Flag waving: XJ AMC 80s vs Chrysler's era XJs

[Jim D.]

See lots of JeepFreaks with older XJs. Good for you; I love them. But: I just want to say something. I had an 87 XJ Pioneer, used 4WD-extremely in Ecuador. Name the problem: I had it. Towed 3 times (twice clogged fuel filter, once because - honest - the clutch pedal broke off!!); radiator hoses rubbed through (in the boonies - ever have the out of body experience of smelling antifreeze when you're miles from civilization?? "That can't be me; I'm dreaming." Thank goodness for racer tape.); all suspension bolts loose after a tough off road weekend; hood latch catch broken; rear aux. light personally installed by me, ripped out of the fiberglass rear door by a thief the first night I parked the car in the street; exhaust manifold bolts cracked; I could go on, but why? The point: when Chrysler bought out AMC I personally witnessed the engineering transition during the late 1980s, early 1990s. Every little glitch that AMC couldn't afford to, or didn't, deal with - Chrysler reengineered and fixed. Improvements were impressive, to say the least. Big ones, or little ones: as simple as a metal clip for the hood rod in place of a plastic one. There is NO comparison between the AMC legacy 1980s and the later models. Now I have a 97: steel rear door, all new electrical system, etc. A milestone evolution for the XJ. Mine is perfect, with only 88,000 miles - yet only market valued at maybe 6 grand in the USA. So, what I'm saying is that the later the year of the "old" model XJ you can get, the better. And they're not that expensive, all things considered. Before you drop that precious repair or upgrade $ into your late 1980s XJ - think twice. Maybe you can find an early/late 90s Chrysler-improved XJ, and for sure, your money will be better spent (at least in my opinion).

[tvisXJ]

I love my '87 but have had my fair share of problems here and there. Mainly because of the age/mileage of the rig

[ren]

Overall I prefer my AMC stuff, with only a couple of things that I think could/should have been done differently- like placing the M/C for the clutch right above the firewall connector for the ENTIRE wiring harness ( that was REALLY dumb) and using the stupid Puke o tranny. Oh, yeah- unit bearings instead of normal bearings for the front axle.
I like the RENIX system, since it seems to hop-up friendly, but some of those sensors cost a S*%^load.

[tvisXJ]

Ditto on all that. My MC made a mess all over down there.

[carnuck]

Blaming the car for the filter clogging? That's operator error of filling at that station! Breaking clutch pedals sounds pretty wild (and I'm rough on mine!) Are you sure yours isn't a VAM built rig? The VIN would start with a 1 if US built.
The extra wiring junk added to later models sucks when they break down. My '86 is still going strong (2.5L with TBI) at 600,000 miles. Motor is just ready for a rewind (got overheated badly last summer when some asshat punched the rad while it was parked on the street and my buddy didn't notice it till 5 miles later)
If you want a prissy car, then later models are okay. If you want an offroad rig, who wants to toss thou$and$ on a newer rig.

[Eagle]

I own several AMC vintage XJs and MJs, and two 2000 XJs. The new ones are nicer for "creature comforts," but for overalll quality and durability I think it's unlikely that either 2000 will ever match as far as my '88 XJ has gone, or last as long. The AMCs are simply sturdier vehicles. Chrysler changed a lot of things not to improve them but just to reduce the cost of building the vehicles. AMC's engineers had already done a very good job of optimizing the design. When you start cheapening an already-optimized design, you generally do not derive an increase in quality.

[outlander]

I wonder why the old renix motor usually out lasts the chrysler motor????

I would like to see what kind of shape your gen 2 xj is going to be in in about 17 years....mine is 17 years old and had about 170,000 miles on the ticker before I changed the motor due to a worn out timing chain,which was a result of neglect by the p.o.Its common knowledge that a properly maintained amc 4.0 can go 250-300,000 miles...maybe more.I've heard of more than one chrysler made 4.0 bitting the dust as early as 80,000 miles.

Take that as you will.....

[XJING]

323,000 miles, '88 XJ, Still running good. This thing has been lifted, used as a trail rig, brought back down to 2" to do part getter duty. Its been beat on well and the mantra always is with Renix: know the sensors and don't overheat!
I like the newer style and will pick one up soon, but the older ones are sturdy as there are still so many of them out there to prove it.

[luvme88xj]

88, 200,000+. No smoke, No puddles..."Flaots like a butterfly and stings like a bee".

[Ronbo]

I wonder why the old renix motor usually out lasts the chrysler motor????

