4x4 Delay Time
#1
#2
It should be a lot less than that. They should lock up as soon as the transfer case engages into a 4WD mode, using a contact in the limit switches in the transfer case.
When you engage the transfer case, a solenoid in the case engages a clutch which gets the front components moving prior to engaging the chain to the rear output shaft. This is what allows "shift on the fly" -- it's a solenoid activated "synchro" if you will.
As soon as the control shaft is rotated by the motor to a point where the chain is engaged, then the hubs should come online. At least, that's the way I read the logic.
If your transfer case is very slow, that may be another matter, or if you have a problem with the actuating mechanism for the hubs that could be a problem also.
What year is your truck, by the way?
When you engage the transfer case, a solenoid in the case engages a clutch which gets the front components moving prior to engaging the chain to the rear output shaft. This is what allows "shift on the fly" -- it's a solenoid activated "synchro" if you will.
As soon as the control shaft is rotated by the motor to a point where the chain is engaged, then the hubs should come online. At least, that's the way I read the logic.
If your transfer case is very slow, that may be another matter, or if you have a problem with the actuating mechanism for the hubs that could be a problem also.
What year is your truck, by the way?
#3
#9
#11
#13
Originally Posted by Buck44
Does anyone know what the delay time should be for the hubs to lock? Someone told me from the time you turn the switch on the dash to the hubs actually engaging was about 50 seconds. This seems excessive to me.
See: Ranger PVH Diagnostics TSB
#14
Good reference, Joe -- but where does it confirm 50 second engagement times? I didn't see that. Is that just what people experience or is it a spec somewhere that you know of?
It still seems like an awful long time to me.
I did see a 15 second disengagement timer though.
Unless the vacuum system is just that slow, it doesn't make good sense for a 50 second delay after the t-case has already reached 4x4 mode?
It still seems like an awful long time to me.
I did see a 15 second disengagement timer though.
Unless the vacuum system is just that slow, it doesn't make good sense for a 50 second delay after the t-case has already reached 4x4 mode?
#15
#16
Originally Posted by n3elz
Good reference, Joe -- but where does it confirm 50 second engagement times? I didn't see that. Is that just what people experience or is it a spec somewhere that you know of?
It still seems like an awful long time to me.
Unless the vacuum system is just that slow, it doesn't make good sense for a 50 second delay after the t-case has already reached 4x4 mode?
It still seems like an awful long time to me.
Unless the vacuum system is just that slow, it doesn't make good sense for a 50 second delay after the t-case has already reached 4x4 mode?
However, check out page 3 of the TSB, top left hand column in bold type:
NOTE
DURING ALL DIAGNOSTICS (HOIST OR ROADTESTS), NOTE THAT THE ENGAGEMENTVACUUM PULSE LASTS FOR APPROXIMATELY 50 SECONDS. WHEN DIAGNOSING THE TRUE STATE OF THE HUB LOCK SYSTEM, LET THIS AMOUNT OF TIME PASS BEFORE CHECKING FOR ACTUAL SHAFT ENGAGEMENT...
DURING ALL DIAGNOSTICS (HOIST OR ROADTESTS), NOTE THAT THE ENGAGEMENTVACUUM PULSE LASTS FOR APPROXIMATELY 50 SECONDS. WHEN DIAGNOSING THE TRUE STATE OF THE HUB LOCK SYSTEM, LET THIS AMOUNT OF TIME PASS BEFORE CHECKING FOR ACTUAL SHAFT ENGAGEMENT...
Who knows, maybe Ford knew the PVH systems were prone to vacuum leaks before they even left the factory!
#17
#18
Originally Posted by Rockledge
Of course, just because the engagement vacuum pulse is approx. 50 seconds long doesn't always mean it takes that long in real life, but the fact that Ford designed it that way makes me think that maybe long engagement times were anticipated for some reason.
Who knows, maybe Ford knew the PVH systems were prone to vacuum leaks before they even left the factory!
Who knows, maybe Ford knew the PVH systems were prone to vacuum leaks before they even left the factory!
Well, that makes sense then. If they say you have to wait 50 seconds before you can consider it "failed", then it could take up to 50 seconds.
I don't think I'd keep those if I had them, lol.
#20
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