Transfer Case help

[mach1mustang351]

Okay team.  I have been digging for a while now and I give up.  Is there a good way to check if a transfer case is good while it is in the car?? The vehicle isn't running and I am preparing to remove the busted engine.  I am looking to test the case because I joust noticed there are mismatched tires on the car but it has also had been sittign a long time because of an exploded engine.  Any help appreciated.

[mudkicker715]

I had a write on that. and that sounds correct casper.

[priya]

The procedure for testing the vicious coupling in the car is as follows:

1) place the car on a level surface.  Stop engine
2) place transmission shift lever in neutral
3) raise one front wheel off floor
4) place torque wrench on any lugnut of wheel just raised.
5) rotate wheel using torque wrench and measure torque required to rotate wheel.
6) if coupling is operating properly it should require a minimum of 45 foot-pounds (61N*m) to rotate wheel.
7) if rotating torque is at or above specified limit you're good to go.

[mudkicker715]

mudkicker, if i can turn the front while holding the rear by HAND, and the oil is BLACK! dont smell like atf. (smells wierd actually) should i be worried about that vc??

(sorry im hijacking this thread, but this is about EXACTLY what i was going to ask.)

your vc ls definetly shot. the silicon oil goodness got tossed out. now its like an 86 model. unless someone stuffed who knows what in there at one time and it actually is good.

[carnuck]

The test is supposed to be in inch pounds, not foot pounds!

[priya]

The test is supposed to be in inch pounds, not foot pounds!

The technical service manual clearly says foot-pounds.

[Draekon]

Copied from my TSM:

In-Automobile Torque Bias Check
(1) Place automobile on level surface. Stop engine.
(2) Place transmission shift lever in Neutral.
(3) Raise one front wheel off floor.
(4) Remove hub cap from wheel just raised.
(5) Assemble socket and torque' wrench and install
on any lugnut of wheel just raised.
(6) Rotate wheel using torque wrench and measure
torque required to rotate wheel.
(7) If coupling is operating properly, it should re-,
quire minimum of 45 foot-pounds (61 N»m) to rotate
wheel.
(8 ) If rotating torque is at or above specified limit,
remove wrench, install hub cap and lower wheel.
(9) If rotating torque is below specified limit, remove
wrench, install hub cap, lower wheel and refer to

On-Bench Torque Bias Check.
NOTE: The following procedure can be used as both a
diagnostic procedure and a means of verifying coupling
operation prior to reassembly and installation of the
transfer case.
(1) Remove and disassemble transfer case as outlined
in this chapter.
(2) Install clutch gear on side gear.
(3) Install assembled clutch gear and side gear in
viscous coupling.
(4) Mount assembled coupling and gears in vise.
Place wood blocks between vise jaws and side gear and
clamp side gear firmly (fig.- 2D-2).
CAUTION: Wood blocks must be placed between the
vise jaws and side gear to avoid damaging the gear.
(5) Check engagement of clutch gear in viscous coupling.
Be sure gear Is fully engaged in coupling before
proceeding. If necessary, loosen vise and reposition wood
blocks so they support gear in coupling."
(6) Install rear' output shaft in viscous coupling (fig.
2D-2).
(7) Install yoke on rear output shaft and install
yoke retaining nut.
(8 ) Assemble and install socket and torque wrench
on yoke retaining nut (fig. 2D-2).
(9) Rotate rear output shaft using torque wrench
and measure torque required to rotate shaft in coupling.
(10) Torque - required to rotate shaft in coupling
should be minimum of 25 foot-pounds (34 N«m) torque.
(11) If rotating torque is less than specified, coupling
has malfunctioned. If torque is at or above specified
limit, coupling is in good condition.

[mach1mustang351]

Copied from my TSM:

In-Automobile Torque Bias Check
(1) Place automobile on level surface. Stop engine.
(2) Place transmission shift lever in Neutral.
(3) Raise one front wheel off floor.
(4) Remove hub cap from wheel just raised.
(5) Assemble socket and torque' wrench and install
on any lugnut of wheel just raised.
(6) Rotate wheel using torque wrench and measure
torque required to rotate wheel.
(7) If coupling is operating properly, it should re-,
quire minimum of 45 foot-pounds (61 N»m) to rotate
wheel.
(8 ) If rotating torque is at or above specified limit,
remove wrench, install hub cap and lower wheel.
(9) If rotating torque is below specified limit, remove
wrench, install hub cap, lower wheel and refer to

On-Bench Torque Bias Check.
NOTE: The following procedure can be used as both a
diagnostic procedure and a means of verifying coupling
operation prior to reassembly and installation of the
transfer case.
(1) Remove and disassemble transfer case as outlined
in this chapter.
(2) Install clutch gear on side gear.
(3) Install assembled clutch gear and side gear in
viscous coupling.
(4) Mount assembled coupling and gears in vise.
Place wood blocks between vise jaws and side gear and
clamp side gear firmly (fig.- 2D-2).
CAUTION: Wood blocks must be placed between the
vise jaws and side gear to avoid damaging the gear.
(5) Check engagement of clutch gear in viscous coupling.
Be sure gear Is fully engaged in coupling before
proceeding. If necessary, loosen vise and reposition wood
blocks so they support gear in coupling."
(6) Install rear' output shaft in viscous coupling (fig.
2D-2).
(7) Install yoke on rear output shaft and install
yoke retaining nut.
(8 ) Assemble and install socket and torque wrench
on yoke retaining nut (fig. 2D-2).
(9) Rotate rear output shaft using torque wrench
and measure torque required to rotate shaft in coupling.
(10) Torque - required to rotate shaft in coupling
should be minimum of 25 foot-pounds (34 N«m) torque.
(11) If rotating torque is less than specified, coupling
has malfunctioned. If torque is at or above specified
limit, coupling is in good condition.

Thank you.  I gave you an Egg for that.  When I get back home I'll try that one out. 

I only had one question and it could be because i't late and I'm tired and I shouldn't be thinking.  Does the vehicle have to be in 4wd for this to work?  In 2wd or engine not running wouldn't the "up" front wheel spin free anyway because of the axle dissconnect??

[eaglefreek]

I was going to comment to make sure you are in 4wd before I saw your last question. The TSM test must have been written for the AWD cars.

[priya]

Thank you.  I gave you an Egg for that.  When I get back home I'll try that one out. 

No thanks for me?  I also copied from the TSM.

[priya]

Casper, from what I've read the VC oil is the consistency of honey.  My understanding is that it is also the VC oil that goes bad and generally there is nothing wrong with the mechanical components of the VC.

[carnuck]

The VC loses it's oil and can't work after that. The oil destroys the bearings etc because it's basically liquid sand.

25 is a FAR cry from 75 (I know because I killed the VC in a NP229 doing the test at 75 ft lbs because I didn't read it right)

[mach1mustang351]

Well I read all this and of course I got all motivated and ripped out the front axle before I could check... oops.  I guess I'll find out when I get the fresh engine in.  I did find out I have the full time 4 wheel model.  I also learned I have 2.72 gears.  What a good day.

[jspeez13]

i am wondering the same thing about my np119.  i changed the fluid and i had think gray stuff dripping out of the case ater all the rest of the fluid came out.. is this the vc fluid.  i was reading on here that when the vc fails it acts like an open differential.  does that mean it still works more or less?  im a little confused on that. 

[carnuck]

Could be the VC started leaking but hasn't spit it all out yet.