What's more reliable? CJ's or Modern Jeeps?

[jzak]

I just had a friend who got his JK towed, and it got me thinking. What is generally more reliable CJ's, or the more modern YJ/TJ/JK's. On one hand the CJ's are obviously much older, which usually means more things are going to break, but on the other hand modern Jeeps are made of many plastic parts, with more complex mechanical and electrical systems.

Obviously, asking this on a CJ forum, the feedback is going to be a little biased, but I would love to get your opinions.

Thanks!

Josh

 

[Belizean]

If we are going with more reliable, which can mean different things to different people, I would say the CJ. Less complicated and easier to fix on the trail. A lot of electronic things can go bad on the newer vehicles. Just my thoughts

 

[gr8dain]

This is a loaded question. It has taken me a lot since 2010 to get my CJ to a pretty reliable daily driver. And it has been a daily driver since I bought it in 2010. Have things broken along the way? Of course. Have I fixed them? Of course. And I generally enjoyed it despite the pressure to fix it immediately so that I could get to work the next day.

There was a period that I drove a JkU as a daily driver while I was doing a frame swap on the CJ. And that was just hop in and no worries. It never broke down. Ever. Oil changes. That is it. We sold it. [emoji12]

So, The JKU was much more reliable. But not as fun.

 

[JeeperChris]

Interesting question. I think we would have to look at the timeline of how many years any given CJ went from day one out of the factory until it broke down with a problem that could not be quickly fixed by the driver, vs., the same timeline and criteria for a given newer model. That data might actually be floating around on the web somewhere so this may actually be an answerable question.

 

[gr8dain]

Agreed my reply was comparing a 1984 CJ to a 2015 JKU. So I would assume that the CJ was very reliable back in the mid 80s. But I did not read you question as to which was more reliable when new. I read it as an old cj now vs a less old model now.

Oh and I had a YJ from 2006 to 2010 that gave me zero problems. And was as reliable as a top every day.

 

[jzak]

Thanks everybody for your opinions!

Interesting question. I think we would have to look at the timeline of how many years any given CJ went from day one out of the factory until it broke down with a problem that could not be quickly fixed by the driver, vs., the same timeline and criteria for a given newer model. That data might actually be floating around on the web somewhere so this may actually be an answerable question.

I think we need to hire a Think Tank to do a Jeep reliability study. I guess when we're talking about reliability it comes down to the powertrain. Are the older Hurricane, Dauntless Buick 225 V6 and AMC engines more reliable? I know the AMC 258 i6 / 4.2l is work horse.

 

[Belizean]

Thanks everybody for your opinions!




I think we need to hire a Think Tank to do a Jeep reliability study. I guess when we're talking about reliability it comes down to the powertrain. Are the older Hurricane, Dauntless Buick 225 V6 and AMC engines more reliable? I know the AMC 258 i6 / 4.2l is work horse.

I've got the Jeep 4 cylinder with 238,000 miles and have never had to go inside of it to fix it. Still working well. Just change the oil on schedule

 

[hagar]

I've got the Jeep 4 cylinder with 238,000 miles and have never had to go inside of it to fix it. Still working well. Just change the oil on schedule

I guess when a 2015 JK turns 35 years old and has 238k miles we will have an answer.
Personally, I don't see JKs lasting 35 years........

 

[Lumpy Grits]

Depends on how much of a 'wrench' the owner is.
I have towed out many a 'Fiat' to the road, to be picked up by a flat-bed tow truck.
I've been drive'n my CJ for over 34 years now.........
LG

 

[Only in a Jeep CJ]

I've worked on many of the newer Jeeps and here is what I've seen,

The YJ is too close to the CJ in its design, running gear, and reliability for this comparison.

The TJ/ LJ has several reoccurring issues. There is a ton of heat under hood that wrecks the computer/ecu by the battery. The gauges will sweep back and forth and it will shut down, but then it usually restarts. The blower motor speed switch heats up and melts at the plug contacts so you have to buy a new 3 switch panel. The 05/06 has an OPDA (oil pump drive assembly I think) that has an oiling issue via a misplaced O ring. When it fails, it strips drive gears at the cam and stops the oil pump... then the engine goes out.
Tilt cables in the seats are always breaking, Cooling issues and radiators gummed up, binding tcase shift linkages, O2 sensors always going out, Transmission noise, failed pilot bearings/throwout bearings, and other little stuff. I've seen single wire shorts stop a TJ in its tracks.


The patterns I see in the JKs are failing front driveshafts at the t case joint, oil coolers failing at their O rings. (these are in the center of the engine and a pain to swap out), failing sway bar disconnects from water getting into the circuit board, front seat tilt torque bars stripping out on one side, air pockets in the motors causing over heating issues, corroded aluminum door hinges, and other weird stuff.

Now to be fair, lets talk about the CJ. I'm going to focus on the late CJ (82 to 86) because that's what I've been daily driving for the last 28 years.
Spun rear hubs (2 piece axle shafts), reoccurring carb tuning, wiring issues, headlight switch problems, rust issues, etc.

In general, when the CJ has a problem, it will make a noise at the source, or have a switch problem cut in and out, but still get you home. IF it does die, its usually an easy fix IF you know your jeep and are mechanically inclined.
With the TJ/JK, you better own a code reader as it can have a part go out and that's it.

So FOR ME ONLY, in 28 years, I have only walked away from a CJ twice. Once was me running out of gas and the other was a small engine fire that I was lucky enough to put out right away.. I cut out the bad wires, ran a jumper wirer to start it and drove it home the next day.

