someone school me on WJ's - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WJ Grand Cherokee Forum > someone school me on WJ's

RIGID LED Light Blowout Sale - All Sizes, All Series, all Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineJeep Wrangler Bushwacker Flat Fender Flare Sale at Baselin

Reply
Unread 11-14-2010, 12:10 PM   #1
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
someone school me on WJ's

I'm currently in the market for an XJ, but I'm seeing a lot of WJ's for sale. I used to drive a 4.0 2wd WJ for work, so I know it's comfortable. BUT how do the 4x4's do off-road? What axles can be had? D30 front, D44a rear? CV front axle shafts too weak? D44a needs too much work to make it just ok? What's up with Vari-Lock axles, and are they only found in certain packages? I'd like a V8, but the 4.0 is such a good motor, would I regret going to the 4.7? I'm not new to jeeps, and certainly not new to modding a rig for off-road duty, but I'd like this one to be more street/trail and easier for the family trips. I was planning on only 33's for the XJ, not sure about lifts and issues with lifts for the WJ. Any particular things to watch-out for while looking? I want this for moderate to difficult trails, some rocks, plan on 33's maybe 32's, lockers front & rear, but I don't want to break the bank or waste my weekends fixin it up, I would like something more out-of-the-box ready, I don't mind swapping axle shafts and what not, just tired of doing major component replacements - I swapped axles on 2 of my last 4 4x4's. Just like to do a lift/tires and run it. Is the WJ for me? Any info is greatly appreciated

__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 01:16 PM   #2
jgclorado
Registered User
 
Join Date: Jul 2008
Location: manitoba canada
Posts: 50
Thumbs up

WJ's make great street/trail rigs, but do have their share of common problems and weaknesses. Lifts are readily available but do tend to cost a little more than the XJ's probably due to lower demand. I6 vs V8? Probably more of a personal prefrance. I personaly like the I6 for its proven platform and ease of maintanence though fuel consumption is atroscious for the 4 litres of garden tractor like performance it produces. The possabilities are endless if the budget is unlimited but like any rig if your going to wheel it your going to break it. Front C.V axles, and front C.V driveshaft failures do seem to be common but are easy fixes with little money. Do be on the lookout for any heater core/ blend door issues though as it requires the entire dash to be removed. Push every button and flip every switch on the interior and make sure they work. Door locks and window regulators seem to fail too. Another point to be aware of is the electric fan if so equipt. Fan motors and relays are poor but are backed up by a conventional belt driven clutch type in most cases. Cant tell you much about diff options and T cases but im sure if you do a search you will find threads on all types.
jgclorado is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 02:19 PM   #3
billzcat1
Chicken in a Turkey Suit
2003 WJ 
 
Join Date: Oct 2008
Location: Redmond, WA
Posts: 8,537
First of all: WJJeeps.com - Jeep Grand Cherokee WJ 1999-2004 - great resource: hours of reading.

The WJs can be made very capable off-road as fundmentally they are nearly the same as every other Jeep...same axles, transfer case, steering, suspension, etc.

Up front you get a Dana 30 in all models and out back you get a Dana 35 with the I6 and the Dana 44A with the V8. SelectTrac 4WD gives you the same NV242 transfer case as you would get in an XJ. This is the preferred TC for off-road use, but the alternative (NV247) is not bad either...it just gives you fewer options and no fully-locked high-range mode. The NV247 came with QuadraTracII and QuadraDrive 4WD systems, the difference being the QT2 has open diffs front/rear and the QD has VariLok diffs front/rear. The Varilok diff works just like the NV247 transfer case - a gerotor-driven hydraulically-actuated clutch pack. As one wheel slips, it generates pressure and progressively locks the clutches and transfers torque side to side. Variloks work pretty well up to around a 32" tire. After that, the clutches in them are not able to transfer torque as well.

The V8 model is usually preferred in here...most debates about one over the other bring up points like the 545RFE transmission and D44a axle you get with the V8 which are much more robust than the 42RE and D35 combo. Also, the fuel mileage is similar between the two (sometimes people report BETTER with the V8) and the V8 has proven to be a reliable motor. Both motors have their own specific issues...just be sure to keep up on fluid changes as needed and use synthetic in the V8 to avoid sludging.

