Click for Coverage
Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler

Jeep Tech Questions - Your Jeep

Posted in How To on April 1, 2008
Share this
Photographers: Pete Trasborg

How come you never see a Currie Antirock swaybar on YJs? One exception was on a YJ in JP Magazine's September 2007 issue. Is the Antirock a bad choice on a YJ? I drove a custom buggy for a day in Moab. It had Antirocks front and rear and they controlled body roll like no other. This only made me want them on my YJ. Maybe leaf springs and Antirocks are a bad combo. Help me out here.
"Jeep Boy"
Logan, Utah

It's not that it's a bad combo. It's just that most people feel there's enough inherent friction within the leaf pack to give enough stability for most off-road situations. In short, they just don't need them. At least, that's what most people feel.

However, if you want to run a swaybar off-road, the Antirock is, in my opinion, the best choice. It will allow more flex with littleto- no binding and has several provisions for increasing or decreasing the firmness of the bar.

Help a poor student Jeeper, please! I'm going to UTI right now in Ilinois, but I've recently started my first buildup ever on an '87 YJ. I'm looking to drop a Chevy 350, TH350, and the stock NP231 into it in place of my beat-up 4.2L. I was also thinking of the Skyjacker 6-inch monoleaf suspension system-all this on a budget. What I'm wondering is where I might find all the mounts and adapters for the engine and trans, the place where I may find the best deals on the driveshafts, and what other things I might run into.
Jason Jahnke
Hanover Park, Illinois

There are a few issues you'll need to overcome. First, those monoleafs are most likely going to bend and pretzel as soon as they get some real power applied to them. When they do, they'll most likely take out the pinion yoke and/or driveshaft, so plan that into your budget. It's my opinion that a regular set of Skyjacker multi-leaf packs will do much better with moderate-to-big power levels and serious off-road use.

Advance Adapters, Novak, and even Trans-Dapt make purpose-built and universal motor mounts that will allow you to drop that engine in your chassis. As for the TH350-to-NP231 adapter, you're going to need to come up with the tranny-to-t-case adapter and either a spud shaft or new t-case input gear that matches the tranny output shaft. They're about $500 new from Novak or Advance Adapters, but used ones pop up on the Web all the time. Don't forget eBay and Craigslist, as well.

As for driveshafts, don't totally discount your local guy when shopping for the best price. Remember to factor in the cost of shipping into the equation. I'm not familiar with Ilinois shops, but mail order guys like JE Reel, and so on are a good bargain. Check the back pages of Jp Magazine and shop around. At that lift, you'll need a CV shaft in the rear and most likely in the front. You can nab a CV front driveshaft out of a TJ and have it retubed to save a bunch of money. For example, a new CV driveshaft may run $350 from a builder, but it'll cost $20 for the TJ driveshaft at the junkyard (or online) and about $80 to have it retubed. The downside is that you won't be getting new components, and for that price, the tubing probably won't be that thick.

Don't forget the other stuff you'll probably need, like a larger radiator, power steering lines, throttle linkage, tranny kickdown parts, exhaust, and so on.

I have been wrestling with the overheating blower switch for several months. Seeing your article "Retardant" (October 2007) had me hoping that I had finally found the solution. However, it seems to me that replacing the offending blower motor might be a better solution. You state that your inserted relays ended up operating at nearly the same temperature, (116 vs. 122 degrees) as the original switch, but you didn't seem concerned about this. Wouldn't the wires, cut to insert relays, still heat up dangerously, even with the relays? Your comments on this are greatly anticipated.
John Maguire
Ontario, California

Yes, replacing the blower motor needs to be done. We hadn't done so by the time we went to press, but did in the weeks afterwards.

As for the heat with the relays and wires, relays run under the hood at 200-plus degrees all the time, and most automotive wires are good for 300 to 600 degrees, depending on the quality of the wire and/or insulation.

In the stock system, the switch is the weak spot; once you pull the old one apart and look at it, you'll see-it just isn't rated for any kind of amperage. And, once the switch is overloaded, the connector won't be far behind in the melting pile of electrical stuff. How the engineers thought it would be a good idea just boggles the mind. Maybe in a sealed environment, it will work fine for whatever the designed life cycle is, but there are so many Jeeps out there with this problem that there is obviously something not taken into account.