I would like to see what kind of shape your gen 2 xj is going to be in in about 17 years....mine is 17 years old and had about 170,000 miles on the ticker before I changed the motor due to a worn out timing chain,which was a result of neglect by the p.o.Its common knowledge that a properly maintained amc 4.0 can go 250-300,000 miles...maybe more.I've heard of more than one chrysler made 4.0 bitting the dust as early as 80,000 miles.

Take that as you will.....

My "Chrysler" 4.0 hit that mileage in half the time your's did with zero problems.
I'm sure just as many low mileage Renix motors died, but that would have been quite some time ago, owners have moved on and long since stopped caring to comment about it.

$.02

[Oizarod115]

ive read alot of threads also where people have cooked their renix at 300+ degrees and had no warping or anything. pretty amazing... my only complaint would be the puegot...WHAT were they thinking.

[Rick Anderson]

OK, is not a RENIX engine just an AMC motor with Puegot Electronic Engine Management?

Is not the Chrysler era 2.5L and 4.0L motors, still AMC design, manufactured by Chrysler with Chrysler Electronic Engine Management?

Did Chrysler fire everyone at the AMC Engine Plant and moved engine building over to their plant?? Honestly, I don't know, but I doubt it.

Chrysler does set the specs and is resposible for quality during the motor assembly, as well, they have to taylor their Engine Management to the AMC motors. SO, you can argue that Chrysler dropped the ball, and the motors are less durable and quality than under AMC's management, BUT Chrysler at the same time was doing a great job with their other motors.

I've had Chrysler's 440 V8, 5.2L V8, 3.3L V6, 2.2L I4 and 2.0L I4. As well, I had a Chrysler/Mitsubushi 3.0L V6. All were great motors and got hundreds of thousands of miles out of each with little or no trouble. Some of them I put thru horrible abuse that they took and keep on running smoothly. With the exception of the headgasket on the 2.0L I4, which isn't a big deal for me, but can be for others, (a problem Chrysler has since solved BTW) all those motors have been great and are generally regarded by most as being good motors.

My complaint, and since I have a '95, its a Chrysler Era XJ; this is the first vehicle I've owned that at least half, if not more of the underside bolts are all siezed and snap off when trying to remove them. I've never had this much trouble with a vehicle, and its been mostly chrysler vehicles I've owned. Of all the vehicles I've owned, I had 1 shock bolt snap on a Mini-Van and I had the Axle U-Bolts snap on a '73 Charger, and thats it. My XJ has had more than half its underside bolts snap off.

Perhaps it was the prevous owner failure to do even the most basic cleaning of the vehicle, but judging from the posts here it seems common on the XJ's for the underside bolts to snap, WHY?

[Rick Anderson]

Anyone seen the new 2007 Dodge Nitro?
http://www.dodge.com/img/vehicleshowroom/nitro.jpg
http://www.dodge.com/en/nitro/index.html?context=vehiclePage&type=vehicleLink
Look Familiar?
It comes with a 4.0L 255HP V6 and Full Time 4X4 (Automatic Trans) and Part Time 4X4 (6spd Manual Trans).

How will it compare to a Jeep Liberty?

[89xj]

Blaming the car for the filter clogging? That's operator error of filling at that station! Breaking clutch pedals sounds pretty wild (and I'm rough on mine!) Are you sure yours isn't a VAM built rig? The VIN would start with a 1 if US built.
The extra wiring junk added to later models sucks when they break down. My '86 is still going strong (2.5L with TBI) at 600,000 miles. Motor is just ready for a rewind (got overheated badly last summer when some asshat punched the rad while it was parked on the street and my buddy didn't notice it till 5 miles later)
If you want a prissy car, then later models are okay. If you want an offroad rig, who wants to toss thou$and$ on a newer rig.

clutch pedal on my 89 broke off at the top. it was only held on with 2 tack welds.

i have 208k on mine without any major problems.

[midnightrunxj]

The way I compare a Renix to a later model is kinda like Sonny in the movie IRobot. "My creator made me with Better alloys". Thats why he can do things that other robots cant! If you get what im saying. Ive owned at least 5 of each(HO and Renix). Id have to say that te renix is my pick. I just like the way the motor feels and sounds much better.

[casm]

How will it compare to a Jeep Liberty?

For some reason I'd originally confused the Nitro (http://www.allpar.com/SUVs/dodge/nitro.html) with the upcoming Caliber (http://www.allpar.com/cars/dodge/caliber.html); the Caliber is going to spawn the Compass (http://www.allpar.com/model/jeep/compass.html), not the Nitro.

