4wd is out on my 99 grand cherokee with select trac runs in 2wd can i just take out the drive shaft for the 4 wheel drive

are you on pavement, or offroad.?
99 Cherokee what transfer case?
if Part time system. then,.
are your tires on ice or dirt?
if not its cockpit error.
read the operators guide, on this.
if on ICE,say so, we can not know what transfer case you have
nor what tires are sitting on.
do tell, and we can tell you what good or bad.

here is the build list for these years XJ
what do you have. ?
The full time box, must not be in 4Lo , on pavement
unless it too is on ice .

All the transfer cases used on the Cherokee were chain driven with aluminium housings. Command-Trac was standard on XJ models built with 4WD.

• 1984-1987: New Process NP207 Command-Trac, part-time only, 2.61:1 ratio with low range
• 1984-1986: New Process NP228/229 Selec-Trac, full- or part-time, 2.61:1 ratio with low range

NP228/229 has a vacuum switch for 2WD-4WD selection on the fly and a separate manual lever for low range

• 1987-2001: New Process NP231 Command-Trac, part-time only, 2.72:1 ratio with low range

NP231 has the following settings: 2HI, 4HI, N, 4LO

• 1987-2001: New Process NP242 Selec-Trac, full-time or part-time, 2.72:1 ratio with low range

NP242 has the following settings: 2HI, 4 full-time, 4 part-time, N, 4LO

-----------------------------------
never post questions on 4wd unless you know what is there.
the transfer case, also has tag , telling what it is.

Hello guy
try posting what 4wd system you have,? first.
command trac or select track, (the latter is full time)
part time or the full time system,
we cant guess it....
read the operators guide first, if a part time system only
as i suspect, stop driving on dry pavement.
it's only for ice, or dirt. part time. part time is not a full time system.
Command-Trac
shifting to 4wd on dry (means no ice) pavement causes, drive line wind up! and the gears to lockup. (see steering get tight in turns?> and is dangerous to drive it like this , you, me and the box)
posted here 100s of times.

http://www.rubicon-trail.com/4WD101/driveline-bind.html


the non grand Cherokee. early

had these choices

• 1987-2001: New Process NP231 Command-Trac, part-time only, 2.72:1 ratio with low range

NP231 has the following settings: 2HI, 4HI, N, 4LO

• 1987-2001: New Process NP242 Selec-Trac, full-time or part-time, 2.72:1 ratio with low range

NP242 has the following settings: 2HI, 4 full-time, 4 part-time, N, 4LO


as you can see you need to first know, what NP box you have or
photo your shift lever for 4wd, an post it and we tell you.

more facts, on select trac. (totally unlike command trac)
Selec-Trac locking hub is used on 4WD Cherokee. Selec-Trac
utilizes a non-disconnect front axle. Engagement of 2WD or 4WD is
accomplished at transfer case by means of mechanical shift linkage.
System allows full or part time 4WD. Selec-Trac can be shifted into
2WD or 4WD modes from inside the vehicle at any speed.
unquote
next from the service manual,
4WD TO 2WD
1) Place mode select switch in 2WD position. Transfer case
should shift to 2WD and not allow shifting into 4WD or LO range. Axle
should shift after transfer case shifts.
2) To determine if front axle has completed a shift out of
4WD into 2WD, position mode select switch back to 4WD position while
operating vehicle at slow speed. If vehicle shifts into 2WD, axle will
ratchet. If shift is not completed, transfer case will shift into 4WD
and hissing sound will come from mode select switch.
end quote.

if unsure read the FSM book its free.
shows you both systems and how to diagnose it.

in the box, click Cherokee,,then click 1993, and behold.
the real deal.

http://www.morris4x4center.com/knowledge-base/index.htm?utm_source=cj#service

which system?
we cant guess what is In YOUR CAR, ever.
you must SAY. or RTM, in the glove box.
and why are you using 4wd on dry pavement, now>?


4WD: Select-Trac (or older Select-Drive has a slip coupling too, NP129/229) is AWD in that, "the "4Hi" setting the drive shafts were coupled together using a viscous-type coupler " this anti wind up slipper"
Watch out for exception 1: Select-Trac NP228 based jeeps, it does not have a viscous-type limited-slip coupling. It was used briefly in 1986.
Quada-Trac is full time 4WD (not in lock mode) has a real center differential to shift torque between front and rear. This is the best system , not just a slip clutch as above. Then went BACK to the slipper in 1980. (odd huh?) Up to 1998.
Quadra-Trac-II "4-All Time", "N" or neutral, and "4-Lo". In "4-All Time", torque is applied to the rear wheels under normal driving conditions.
If the rear axle starts rotating at a significantly higher rate than the front axle, hydraulic pressure builds up in the gerotor oil pump and causes the clutch pack, to progressively transfer torque to the front axle, until both axles return to the same speed
Quadra-Trac I was introduced in 2004-10, same as above but is automatic with no driver controls ,like above.
The Quadra-Drive system was introduced in 1999 and is based on the Quadra-Trac II system but adds limited slip differentials (the best full time system ,with great traction to all wheels all the time) 1999 to 04.
Quadra-Drive-II has electronic limited slip differentials or ELSDs 2005 up.

what does won't mean?

