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Answers to all your Jeep questions

Posted in How To: Tech Qa on November 1, 2015
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Cool AW4
You solved one issue on my ’01 XJ before, so here I am again to see if you can help me again. I’m trying to locate a high-capacity transmission pan for my XJ. Somebody has to make them. Wheeling out here in the Southern California desert cranks up the heat on those transmissions.
Name Withheld
Via email

There are a few things to consider before adding an extra-capacity pan to an automatic transmission. Ground clearance could be an issue on some applications, as the pan of an automatic transmission usually isn’t very stout. A properly placed rock can easily tear through the stamped steel, so you really don’t want it any closer to the ground than what is absolutely necessary. Another issue that surfaces is chassis clearance. Crossmembers, exhaust, suspension components, and driveshafts often pass under the transmission pan. Always check for clearance and plan accordingly when ordering a deep transmission pan.

Unfortunately, I don’t know of any extra-capacity AW4 transmission pans. However, I have seen skilled welders take two stock tranny oil pans to create one deep pan. If you go this route, you’ll also need to modify the oil pickup. Although, I don’t think it will be worth the effort. If heat is the issue, you need to increase cooling capacity, not necessarily fluid capacity. While it is true that a deeper pan and more fluid provides an increased surface area to help shed heat, the real cooling comes from the transmission cooler. Many different sized aftermarket transmission coolers are available from companies like Flex-a-lite ( Flex-a-lite also has Direct-fit Translife transmission cooler kits for many different applications, including the ’87-’01 XJ Cherokee. If you don’t go with the Direct-fit kit, I’d recommend that you stuff the largest transmission cooler you can fit behind the grille. You might even consider mounting a cooler elsewhere under the chassis with an electric fan, depending on the kind of off-roading you like to do. For deep water crossings and regular mud baths, you’ll want to keep the cooler clean and up high. A mud-caked radiator or transmission cooler can’t dissipate heat.

If you think the transmission is running hot, you might consider adding a fluid temperature gauge. Generally, it’s best to mount the sending unit for the gauge in the transmission pan to get an accurate reading. In some cases this is just not possible so you can mount the sender in the oil return line coming from the cooler and headed to the transmission.

If you don’t regularly deal with freezing temperatures, you might consider disconnecting and bypassing the in-radiator transmission cooler and only use external coolers. Newer engines typically run at about 200-210 degrees. In some cases, the radiator coolant that was pulling heat out of the transmission fluid via the in-radiator cooler, could be heating up the transmission fluid. An automatic transmission will last longer if you can keep the fluid at about 175 degrees. In some racing and cold-weather applications, multiple transmission coolers are used along with a remote thermostat. It’s plumbed so that one or both coolers are bypassed until the fluid temperature reaches a certain level. This helps maintain a consistent fluid temperature regardless of ambient temperature and vehicle use.

Towing Location
Love the magazine. I recently purchased a used car trailer for transporting my Jeep to the hills with all my camping stuff. I'm getting older and need lots of stuff to be comfortable these days. How do I determine the correct location for my Jeep to sit on the trailer? I would like to build a storage box on the trailer in front of the Jeep, but I don't want too little tongue weight on the trailer. Keep up the good work.
Steve F.
Via email

First, you need to make sure that your loaded trailer sits level. This may require the use of a drop hitch in some applications. The proper location for strapping a Jeep to a trailer is dependent on many elements. Trailer length, weight, trailer axle location, tongue length, and so on, are all determining factors. If you pull the Jeep too far forward, the rear suspension of the tow rig will sag and you could overload the hitch. This also causes the tow vehicle to have twitchy steering because the front suspension becomes unweighted. If you have the Jeep too far back on the trailer, you won’t have enough tongue weight. This can cause the trailer to fishtail, especially while coasting downhill.

The simple answer is that most OE manufacturers design tow vehicles to have a specific amount of trailer tongue weight to tow safely down the road. In most cases, trailers should have a tongue weight of about 10-15 percent of the total trailered load, as long as it doesn’t exceed the hitch rating. If need be, you can decrease the trailer tongue weight and spread the load out more evenly across the axles of the truck and trailer with the use of a weight-distributing hitch. It will make the trailer a little more time-consuming to connect up to your tow rig, but the stability will be worth it if your total towed load is more than 4,000 to 5,000 pounds. Gooseneck and fifth-wheel trailers should have a tongue weight of 20 to 25 percent of the total towed load. Sherline ( offers several trailer tongue weight scales that can measure up to 5,000 pounds. However, you’ll need to know the total towed load (trailer, toolbox, gear, and Jeep) to calculate the proper tongue weight when using this scale. Most of us have to experiment a bit with the Jeep location on the trailer. Adding more camp gear, fuel, extra parts, or firewood can alter where the Jeep needs to be tied down by several inches, so you’ll want to give yourself some extra space when mounting the toolbox.

Blinkin’ Light
My ’03 Rubicon's lockers have worked fine since new. However, last month, although the front locker was engaging, the light on the instrument panel kept blinking rather than a steady on. Two shops (non-dealership) have said they don't know what is wrong. I’m trying to avoid a dealership's big-buck fix. Got any ideas?
Paul Christen
Apache Junction, AZ

In most cases, the factory Jeep Rubicon lockers are reliable and maintenance-free. The Jeep Wrangler TJ locker uses low air pressure to engage. However, the wiring and electric plugs can get damaged or corroded just like any other wiring harness. The air hoses can also split and leak. First, you need check again to make sure the front locker is actually engaging. If it’s not, you may need to take a closer look at the air lines and pump. I suspect you either have a faulty sensor, damaged wiring around the axle, or possibly an electrical sensor plug that is corroded. Start with the easy stuff. Inspect the wiring to the sensor on the differential. Look for cuts and other damage. Unplug the sensor and inspect the contact terminals. If they look corroded, clean them up and smear some dialectic grease on them before reconnecting the plug. I have been told that overtightening the differential fill plug can cause it to make contact with the locker engagement ring. This could keep the locker from functioning properly. Remove the plug and use a flashlight to look inside to see if the two parts were making contact.

