The first Wrangler was introduced amid tighter CAFÉ regulations, tighteremissions laws, a fear of the new computer-controlled engines, and a recent witch hunt that killed the CJ-5. It was a Jeep of many compromises to many groups and some will argue that it met none of the pundit's demands well.
We can remember being down on the new Jeep, too. "No more CJ?"; "What is with those headlights?"; "I can't fit a 31-32-inch tire anymore?"; "Where did the tailgate go?"; "What is with this plastic junk for a dashboard?" Yeah, we were as angry as everyone else.
It didn't take us long to come around and now we see how much of an improvement the Wrangler was over the CJ that preceded it. With a better frame, a galvanized body, wider and longer springs, the big picture was really nice, even if none of us could see the forest for the trees. After a few rough years, the YJ really hit its stride and the Wrangler ran with the same basic powertrain for 15 years.
Much of the Jeep community has come around too, but not before the TJ popped up and eclipsed the YJ. The buy-in price for this cornerstone of the Wrangler marque is low and there is a lot of value, but like any other vehicle, there is just a bit of caveat emptor. So sit back, strap in, and run with us as we run down 10 of the most common chinks in the YJ armor.
The Central Axle Disconnect system or CAD was a response to two separate inputs. On the one hand, Jeep had to meet better fuel economy goals, and on the other hand, Jeep was looking at a consumer who was sick of locking and unlocking hubs. Who wanted to get out of the Jeep when the going got rough?
Sounds nice, doesn't it? Better mileage and no need to get out of the Jeep to engage 4WD must be a great idea. The issue is, the CAD system straddled the crossroads of the dawn of the chain-driven T-case and a change in the demographic of the typical Jeep buyer. It was a system that was outdated as soon as it was introduced. A chain-driven T-case by nature can absorb more shock than a gear-driven case, spinning the planetary doesn't suck up that much fuel, and the CAD really wasn't needed. However, for 46 years there were manual hubs to disengage the front axle, so some disconnect must still be needed, right?
The problem is that the system relies on vacuum and electric for everything to work. Dried out lines or melted connectors means something has gone wrong with it. Most often you will be stuck where you should have been able to drive out of.
Getting rid of the system is the best way to fix it. Hand-me-down TJ or XJ axleshafts will work, but you'll have to pop the carrier out to install a new inner axleshaft seal. The easiest way to get around the troublesome system is to install a 4x4 Posi-lok that replaces the vacuum portion with a cable that you engage from your seat. If you are an abusive driver, however, the cast CAD portion is prone to cracking and leaking. You can use an XJ front high-pinion axle, cut off the XJ brackets, weld on leaf spring mounts, and swap your gears, outer knuckles, unit bearings, and brakes over.
Flatter, more supple springs made for more lateral and vertical movement than the old CJ springs ever had. The flatter springs necessitated a sway bar, and a track bar was added front and rear. Both items became standard for the entire Wrangler line.
The problem with the track bar is that it moves in an arc, while the leaf springs want to move straight up and down. The dissimilar movement puts unneeded stress on the frame and axle. Over time, we've seen brackets tear off the frame and even break the frame. Ditch the track bars and never look back.
The Wrangler got the same anvil-strong 258 engine that graced the CJ it replaced, but for '87-'90 it was also saddled with a two-barrel computer-controlled Carter carburetor. It ran fine when it left the factory, but once it started going bad, it was very hit-or-miss if the local dealer would be able to get it running right again.
We know now that a common issue with the carburetor was that the steel throttle shaft would egg out the aluminum housing over time. Other issues these Wranglers face today are largely associated with emissions. Cracked vacuum lines, blown-up or barely-working smog pumps, clogged catalytic converters from the wonderful carburetor, and more. The solution is to ditch the factory carburetor and most of the spaghetti-like vacuum lines.
There are several ways to do this, and all of them will result in a better-running Jeep that pollutes less than it does with the worn-out parts. The cheapest way is to use a two barrel Motorcraft carburetor with the 1.08-inch venturis, Trans-Dapt adapter plate number 2086, and bolt it on. Another method is to install a Weber carburetor. The Weber is available as a kit from 4WD Hardware and Quadratec, but check your local emissions laws first.
Our favorite way to ditch the Carter is to install a 50-state-legal Howell fuel injection conversion kit. It replaces most of the archaic emissions stuff with a closed-loop throttle body system that will make your Jeep run stronger and more efficiently than it ever has.
If you have a hardtop-equipped Wrangler, this site is familiar to you. Due to a design flaw almost all of these doors crack by the vent window and let water down into the door which can lead to the bottom of the doors rusting. Welding it back up and grinding the weld down is the order of the day. However, if that is all you do, it will just crack again over time.
The solution is to pull the vent window and roll-up window out , cut a plate to fit behind the cracked area and weld it in. either stitch weld it from the back, or drill some holes through the front and rosette weld it into place. Be mindful when you cut and install the reinforcing plate to avoid interference with operation and installation of the windows. The added reinforcement should keep your doors from cracking long into the future.