Yes, I'm still daily driving CJs. An 83 Scrambler right now.

 

[jzak]

I've worked on many of the newer Jeeps and here is what I've seen,

The YJ is too close to the CJ in its design, running gear, and reliability for this comparison.

The TJ/ LJ has several reoccurring issues. There is a ton of heat under hood that wrecks the computer/ecu by the battery. The gauges will sweep back and forth and it will shut down, but then it usually restarts. The blower motor speed switch heats up and melts at the plug contacts so you have to buy a new 3 switch panel. The 05/06 has an OPDA (oil pump drive assembly I think) that has an oiling issue via a misplaced O ring. When it fails, it strips drive gears at the cam and stops the oil pump... then the engine goes out.
Tilt cables in the seats are always breaking, Cooling issues and radiators gummed up, binding tcase shift linkages, O2 sensors always going out, Transmission noise, failed pilot bearings/throwout bearings, and other little stuff. I've seen single wire shorts stop a TJ in its tracks.


The patterns I see in the JKs are failing front driveshafts at the t case joint, oil coolers failing at their O rings. (these are in the center of the engine and a pain to swap out), failing sway bar disconnects from water getting into the circuit board, front seat tilt torque bars stripping out on one side, air pockets in the motors causing over heating issues, corroded aluminum door hinges, and other weird stuff.

Now to be fair, lets talk about the CJ. I'm going to focus on the late CJ (82 to 86) because that's what I've been daily driving for the last 28 years.
Spun rear hubs (2 piece axle shafts), reoccurring carb tuning, wiring issues, headlight switch problems, rust issues, etc.

In general, when the CJ has a problem, it will make a noise at the source, or have a switch problem cut in and out, but still get you home. IF it does die, its usually an easy fix IF you know your jeep and are mechanically inclined.
With the TJ/JK, you better own a code reader as it can have a part go out and that's it.

So FOR ME ONLY, in 28 years, I have only walked away from a CJ twice. Once was me running out of gas and the other was a small engine fire that I was lucky enough to put out right away.. I cut out the bad wires, ran a jumper wirer to start it and drove it home the next day.

Yes, I'm still daily driving CJs. An 83 Scrambler right now.

Thanks Bud! I couldn't ask for a better answer to my question.

 

[gr8dain]

This might change my initial response. I think the timing jumped. And the motor was tough to turn over and the starter literally blew up as well as ground off some teeth on the flywheel. It has stopped being my daily driver for now.

 

[Belizean]

This might change my initial response. I think the timing jumped. And the motor was tough to turn over and the starter literally blew up as well as ground off some teeth on the flywheel. It has stopped being my daily driver for now.

I think you might be a little jaded now ! Yours might have been treated like a rented mule long before you ever had it. I wouldn't hesitate to jump into mine and drive across the country right now. But then again I wouldn't hesitate to jump into my Toyota with 200K miles and do the same.

 

[duffer]

This is apples to oranges comparison. With 7+ years on the JKUR I can agree on the code reader but my experience with that so far has been very positive as it has taken me right to the problem source each and every time. At no point has the JK needed the service of a tow truck but it has been in the limp mode default several times. Mechanically, absolutely nothing has broke and we wheel it reasonably hard.

On my CJ's, the only time either has needed the service of a tow truck was when I ventilated the block of the 327 in my 3B. It wasn't the fault of anything Willys Motors did but rather the known thin cylinder wall at the bottom of sbc cylinders 5/7.

Assuming all the Jeeps of this comparison are well maintained, I don't think there is much difference as to reliability. The real difference, IMO, is driving them to the trailhead. The JKUR is stable at 80 mph. Both my CJ5 and 3B have been there too but not something one probably wants to do on a continuous basis.

 

[mitchelllogic]

JUST ME.....
I'll take my CJ any day. Wrenched every bolt on it though. Not an original part in it anymore (aside from the grill, hood, block, frame, seats, carriers, Tcase, skid plate, and rollbar).
For me it's more about what I can fix with a tool roll now.
Everything in the CJ is accessible.
Lots of failures can be "rigged" to get you home.
You can troubleshoot an issue in minutes.
Mines neutered and dead simple now so any issue is a quick find.
Most failures these days are PEBWAS or (problem exists between wheel and seat) or TOFB (throttle on floorboard)
Agree with the trailhead comment though.

(Rented a JL for a week recently. Plush. Computer in it dumped the dash three times. No gauges. Wouldn't move. So after taking a shower, apologizing to my CJ, and buying her new brake shoes. We were back together again.)

Sent from my Pixel 2 using Tapatalk

 

[Mrpeter63]

It's hard to compare the older versus newer. The older, CJ and YJ, being basically what would be considered a "Stripped down" model at today's standards. No Cj owner ever took their Jeep back to the dealer because their seat heater stopped working. I'm sure there were plenty of new CJ and Yj owners back in the day that drove off the dealer parking lot and had nothing but issues. Just the way it is with assembly line production, you get good ones and bad ones. They just hope the bad ones are few and far between. If you want to compare motors, yea the AMC 258 i6 / 4.2l and the later 4.0 version are very rock solid. Look around, there's an old running XJ on every corner. I know there was a period around 2012 that the Chrysler had an issue with there V6's throwing rods around 120,000 miles but that was also a hit n miss thing and not just a Jeep thing. So, as far as drive train issues go they are probably fairly equal, when you take into account the era they were produced in. Engine technology today is so far ahead of where it was back then. You just have to take into account that there are a ton more TJ, JK, and JL owners out there then there ever where CJ and YJ owners. The more vehicles produced the more issues that pop up.....