sensitive vibration, look first to the balance of the tires. It may be necessary to use an internal balancing system to deal with the changes in balance cause by tire wear.

Drive shaft vibrations are sometimes hard to diagnose. When you suspect a drive shaft vibration, start by inspecting the U joints. Make sure all the U joints are properly lubricated and have no slop. Replace them as necessary.

If your Jeep is lifted or has sagging or twisted springs, the drive shaft alignment may be off. Just couple of degrees of pinion misalignment can cause serious problem with the drive shaft. Also note that the alignment used for a double cardion shaft is different from that of a single tube with a single U joint at each end.

To isolate a drive shaft problem, try driving the Jeep with out the front drive shaft. The front drive shaft is easily removed and you can quickly tell if the vibes go away when the shaft is removed. To drive without the rear drive shaft, you will need some way to plug the transfer case if you have not modified it with a slip yoke eliminator. With the rear shaft removed and a suitable transmission plug in place, you can drive your Jeep using front wheel drive by placing the transfer case to the part time 4X4 setting.

Drive shat work can be expensive so it is often cheaper to swap in a used replacement rather than having yours fixed. Look for any warps or dents in the tube and replace the shaft if you find any problems.

Death wobble is normally a combination of factors. While stock Jeeps can have death wobble, it is much more common on lifted Jeeps. Bigger tires and the angle of the control arms exaggerate the already unstable inverted Y steering of the Cherokee.

Do not attempt to mask death wobble with a steering stabilizer. Replacing or adding a steering stabilizer may appear to correct the problem, but it will simply be masked until the source gets worse.

The most common source for death wobble is the track bar. Usually it wears at the frame end. This is a tie rod style joint with limited flexibility. If you have lifted your Jeep, you have already used up much of its range of motion and it will be easily damaged if the axle drops lower.

To test the track bar, place your hand on the axle end joint and have an assistant move the steering wheel back and forth. If you feel any play in the joint at all, the track bar needs to be replaced.

Note that many aftermarket track bars have poor life expectancy. I have found the ones from Crown Automotive to be well made and reasonably priced. Let me know if you need a quote on one.

Another common cause if the track bar is OK is wear in the control arm bushings. The axle end upper joint is sometimes damaged by oil dripping from the air box if blow by is an issue. The bushings are difficult to replace in the control arms them selves and it is sometimes cheaper to buy new control arm than to buy the two bushings.

Other things to check are the bolts that hold the steering box to the frame and slop in the pitman arm. Worn tie rod ends can also contribute to death wobble.

In extreme cases or where you have to drive a Jeep that is subject to death wobble, try altering the steering alignment a bit. Toe out will usually stop death wobble. It will wear the tires, but it will stop the wobble. I also fixed one by removing all the caster shims from the lower control arms.

Follow these guidelines and you will be driving a smooth running vehicle that can take you anywhere. Just realize it will take some attention to details to keep your Jeep running smooth.

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Jeep Repairs

This weekend I helped Jenny change the transmission mount on her XJ. While we had the cross member out we decided to remove the transfer case lowering blocks. This drop was put in to match the tapered lift blocks that came with her lift kit.

We removed the spacers and replaced the tapered blocks with flat blocks.

A test drive showed that the drive shaft vibes were back. I guess the drop is necessary for the 92. I have the same lift on my 88 with no transfer case drop and no drive line vibes.

We spent Sunday afternoon putting the transfer case spacers back in and replacing the flat blocks with the tapered blocks.

The drive line is now smooth again.

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Jeep Cherokees

On of my passions is Jeep Cherokees.  All my family drives XJs.  Mine is a 91 four door with over 300,000 miles.  My ex rally racer now turned off road Jeep is an 88 two door with a 4.7L stroker engine.  Now with a three inch lift and 33 inch Maxxis Buckshot tires.

My older son drives an 88 XJ Wagoneer with a 4.7L Stroker motor.  A real surprise at stoplights when this wood grain sided, white wall tired monster walks off and leaves muscle cars!  His wife drives a 96 Cherokee Country.

My younger son has a 91 like mine except his is green.

My Wife drives a 99 Cherokee Classic.  Our friend and business partner has a 92 XJ with a 3 inch lift and 31 inch Maxxis Buckshots.

To read more about our Jeeps, see: http://mikestrawbridge.com/jeep-cherokee-off-road.shtml