The Laredo models usually have fewer options, cloth seats, plastic/unpainted body cladding, and SelecTrac. They can be had with an I6 or a V8, but the V8s are rare. Leather is an option, as are painted bumpers. This is probably the best place to start for a wheeling rig.

The Limited models usually have most of options as standard equipment, have leather, have either QT2 or QD, and (at least in my area) are usually v8s. There's a V8 High Output option as well (270hp).

The Overland has pretty much every option as standard equipment, the 4.7HO standard, QuadraDrive standard, skid plates/tow hooks standard, and may have UpCountry suspension with a 20mm lift. This is also a good place to start and by swapping in the NV242 transfer case you get what we call "SelecDrive" giving you the best axles AND best transfer case. I went this route because of all the goodies you get right out-of-the-box plus the fact that I'm staying pretty mild with mine.

Blend Door issues are a failure in the HVAC system giving you only cold air. They can be fixed the hard and expensive way (remove whole dash) or by cutting the HVAC box behind the glovebox area and replacing just the broken components. It used to be the "ghetto" way to fix it to some, but it is very easy, very inexpensive, and Mopar even offers a kit now to do it this way. There are also aftermarket fixes that are a little higher quality and a little higher price. People always bring this up as a reason to avoid the WJ, or to avoid the Limited/Overland models, but it's really not a big deal anymore...just a little inconvenient when it goes.

One thing I think will turn you off to the WJs is there's a bit less aftermarket support than for the XJ and components overall are more expensive. The wheel wells are pretty small so it takes a lot of lift and trimming to run even 32s. While I know some people will disagree, I think the WJ is not intended for the very difficult trails...like anything else, you can build it for that, but building it for moderate trails is about 20 times easier. Axle swaps aren't as easy due to the somewhat different rear suspension (upper A-arm) and steering linkage (which I hear is more similar to the JK than the ubiquitous XJ/ZJ/TJ/MJ/LJ steering). For a street/moderate trail rig though, I think it's hard to do any better than a WJ V8.
billzcat1 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 03:42 PM   #4
charger
Registered User
2001 WJ 
 
Join Date: Sep 2008
Location: Staffordshire
Posts: 164
I have the I6 & came with rear 44a as stock
__________________
2001 WJ 4.0 I6 Powerflow Exhaust General Grabber AT2's 2" Lift 30mm Spacers.
charger is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 07:30 PM   #5
straty1987
Registered User
 
Join Date: Aug 2008
Posts: 2,522
i have a 02 limited with teh 4.7 V8
dana 30 front
dana 44a rear
and 247 TC with quad drive and quad trac 2

i went off roading with it stock a month back and had no problem, but did have help with a spotter on the stumps and rocks.

the V8 is a good motor if taken care of like most and will give you power when you need it. if you test drive one will you will fell the difference form the I6 in a wj.

a 4" lift and 33' sounds like what your wj would need,
straty1987 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 10:06 PM   #6
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
lots of good info guys, thanks. I'm definitely going to give the WJ's a look. anything I should steer away from? I noticed the blend door issue is only on limiteds because of the auto climate control, but looks like it's easily fixed so that doesn't bother me. what I wish I new more about was the vari-lok axles, anyone have an exploded diagram of how it works, and the components involved? can the vari-lok axles be upgraded with lockers? can the cv front axle shafts be swapped out for another jeeps stock u-jointed shafts? I know the xj motors had overheating issues, the zj v8's had plenum problems, what about the 4.7's, anything I should look for when testing the vehicle? sorry about all the questions, thanks for all the answers...
__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 10:34 PM   #7
esoxhntr
Registered User
2008 WK 
 
Join Date: Jun 2006
Location: Grand Valley, Ontario
Posts: 111
having owned both an xj and wj my advice, in (overly?) simplistic terms, is this:

if you are looking for a trail rig that you can pack your family into, get an xj.

if you are looking for a rig to pack your family into and go on trails, get a wj.

they're both jeeps and both capable.