Anyway, I'd expect the Nitro to be about the same overall compared to a Liberty, though I'm willing to bet it won't get 'real' 4WD (i.e., a lockable centre diff and low range). Can't quite tell from the photos, but I'm wondering if it's going to have independent rear suspension - the specs say live axle rear, but things tend to change between spy shots and production...

[XJHummerRescue]

Driving an '89 Renix and both a '92 and '95 Chrysler HO Cherokees, I have to say, I love my '89. Not to say the HO motor doesnt last though, the '92 has 226k and still has all the power it needs. But my '89 with 155k is still breaking in :). Also, I have yet to have an underside bolt break on my 17 year old Jeep, and believe me, it is not clean under there... Oil, mud, and assorted other junk all over, as well as the mag chloride that CDOT sprays more than generously all over the streets here. Of course, Im not even going to think about touching the leaf shackle bolts unless im prepared to make custom lowered shackle mounts.

All in all, no matter what stupid thing I do to my '89, it still starts up and runs great, and thats all that matters to me :).

[otto]

OK, is not a RENIX engine just an AMC motor with Puegot Electronic Engine Management?
RENault/AMC---BendIX. My 1990 XJ, the last year of the RENIX control system, has many parts stamped with the Chysler Co. star, just as many others marked "AMC". It's a real mongrel, but like any good mutt smart and tough. I guess 1990 was more of a transition year. Very glad it came equipped with the AX-15 and not the BA-10 transmission:viking:

[XJHummerRescue]

Almost everything under the hood of my '89 says Chrysler Corp. on it... In fact I have yet to see anything that says AMC on it at all... ECU does say Bendix on it though :).

[rockwerks]

from a stand point of having many of both, the pre91 has less problems and from my experience better engine life

88 when sold had just under 200,000 now owners says around 300,000 no problems

my 87 mj has 235,000 and still within factory speecs and no issues

95 xj motor replaces at 165,000

96 xj motor spun bearing at 115,000

96 now has 98 motor with low miles on it and is starting to make the same noises as the 96 original motor just before it went kaput

as long as I can i will buy and run the renix junk

[rainer]

I have an 89 that has 150k miles on it that runs like crap. Tempermental as can be. Have a 95 that has 218k miles and runs like a dream. My 2000 has 95k miles on it and runs like the day it was purchased. All in all I prefer the later XJ's over the old Renix machines. I have had my share of both. I have owned nothing but XJ's over the last ten years or so. My 89 stumbles and lops at idle. it doesn't warm up properly. It's a real nightmare on the cold winter days.
Just my $.02 worth!

[CMNCHE]

clutch pedal on my 89 broke off at the top. it was only held on with 2 tack welds.

i have 208k on mine without any major problems.


Now that would suck in the middle of nowhere.

[rockwerks]

I have an 89 that has 150k miles on it that runs like crap. Tempermental as can be. Have a 95 that has 218k miles and runs like a dream. My 2000 has 95k miles on it and runs like the day it was purchased. All in all I prefer the later XJ's over the old Renix machines. I have had my share of both. I have owned nothing but XJ's over the last ten years or so. My 89 stumbles and lops at idle. it doesn't warm up properly. It's a real nightmare on the cold winter days.
Just my $.02 worth!

so some maintance...........get codes and fix stuff..........its amazing what a little effort to a 18 year old rig will do

[rainer]

If you can pull the codes on my 89 you're a better man than I.

[XJHummerRescue]

If you can pull the codes on my 89 you're a better man than I.

Sure can, just buy this http://cgi.ebay.com/ebaymotors/DRB-II-2-DIAGNOSTIC-SCAN-TOOL-CHRYSLER-DODGE-JEEP_W0QQitemZ4619214414QQcategoryZ43989QQssPageNa meZWDVWQQrdZ1QQcmdZViewItem and then get a hold of an adapter for '87-'90 Jeeps and you're set :)

[rockwerks]

Sure can, just buy this http://cgi.ebay.com/ebaymotors/DRB-II-2-DIAGNOSTIC-SCAN-TOOL-CHRYSLER-DODGE-JEEP_W0QQitemZ4619214414QQcategoryZ43989QQssPageNa meZWDVWQQrdZ1QQcmdZViewItem and then get a hold of an adapter for '87-'90 Jeeps and you're set :)

UMMMMMM.from what Ive read that will not scan the renix system.

but I take mine to the dealer and for a 25.00 fee they scan and give me the codes

[Rick Anderson]

Perhaps I'm biased, since I'm a long time Chrysler owner/fan before I ever got into Jeep.