So, definitely replace the blower motor, but also do the relay trick (adding however many you think is appropriate). Look real hard at the stock connections and switch, replacing them as needed too. If you can swing it, do them all at the same time. If not, start with the relays and go out from there as your budget allows, like we did.
-Pete Trasborg

Hello I'm currently overseas, but I have an '89 YJ back home with my family that I been working on. It currently has a 2.5L 4 cylinder engine that is starting to die out. My father has found a 2.5L from a 1995 with the computer and the whole deal. I just don't know if it will bolt up to the transmission.

Another question is what would be required to convert to a 4.0L six cylinder from what I have now? It's all stock except for the lift, which I know doesn't really matter all that much. Right now, the thing only tops out at 55-60, and I need it to be able to not have a issue on the highway when I bring it back to Fort Knox, Kentucky, from Lake Elm, Minnesota, which is about an 18-hour drive.

Please, if you can tell me anything at all, it would be much appreciated. I like the condition and my year, and I don't want to have to sell it to get a different one. It's my first Wrangler, and I was happy to get it. I'd like to keep it and make it truly what I want. I don't want to spend the money to make the new one look like the one I have now.
James Raykowski
Via e-mail

The '95 engine will bolt to your '89 transmission and motor mounts. You'll need to run the '95 front accessories (power steering pump, alternator, and so on) and the '95 wiring harness and computer. I think you may also need to use the in-tank fuel pump for a '91-up Wrangler.

You can put the 4.0L in, but it's a lot more work. You'll need the 4.0L AX-15 transmission since your 4-cylinder AX-5 won't bolt up and isn't up to the power the 4.0L puts out. You'll also need to lengthen the fuel lines (or just run 4.0L lines), different throttle cable, radiator, hoses, 4.0L front accessory package, and the wiring harness and computer for the 4.0L. Hesco ( has 4.0L conversion kits, but they're not exactly cheap.

Honestly, unless you've already built your YJ up with high-dollar axles, lift, and so on, it's really not worth it to swap from a 4-cylinder to a 6-cylinder. It's a whole lot easier and more economical to just buy the 4.0L Jeep to begin with.

I just bought an '00 TJ and was doing a routine oil change. I am new to Jeeps and am wondering how you add oil to your engine. I know where to do it, but I can't figure out how to open the hatch. Does it just unscrew or snap off? And do you need a special tool to do it? I know it is a stupid question, but I can't figure it out.
Cape Elezabeth, Maine

There's a twist-off fill cap located in the center of the valve cover. Twist it counter-clockwise to spin it off. If it just spins and clicks without coming off, then the plastic ratchet mechanism inside that's designed to prevent overtightening has broken. You'll have to buy a new cap at the Jeep dealership. To remove the broken cap, pry the top of it off with a flat-head screwdriver. Then you can use a pair of pliers or some other tool to remove the threaded plug that will be left in the valve cover.

In all of your story lines, you never say anything about the transmission in my '79 CJ-7 Golden Eagle. It's a T-18 four-speed with real low First gear. Is this a good tranny? I think that it is a Ford truck tranny, but I would like to know more about it.
Ted Kent
Belle Vernon, Pennsylvania

Your T-18 is an absolutely great transmission. It's a highly sought-after piece. Jeep used them sparingly in CJs and fullsize pickups and Wagoneers, so there's a slight chance it's original. Or, it could be a Ford T-18 that was installed somewhere in the Jeep's past. The only real way to know is to pull the tranny and measure the input shaft. The Ford versions have a 6.5-inch shaft, while the Jeep versions could be any one of 14 other configurations. Regardless, unless you're swapping main shafts or input shafts, both versions use the same gears, bearings, and synchros.

Your gear ratios should be as follows: 6.32, 3.09, 1.69, 1.0. Jeep did use a 4.03 First gear, but a few CJs got the granny low gear.

Got a tech question you're just itching to get answered? Send it on in to Jp Magazine, Your Jeep, 6420 Wilshire Blvd., Los Angeles, CA 90048, or e-mail

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results