1. The lamp don't come on. (the lamp can be out)
2. actual 4wd fails , that is, the tires don't turn, up front,under power, id bet you didnt check? actual 4wd actions?

which one.? which 4wd do you have.? and what mode did you select.?
http://en.wikipedia.org/wiki/Jeep_four-wheel-drive_systems

on Part time, you cant drive on dry pavement in PT 4WD.
got Part time? I think not, but??? dont know for sure....
Guessing:
i bet you have select track (no GRAND in title)
quote:
Selec-Trac offers full-time all wheel drive in addition to the part-time 4WD of Command-Trac. Full-Time all wheel drive has the ability for the front and rear axles to rotate at different speeds, making driving on dry and wet surfaces possible year-round without shifting back to 2WD again. It still has the ability to lock the front and rear axles.
end quote
-----------------------------------------------------------------------------------

do not use COMMAND-trac on dry pavement. its for ice or offroad only.

I think im having the same problem. I just bought a 2000 grand laredo selec trac 100,000 miles,in full time4wd front drive shaft spins but jeep dont move in part time and lo 4wd it will move but still in 2wd?????? any answers

without changing transfer case it is not possible.* (normal circumstances)

what you need is NP242 or NP231 selectrac /command trac transfer cases from 4.0 G.cherokee or Cherokee. those allows you to select 2wd for all time driving and let you decide on mode when 4wd is needed.

also you can test to see how it feels by removing front shaft for trial purposes but you will be loosing power because all time transfer case distributes the traction over front and rear.( do not try this when driving in traffic)

*I also heard that it is possible to convert all time mode to all time 2wd but keeping 4wd low intact.( i wonder how realiable the result is though)

you need to have the front axles checked or replaced,they are not freely turning

sound like the box computer has gone

1st let me make sure I understand your Jeeps 4 wheel drive. I believe the quadra trac system is a full time 4 wheel drive, there is no 2 wheel drive setting, only a separate 4 Lo (for very slow speed). If this is correct, the problem is, the quadra trac system you have is supposed to compensate for any variations in wheel speed, whether it's driving in the snow, or cutting the wheels sharply to park on dry pavement. What u describe is typical behavior of a part time 4 wheel drive system. The problem is, your full time 4x4 should be compensating for this, and it's not. So, let me know if the above info about your 4wd is accurate (no part time 4wd setting, no 2wd setting, only full time 4wd and 4Lo setting. If it is, the system is not compensating for changes in the wheel slippage correctly.

Hi Terrell,

First off, thanks for the detailed description of your problem. I wish they were all as well written as yours.

It's tough not being able to hear the noise it's making. Luckily I can draw parallels to my own experiences with GC's. Mine has 'Select-Trac', which like your 'Command-Trac', enables us to shift on the fly to 4WD. Meaning, we don't have to stop, get out, lock the hubs, get back in then shift to 4WD. Also like yours, my front end was making some noise.

What was up with mine: The 'Select-Trac' on my G.C. is a lever type switch on the center console. When I switch from 2WD to 4WD it routes a vacuum line to an actuator which engages the transfer case. The moving parts are all near the T-Case. While in 4WD, going any faster than a crawl I'd hear a mild grinding/whirring sound. It increased with speed, all but disappeared as I decelerated and made me crazy.

What it turned out to be was a Vacuum leak. The 'bellows' (for lack of a better description) type actuator was only partially engaging the the 4WD. Enough to lock the drive train, not enough to fully mesh the gears resulting in all sorts of worrisome noises. I found and fixed the leak, adjusted the range on the mode rod and that was it.

You're thinking, 'That's special'.

Well here's the parallel.
Command-Trac is also vacuum actuated. The difference is it engages your hubs from the the front axle by means of a 'shift fork'. The technical name is the 'Command-Trac Axle Shift Motor'.
When applied, the vacuum actuator moves the fork one way or the other, engaging or disengaging the hubs.

From your excellent diagnosis, it sounds like 4WD isn't fully disengaging.
You were correct about the front drive shaft. It should not be spinning while in 2WD.

Qualifiers: Is the grinding sound different at low speeds? While making sharp turns?

Have another look with these new facts in mind. Check vacuum lines, lubricant in the axle.

If you get me your engine size, tranny type, etc. I can probably scare up some vacuum diagrams (on the off chance you need them).

I hope this opens new doors for you.
Comment me back with what you come up with.
Good luck buddy.
Mike