anyone?

 

Coolasice and Captain Hook

you guys around?

did you see my previouce post about the things i did and reported back with?

do you think i need a schematic or something of how the RF Actuator works that engages the CV axle?

The 4 wheel drive lights are functioning correctly even when i have the manifold line CAPPED and the Check Valve completely disconnected
(they flash for a split second when i press one of the 3 buttons and then it goes to steady on) so the 4 wheel drive system does appear to be functioning but the RF axle is still not engaging because if i have the RF tire off the ground i can freely spin the tire and does make a "clicking" if i try 4lo or 4hi but in 2hi it dont do this.
i havent checked that same tire with the vacuum line completely disconnected

and i still here the noise behind the dash somewhere even when check valve is completely removed and the manifold line is capped or uncapped
it dont matter

i think im gonna jack up the LF and RF tires and rotate both while in 4lo and 4hi
from what i understand the LF tire is always engaged (in any mode...2hi, 4hi or 4lo) is this true?

 

ok here is some more (new) data.

both front tires OFF the ground with jack stands
both rear tires ON on ground
transmission = PARK
Vacuum lines ALL connected

(3 button) 4 wheel drive:
2hi:
spin either front tire freely
front diff drive shaft dont move at all
no clicking from either tire if i rotate either tire in same direction

4hi:
if i rock (either) tire back and fourth i can see front diff drive shaft move a little
if i keep spinning either front tire in the same direction the drive shaft will not move any more
drive shaft only moves when i rock either tire back and fourth and it only moves a little
if i keep rotating either front tire in same direction i hear clicking

hope this helps

just wanted to add:
it does this in Park, Nuetral and Drive
when in Drive i have the engine shut off
i know this would normally disengage the RF CV axle but im looking at the LF and it still turns the same as in Park or Nuetral

 

1) Connect a vacuum gauge to the source line from the engine and start the engine. With the engine at idle, post the vacuum reading.

2) Disconnect the vacuum line from the axle actuator and put a vacuum gauge on the line. Make sure all other vacuum lines, and the check valve, are connected. With the engine at idle in park, select 4WD and post vacuum reading. Shut the engine off and take another reading after 5 minutes, and post the reading.

3) With the engine at idle in park, transfer case still in 4WD and the vacuum gauge still connected to the axle actuator line: Select 2WD, does the vacuum drop to zero immediately? If not, what is the vacuum reading in 2WD?

 

1
18 psi with only the manifold line going to the vacuum guage

2
are you telling me to disconnect the diaphram under the battery and hook vacuum up there?

im pretty sure its not the vacuum lines anymore
the noise under the dash isnt from a vacuum source as i disconnected the check valve completely and it still did it.
so it must not be vacuum

by me having the vehicles front tires off the ground and when i rotate the front tires while in 4hi each tires will make a clicking noise

it dont do this when im in 2hi
there is no noise

awaiting further instructions

 

Here a question that might seem off subject.. Do your vent controls work on your heater? Defrost to vent to floor?

 

Reason I ask is because on my 99 I had the heater core replaced.. Vent controls stopped working after that.. Took it back into him and he forgot to connect a vacuum line on the drivers side floor under the console I think.. That could be the hissing sound you hear on the inside.. That might also cause a large enough vacuum leak for the diaphragm not to fully engage. How far back is the diaphragm pulling in? The face of it should be almost flush with the housing. I just had to fix my daughters 4wd yesterday.

 

No problem there, good vacuum. This gives us a "benchmark" of what the vacuum should be at various places in the systems.

Yes.

I agree, unless for some unknown reason, someone ran a separate vacuum line for the HVAC, which is doubtful.

I understand, and step #2 will tell us if the actuator is getting sufficient vacuum, and holding it. If it doesn't show 18" of vacuum, and or doesn't hold, we know there's a problem in the vacuum system somewhere. If the vacuum checks OK, we know the problem is either the actuator isn't pulling in far enough, or there's a problem with the clutch in the axle.

 

Not sure if the 99 and 01 both have the vacuum solenoid on the firewall or not.. The firewall mounted solenoid will bleed air out when vehicle is off. This IS normal..

 

Ahhh, good call! You're right! 1999 is equipped with the solenoid.