I'm guessing Chrylser did not put in the effort to bring the AMC engines into the fold that they should have, and thus the AMC motors declined in durability and quality, compared to the other Chrysler motors.

The Chrysler Motors of that era and today easily are very fresh at 100k+ miles and last long past the 200k+ mile mark.

You fellas may know better than I, but how are the new Jeep Platforms doing? From what I hear they are nice, perhaps they are not "It's a Jeep Thing, You Wouldn't Understand", but I think its a case of Chrysler taking full ownership of the Jeep line, no more of re-using some of the bastard AMC motors, they are their motors and their technology, or at least what is used from AMC has been Chrysler's long enough, that they have integrated it.

[casm]

You fellas may know better than I, but how are the new Jeep Platforms doing?

If we're just talking about the '97-up XJs, I'm more than happy with my 2000 Limited which is currently just a few hundred miles shy of 100,000. Even my previous 2001 (totalled) which was at around 103,000 when it went swimming felt bulletproof. Between the two I've put somewhere in the region of 60K on them and both have good compression and no leaks at those mileages.

Having said that, as an exercise in comparison a friend of mine picked up an '89 Limited a few months ago with somewhere around 170,000 on the clock; it's now up around 180,000. Overall condition is comparable to mine as far as leaks and compression go, but we've been through a few items you'd expect to have go at those mileages - coolant bottle, water pump, valve cover gasket. Other than that, it's pulling strong and is probably slightly less than halfway through its usable life without major overhauling.

If we're talking about post-XJ Jeeps - well, I really don't have as much authority on them, but anecdotally the longer-term KJ owners I know have had no serious issues, but the WK people aren't as happy with theirs as the WJ owners. Seems to be a pattern with the Grands.

From what I hear they are nice, perhaps they are not "It's a Jeep Thing, You Wouldn't Understand", but I think its a case of Chrysler taking full ownership of the Jeep line, no more of re-using some of the bastard AMC motors, they are their motors and their technology, or at least what is used from AMC has been Chrysler's long enough, that they have integrated it.

My only real beef is that Chrysler dropped live-axle front suspension except for the Wranglers. Big mistake. They could've engineered a modular IFS for the 2WD KJs and WKs that would've been compatible with a slot-in live axle for the 4WD models.

[rainer]

Where I live none of the dealers have the equipment to scan the Renix System. The only one who had it was an old AMC Jeep dealer who no longer exists. The Chrysler dealers didn't see it fit to buy the Scan equipment so now we are on our own around here!

[Rick Anderson]

My only real beef is that Chrysler dropped live-axle front suspension except for the Wranglers. Big mistake. They could've engineered a modular IFS for the 2WD KJs and WKs that would've been compatible with a slot-in live axle for the 4WD models.
OK, I'm probably going to really show my 4WD Ignorance here, But why is IFS bad for 4WD? The HMVV's have 4 wheel independent suspension, as well, the new 7 ton Truck for the Military has 6 wheel independent suspension (pretty awesome suspension and drivetrain on that truck).

I would think Independent Suspension would give you more traction and control off road, than live axles.

Is it a case of strength and ruggitness? That most Independent Supsensions from the Major Manufacturers just don't have the strength or travel length for serous off-roading? Thus, the live axle is preferred, since they won't break and give you more flexibility and ability to modify, than the whimpy Independent suspensions you'd otherwise get from manufacturer?

I can see this being a reason to prefer a live axle over an independent suspension. Is it true that a properly designed independent suspension is better than a live axle in off roading? The modern military vehicles seem to indicate such is true.

[casm]

OK, I'm probably going to really show my 4WD Ignorance here, But why is IFS bad for 4WD?

IFS itself isn't inherently bad; how it's implemented can make it less desirable. More:

The HMVV's have 4 wheel independent suspension,

Correct, but look at how it's done on the Hummer - it's closer to a portal axle arrangement as opposed to A-arms (like on a KJ). This leaves less stuff under the truck to smash on obstacles. There are also articulation issues with IFS that don't crop up with live axles, as well as suspension and subframe ones that you start getting into with lifting.

as well, the new 7 ton Truck for the Military has 6 wheel independent suspension (pretty awesome suspension and drivetrain on that truck).

Don't know anything about this one - got a link?

I would think Independent Suspension would give you more traction and control off road, than live axles.