xj's have much more aftermarket support, you have many more options and i would say if you're looking to run 33in tires, you would likely be able to do so more easily. that is not to say that a wj cannot be built into a serious off road machine though.
__________________
'97 XJ. 4.0. *sold*
'01 WJ. 4.7. *sold*
'08 WK 3.0 CRD. Camping, Towing, Fishing Machine v3.0
esoxhntr is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 10:51 PM   #8
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
Quote:
Originally Posted by esoxhntr View Post
having owned both an xj and wj my advice, in (overly?) simplistic terms, is this:

if you are looking for a trail rig that you can pack your family into, get an xj.

if you are looking for a rig to pack your family into and go on trails, get a wj.

they're both jeeps and both capable.

xj's have much more aftermarket support, you have many more options and i would say if you're looking to run 33in tires, you would likely be able to do so more easily. that is not to say that a wj cannot be built into a serious off road machine though.
haha, that's actually some good advice...I had a 00 TJ on 35's that was awesome on trail, but not so good driving to and from the trail, and the family didn't fit. my last rig was an 81 K5 Blazer on 37's which actually did good on the road, just horrible gas mileage and too big for a lot of the trails I took it on (but performed great and surprised a lot of jeepers) and I could fit the family, the dog, all the gear, extra parts, etc. with my kids getting older, I think I'm going for something more street friendly - but not ready to do the trailer queen set-up just yet. I've only seen 1 WJ on the trail and it performed ok, the aftermarket isn't too much of an issue for me, old blazers didn't have too much either, I usually made or had stuff fabbed for it. I don't know...I think I'm leaning more towards the WJ now than the XJ
__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 10:57 PM   #9
billzcat1
Chicken in a Turkey Suit
2003 WJ 
 
Join Date: Oct 2008
Location: Redmond, WA
Posts: 8,537
Quote:
Originally Posted by bigV View Post
. anything I should steer away from?
I would steer away from QuadraTracII because it has the less-desirable NV247 transfer case without the VariLok axles. It's not a bad system, but if you get open diffs, you might as well get the better transfer case with them, know what I mean?

Quote:
what I wish I new more about was the vari-lok axles, anyone have an exploded diagram of how it works, and the components involved?


There is a gerotor which supplies hydraulic pressure when there is a difference in axle speeds. You can Wiki "gerotor" to see how it works (pretty cool IMO). This hydraulic pressure then forces the clutch pack together, progressively locking the diff. The more slip, the more pressure, and the more it compresses the clutch pack.

Quote:
can the vari-lok axles be upgraded with lockers?
No. The lockers do not fit in the VariLok carrier. However, one could install an open carrier and axles into the diff housing, but by then all you are using from the VariLok is the housing itself. Best to start with open diffs.

Quote:
can the cv front axle shafts be swapped out for another jeeps stock u-jointed shafts?
Not exactly. Later models had U-joint shafts, and you can also upgrade the shaft and yokes through aftermarket companies. But for just a simple swap-something-in-real-quick-like option, there isn't much. You just can't get away from changing the whole driveshaft and yokes.

Quote:
I know the xj motors had overheating issues, the zj v8's had plenum problems, what about the 4.7's
Timing covers have occasional failures in the water jacket. This may be due to a faulty casting/production run, may be due to running the wrong coolant, may be due to coolant contamination, and overall, seems fairly infrequent. Also, if overheated, heads can warp (typical of ANY motor with aluminum heads/cast iron block) and valve seats can drop. The valve seat issue is not common, but does happen. I think I see 20 cracked I6 pistons for every valve seat dropped in this forum. There are issues with oil sludging, but changing the PCV valve is a 60,000 mile recommended service and I bet those with sludge did not change the valve as required. Also, running good oil with proper OCIs will help that.