One thing Jeep didn't get right until near the '94 model year was the hydraulic slave cylinder. While the internal hydraulic throwout bearing setup was better than the mechanical clutch linkage of the CJs, they can still cause problems. If yours hasn't gone out yet and resulted in clutch fluid dripping from your bellhousing, don't worry, it will.
If you have the '87-'89 Peugot transmission, you have no choice but to replace the hydraulic throwout bearing. However, if you have an AX-5 or AX-15 you can convert it over to the later setup fairly easily. Look for '94-and-up parts off of the same model transmission and pick up the bellhousing, slave cylinder, input bearing retainer, throwout bearing, and clutch fork from a junkyard or eBay. When your hydraulic throwout bearing pukes its guts out, you'll be all ready to swap in the good stuff.
The fuel gauge on many YJs either bounces or doesn't read true. If you are like most YJ owners you make sure to use your trip odometer. Basically the issue is that you've got an electrical contact that has gone bad somewhere. The first thing to do is pull your center five gauges out of the dashboard, remove the nuts that are holding the printed circuit board onto the back of the housing, clean the contact area under the nuts with a Scotch Bright pad or very fine sandpaper and put it back together. If that doesn't work, it is likely your sending unit or the ground for the sending unit. Either way you will have to drop the tank to get to it. Inspect and clean all connections and see where that puts you.
If the connections are OK, yank the sending unit and make sure there is no corrosion where the arm contacts the coil. Clean the coil the same way you cleaned the printed circuit board.
Since doors were optional on CJs, the mirrors came mounted to the windshield, if they were installed at all. The new civilized Wrangler doors were standard, as were mirrors and except for part of '87, the mirrors were mounted to the doors. This makes them easier to adjust, and larger mirrors that were on both half and full doors are actually useful.
In some states it isn't even legal to pull the doors off, but most are fairly accepting of doorless Jeeps. Once you take your doors off, however, the mirrors are gone and you are illegal in every state. There are mirror-relocation kits and quick mirror kits, but we'd rather not mess with yet another thing to go topless and doorless. So we turn to Omix-Ada for a set of CJ replacement mirrors with optional aluminum bushings to cut down on flutter.
Then we drill and tap our windshield hinge to accept bolts and install the mirrors just like they would have been on a CJ (minus torx bolts). Make sure and get the mirrors and arms from a reputable company, as some of the CJ replacement mirrors won't hold adjustment at all.
The sheetmetal screws that hold the top to the windshield frame always wallow out. Regardless if your Wrangler is equipped with a hard top or soft top you likely have this issue. The only possible way to avoid this is to leave the top on all the time, and even that is not a fail-proof solution.
If you have a soft top, the header reinforcement kit from RnVentions works great to fix the stripped-out holes. The kit comes with nutserts, a special riveting tool, new machine screws, and weatherstripping.
If it is a hard top that is bothering you, the Kwik Kit from Lange is a nice solution to the problem. The kit converts the sheetmetal screw fastening method over to a clamp-style like the TJ enjoys. The clamps don't use the old holes and by actually clamping the front of the top down, it provides a better seal and can help fix air and water leaks.
The soft top tensioner bracket is riveted onto the soft top bow from the factory and the bolt that holds the tensioner rod in isn't fastened to the bracket, just pressed or threaded through it. The problem is, with the bolt loose and the bracket loose, the top doesn't hold tension. The nut will work its way off the stud or the rivets will pull out eventually, letting the tensioner rod fall off the bow. There is nothing worse than cruising down the road at 70 mph and losing tension on the top. The sonic boom that can result is quite startling.
Take the entire bracket off the bow and check the stud. If the threads are shot, pull the stud out and replace it with a 1/4 x1 bolt. Weld the back side of the stud or bolt so it will never spin, and then weld the bracket back onto the bow assembly.
Once that is fixed, you might notice your top still doesn't stay tight because your stock tensioners keep popping loose. With no way to lock them in the open position, it is a common, but avoidable, irritation. The adjustable top tensioners from 4WD Hardware lock in the open position to fix that problem and allow for fine adjustment of your top so that it fits snugly.
Win Some, Lose Some
The nice thing about the YJ is also one of the bummers about the YJ. The wide, flat, and long springs give good flex and a great ride for a leaf-sprung vehicle. If your YJ is still running the stock springs, they are sagging by now.
Old Man Emu makes some great military wrapped and shot-peened springs for the YJ that are available in 2 1/2 inches of lift height. The ride is close to stock, but they can handle some weight and are built to take abuse.
Another way to go is to get another set of stock springs and build your own pack. We normally just take the main leaf from the donor pack, lop off the spring eyes, and install it in the leaf pack that is already on the Jeep. That usually gets us about an inch of lift, and the ride quality is close to stock. There were a lot of different springs for the YJ, including four-cylinder and six-cylinder springs as well as soft top, hard top, and heavy-duty springs. Your adjusted ride height might vary depending on how sagged-out your YJ is and what donor springs you get.