Based on vehicles I've owned, I far prefer a live axle than IFS for off-road work - and I'm basing this on two Series IIA Land-Rovers, Series I Range Rover, and two XJs vs. a Nissan Patrol, Lada Niva, and Subaru Brat, so there's a pretty wide spread of stuff in there. The last IFS 4x4 I drove was a current-model Nissan Frontier; while it felt great on the freeway, the IFS (as well as the traction/stability control stuff; that's a rant for another time) encouraged me to over-drive the truck's handling capabilities because it felt so car-like, and I just didn't care for how it operated off-road. Having said that, I've had some minor stick time in an H1 Alpha and came away very impressed with its capabilities, even if the thing was FREAKING HUGE.

Is it a case of strength and ruggitness? That most Independent Supsensions from the Major Manufacturers just don't have the strength or travel length for serous off-roading?

This is part of it, sure.

Thus, the live axle is preferred, since they won't break and give you more flexibility and ability to modify, than the whimpy Independent suspensions you'd otherwise get from manufacturer?

A good independent setup will outperform a poor-to-mediocre live axle setup. The problem with the IFS (IMHO) used on most 4x4s on the market today is that the basic designs tend to be derived from designs used on passenger cars; take a look at the current Land-Rover Discovery for a depressing example of this. Independent suspension can work very successfully for off-road use, but not when it robs clearance and articulation.

[GreenXJ2K]

http://detr6oit.50megs.com/ifs1.html
http://www.billhughes.com/XJversusKJ.jpg

seems pretty clear

[87manche]

in defense of IFS in those pictures it seems that the live axle setups were both more heavily modified. The KJ seems to have the swaybard still coneected, and that XJ is nasty looking, compared to what looks to be a mostly stock KJ.

[GreenXJ2K]

"in defense of IFS in those pictures it seems that the live axle setups were both more heavily modified. The KJ seems to have the swaybard still coneected, and that XJ is nasty looking, compared to what looks to be a mostly stock KJ."


Fully agree, maybe it wasnt the best representation, but nonetheless it does show the advantages of solid axles vs IFS especially in the rough stuff. IFS does offer more stability if your off roading at high speeds. (ie Jeepspeed type off roading)

john

[87manche]

"in defense of IFS in those pictures it seems that the live axle setups were both more heavily modified. The KJ seems to have the swaybard still coneected, and that XJ is nasty looking, compared to what looks to be a mostly stock KJ."


Fully agree, maybe it wasnt the best representation, but nonetheless it does show the advantages of solid axles vs IFS especially in the rough stuff. IFS does offer more stability if your off roading at high speeds. (ie Jeepspeed type off roading)

john
Agreed, that's why prerunning trucks almost all have IFS . I like the simplicity of live axles, solid axle shafts and no CV joints to explode or bind at severe angles.
I've seen some IFS trucks that were pretty capable though.

[Rick Anderson]

I have to agree with GreenXJ2K, those pics looked a little rigged in favor of the live axle setups.

BUT, those pictures do make something apperant to me. Those live axle trucks were getting that articulation with probably only a couple of hundreds of dollars of modifications to their rigs. The IFS vehicles looked like they could only achieve the same by throwing away the existing IFS and fabricating an entire new one, with body and drivetrain modifications to mount it, probably costing thousands of dollars.

I'm getting the picture, Thanks CASM, I agree, nothing inheritently wrong with IFS, just the IFS on available vehicles does not lend itself to serous off roading while the live axle setups can be easily modified for off-roading much easier.

Oh the 7 ton truck, the 7-Ton Medium Tactical Vehicle Replacement (MTVR) is made by Oshkosh Trucks.
http://www.globalsecurity.org/military/systems/ground/images/mtvr-truckshoot01.jpg
http://www.globalsecurity.org/military/systems/ground/mtvr-pics.htm
http://www.oshkoshtruck.com/pdf/Oshkosh_MTVR_brochure.pdf
With the Oshkosh TAK- 4™ Independent Suspension System, the MTVR achieves levels of perf o rmance never before realized in a tactical wheeled vehicle, enabling the MTVR to traverse terrain previously re g a rded as impassible by military trucks.
http://www.defenseworld.net/images/features/Combat%20Trucks/combat1.jpg
I haven't found any pics of the suspension, I'll have to continue to look, but I've seen it in person and from a muscle car guy, I have to tell you, its pretty impressive setup for the suspension and drivetrain.

[Jim D.]

Great thread evolution; pleased that so many folks take the time to contribute. As for me, personally, I still like my '97 better than the '87. But, I'm prepared to attribute that to mostly roading it, and to 10 years of perfecting and evolution applied to what was really special from day one.