Neither engine is really "problematic". Both are reliable and both can last 200k+ with moderate care. Can't go wrong either way.
billzcat1 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:07 PM   #10
esoxhntr
Registered User
2008 WK 
 
Join Date: Jun 2006
Location: Grand Valley, Ontario
Posts: 111
sounds like a wj may be for you then.

i would not go back to the xj now that i have the wj. but, i don't do any hard core wheeling. I enjoy the smoothness of the v8 on the hwy, it pulls the boat nicely and i can cram more stuff in it. not to mention, i am getting old - having my butt warmed by the seat warmers while i drive into a buddy's hunt camp in november is nice.
__________________
'97 XJ. 4.0. *sold*
'01 WJ. 4.7. *sold*
'08 WK 3.0 CRD. Camping, Towing, Fishing Machine v3.0
esoxhntr is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:14 PM   #11
billzcat1
Chicken in a Turkey Suit
2003 WJ 
 
Join Date: Oct 2008
Location: Redmond, WA
Posts: 8,537
Some other material on the function of VariLok (aka "GeroDisc")



Quote:
I posted a comment last week about the 1999 Jeep Grand Cherokee
"Quadra-Trac" and how it uses a newer technology in limited slip
differentials called GeroDisc. Basically it is a set of clutches with a
gerotor pump that senses slip on an axle and then increases pressure in
the clutches to improve torque distribution. I promised a writeup on
GeroDisc to a few people so here it is, the following is an excerpt from
some literature they sent me a year or so ago:
----------------------------
WHAT IS GERODISC?
GERODISC is a hydro-mechanical limited slip and coupling device
incorporating a hydraulic pump section, a piston, and a clutch pack. It
has been designed as a "clean sheet" approach not tied to a prior
technology nor to a dedicated manufacturing process.

HOW DOES IT WORK?
ASHA's GERODISC limited slip differential/coupling is sensitive to, and
controls the delta rpm between the right and left wheels of a drive axle
and/or the front and rear axles of an All Wheel Drive or 4 wheel drive
vehicle.
In straight line motion, the drive wheels turn at the same speed with no
resultant GERODISC pump action. When a low delta speed occurs between
the drive wheels, such as negotiating a curve or parking maneuver, the
pump develops some nominal pressure and oil volume which is discharged
through an orifice created for this purpose.
When a predetermined higher delta rpm is encountered, such as occures
with a loss of traction at one wheel, the pump then operates at a rate
higher than the orifice is tuned to discharge. A simultaneous hydraulic
pressure is developed, which is subsequently applied to a piston and
associated clutch assembly, resulting in a very precisely controlled
transfer of torque. The torque transfer engagement occurs within 1/7 of
a revolution when the predetermined delta rpm is reached.
GERODISC does not lock up. As soon as GERODISC causes the delta rpm
between the two wheels to become more synchronous, pump pressure is
commensurately reduced to a point where the friction elements assume a
passive mode. Instead of jerking, or a harsh transitional engagement,
wheel spin is slowed and eliminated with a very powerful, fluid action.
GERODISC's hydraulic damping reduces the tendency to hunt between engage
and disengage modes.
Quote:
Jan. 27, 1999--ASHA Corporation (Nasdaq:ASHA) is pleased to congratulate its Tier I GERODISC(TM) licensees and the DaimlerChrysler Jeep Corporation for the industry-wide recognition of the 1999 Jeep Grand Cherokee Quadra-Trac II(R) transfer case and Quadra-Drive(TM) full-time four-wheel drive system.

"These awards being received by our clients for systems they have developed utilizing GERODISC(TM) technology are some of the most prestigious awards in the automotive industry, representing consumer and automotive trade publications, as well as our industry peers. Each of us at ASHA are honored," said Jack McCormack, ASHA Chairman and CEO.

The seven national automotive awards include being named as a finalist for the prestigious Automotive News / Ernst & Young LLP PACE(TM) Award for excellence in innovation among automotive suppliers. The 1999 PACE(TM) Awards are selected by an independent panel of distinguished judges consisting of industry, academic, and business leaders. A record setting 89 companies were considered.

The 1999 Jeep Grand Cherokee Quadra-Drive(TM) four-wheel drive system was singled out as "Technology of the Year" by Automobile Magazine. The award sites the GERODISC(TM) hydraulic pump developed by ASHA as being at the heart of the system. ASHA has licensed the patented GERODISC(TM) coupling technology to New Venture Gear, a Tier I supplier for its innovative new Progressive Transfer Case(TM) utilized in the 1999 Jeep Grand Cherokee.

In January, the North American North American International Auto Show in Detroit, Michigan named the Jeep Grand Cherokee the 1999 "North American Truck of the Year". Christopher Jensen said, "The 1999 Jeep Grand Cherokee sets the new standard among sport utilities for the magical mixture of pavement prowess with an undiluted ability to handle hardcore, off-road challenges."