For anyone wondering, the JK Wrangler lockers are a bit different but can have similar problems. They are electrically actuated so they have no air lines. I have seen the sensor plunger in the front axle pop out of position. Unfortunately, this generally requires removal of the differential so that everything can be reinstalled in its proper place.

This past weekend I picked up a ’47 CJ-2A from a guy for $500, which was really for the tub, windshield, grille, and title (stating it was a ’47).

My project plan is to build a two-wheel-drive Jeep rod. The Jeep currently sits on an old CJ-7 frame (worthless), has an AMC 304 (which is supposed to run, however I have yet to fire it up), and a blown T-case. I'm not sure about the automatic transmission, as I haven't gotten completely under the Jeep to tear stuff apart yet.

I've read your past stories on the Sloppy Seconds flatrod project you built and I've also read Christian Hazel's article on Randy Ellis' rat rod. I'm gonna try to build my project on the lean side for less than $5,000. Since I can do most, if not all, of the work (and I have a great group of friends and support), I think this is certainly possible.

Where I have been struggling in my research is understanding the front suspension and how to get the front end low while still retaining a somewhat safe and stable ride. I've scoured a number of the rat rod/custom hot rod forums and have read a bunch of different suggestions. Most of these discussions target older model Fords, trucks, and not Jeeps. Finding decent pics online of how some of these suspensions are laid out has been somewhat difficult as well. I've seen a number of drop axle suspensions, but those things come with a high price. I've seen a few pics showing some sort of perch that the knuckles seem to connect with, but I can't make out the pictures well enough to see what is going on. Even though I’m not going to run four-wheel-drive, I do plan on keeping a straight axle pushed in front of the grille and frame.

I'm not looking to add airbags like Ellis did, but I don't want to have a rigid suspension either. I'm in no rush and want to take my time and build this rod right. This is certainly the largest build I have taken on, aside from rebuilding motorcycles, and while I'm excited to dive in, I'm also terrified based upon the scope of what I want to do.

I know you're busy with other projects, work, and life, but if you have the opportunity to help point me in the right direction either through other reads or articles that I can study, I would greatly appreciate it and any tips you may have.
Randy Crews
Via email

I think building a Jeep rat rod for less than $5,000 is totally doable. I had less than $1,000 into mine, not including my time of course. I acquired a lot of free used parts like the axles, engine, frame, and other components over the course of several years. And that’s the beauty of a rat rod Jeep. The coolest components are often completely worthless to off-road Jeep enthusiasts. The more old, weird, and obscure the parts are, the cooler your Jeep rod will be. I ended up using an old GM inline-six mated to an SM420 2WD transmission. The rear axle was a ’74-’86 Ford F-150 9-inch, the front axle was a Dana 27 from a Willys truck, and the frame came from an M38A1. None of the parts bolted together. Everything had to be attached with custom made brackets that I built in my own garage. For this reason alone, a Jeep rat rod is a great project to help you look at things differently and learn to assemble a vehicle from scratch.

The front suspension on my Jeep was pretty simple. I used a transverse-mounted leaf spring. I flipped it upside down and reversed the pack because the Jeep would have sat higher than I wanted if I ran it the traditional way. For more front suspension ideas try searching “hairpin front suspension.” This suspension setup is extremely common on rat rods. However, the majority of them will make use of a dropped front axle. You won’t have that luxury of using a 4x4 solid axle. It will take a little more work to get your Jeep to sit low. Speedway Motors ( has a lot of cool and inexpensive time-saving hot rod parts you can use.

I needed to clearance the front bumper a bit for the front axle. The steering was probably the trickiest part of the whole thing. I used a push-pull Willys truck steering column, steering box, and front axle, mostly because that's what I had. I had to modify the pitman arm and drag link to make it all work.

To get the Jeep really low, you'll have to do a body drop, like on Randy's. That seemed like too much work to me, so I didn't go that route. Ultimately, what I think is most important when building a Jeep rod is that you have an eye for proportions. Tires that are too big, a front axle pushed too far forward, or a windshield frame angle that doesn’t match the styling can kill a project. Take your time and look at each modification that you make from different angles. Don’t be afraid to try new ideas or completely toss an idea and start over if you don’t like the direction it’s heading. I was about half way done modifying the first frame that I planned to use before I scrapped it for a different one.

Leaky Steering
I have a ’97 TJ that has a continuing problem with leaking power steering fluid at the output shaft of the steering box. I have read where the steering box from a ’98-’99 Dodge Durango is an upgrade. Are you familiar with this upgrade and what do you think of it?
Ted Tallent
Via email

Unfortunately, both steering boxes are very similar in design. In fact, they use the same sector shaft seal part number that you seem to have a problem with. Swapping to the Dodge box will not solve your problem. The only real difference between these two steering boxes is that the Dodge box has a slightly quicker steering ratio than your Jeep Wrangler steering box (3 turns lock-to-lock versus 3 3/8 turns).

Generally, the sector shaft seal only leaks if there are other parts inside the steering box that are worn out. Simply replacing the seal won’t fix the root of the problem. There is likely some sector shaft slop caused by wear. I recommend that you get your hands on a quality rebuilt steering box for a TJ Wrangler. This should solve the leaking problem that you are having and will help avoid any handling problems that can be caused by a worn steering box.

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