Automotive Engineering Magazine selects Steyr's Geromatic(R) traction system as a top automotive product for 1998. AE referred to it as one of the "The Best of the Best" selected from more than one thousand candidates. ASHA Corporation's multiple license agreements with Steyr include the production of transaxles, all-wheel drive couplings, rear axles, and twin-disc rear axles.

Popular Science Magazine's 11th Annual "Best of What's New" Awards singles out the 1999 Jeep Grand Cherokee and its Quadra-Drive(TM) four-wheel drive system. The Popular Science editors went on to congratulate this outstanding achievement in creating a new generation sport utility vehicle.

The American Automobile Association{ has given its "Top Car" Award to the 1999 Jeep Grand Cherokee as the best sport utility vehicle priced over $25,000. The evaluation will be published in the 1999 AAA Autograph(R) Book...an annual evaluation of new vehicles.

Petersen Publishing names the 1999 Jeep Grand Cherokee 4-Wheel & Off-Road Magazine's "4x4 of the Year". "The all-new Jeep Grand Cherokee rose above some extremely tough competition," said Cole Quinnell, 4-Wheel & Off-Road editor. "Whether it is on-road performance and handling, or capability in treacherous off-road terrain, the 1999 Jeep Grand Cherokee masters it all. We were very impressed how this vehicle combines a true car-like on-road feel with the off-road capability of every Jeep vehicle. The Grand Cherokee is still king of the hill."

ASHA Corporation develops advanced technology products and automotive design and manufacturing techniques for the global automotive industry, and licenses the award winning GERODISC(TM) traction control system. Currently, ASHA has twenty worldwide license agreements in place for 4WD, 2WD, and AWD platforms. On January 8, 1999, ASHA acquired McLaren Engines, Inc., a complete powertrain design, fabricating, and testing facility occupying over 55,000 square feet of office and laboratory space. During its thirty year record of service, McLaren Engines has serviced the research, development, and testing needs of more than one hundred clients.
billzcat1 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:23 PM   #12
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
Quote:
Originally Posted by billzcat1 View Post
No. The lockers do not fit in the VariLok carrier. However, one could install an open carrier and axles into the diff housing, but by then all you are using from the VariLok is the housing itself. Best to start with open diffs.
so the axle shafts themselves are specific to the vari-lok carrier? is there a bias ratio on these? can the clutch packs be rebuilt? so I might be more interested in the QT2 or selectrac if I want lockers. does the QT2 and QD have a low lock feature?
__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:30 PM   #13
billzcat1
Chicken in a Turkey Suit
2003 WJ 
 
Join Date: Oct 2008
Location: Redmond, WA
Posts: 8,537
Yes, the axle shafts are specific to VariLok - different lengths for that carrier. No bias ratio as it is progressively locked by hydraulic pressure, not by centrifugal force, torque-loaded gears, or springs. The clutch packs aren't available as separate parts. Since the plates are not under pressure like in a Trac-Loc and only engage when wheel slip occurs, they last a very very very long time.

More info:
How does Gerodisc work, do the clutch plates last?

QT2 does have locking in 4LO, but my vote is skip it in favor of SelecTrac. If you are going hardcore enough to need lockers over VariLoks, then you need an NV242 over an NV247 for sure.
billzcat1 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:44 PM   #14
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
gotch...progressive...that's a crazy pic in that link seeing as I'm gonna be spendin a little more $$ on the WJ than I was planning on the XJ, maybe the vari-loks will be better than nothing now. as for the 247 t-case, is it weaker than the 242 or is it just the fact that the 242 can go into 2wd mode that makes it more desirable?

thanks again for all the info
__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Unread 11-14-2010, 11:46 PM   #15
bigV
Registered User
1991 YJ Wrangler 
 
Join Date: Oct 2006
Location: , SoCal
Posts: 1,561
Quote:
Originally Posted by billzcat1 View Post
QT2 does have locking in 4LO
and the quadra drive 247? or are they the same cases just the vari-lok axles make it "drive"
__________________
www.hd4w.org
High Desert 4 Wheelers
bigV is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.