I clicked my dash button to lock the differentials. "Testing" my system and it seems to be locked, the light doesn't turn off on the dash and I'm still chirping around all corners... still locked... any ideas?
So I’ve been trying to still diagnose this, I had pulled the motor and was doing the 3sgte swap and decided to sell it and now the stock engine is back in and I was hoping while it was out and then back In the diff would have been unlocked. No go, vacumm lines seem to be all correct.. I’m so lostI got your PMs... I was off-grid for a while, just got back.
The center diff lock system on the manual trans Alltrac Camry is vacuum actuated. The best picture I have is below:
Same trans you have (though different motor). The actuator is the vacuum canister on the right with 4 vacuum lines going to it. Those lines run up to the two VSV (vacuum switching valves) on the top of the firewall:
The vacuum lines run like this:
Vacuum line from intake manifold -> check valve on vacuum canister -> vacuum canister -> vacuum line up to Y that leads to both VSVs -> 1 vacuum line to each side of the vacuum actuator (2 total). The vacuum canister is integrated into the actuator and looks like one unit externally.
One VSV is 'normally open" and one is 'normally closed'. This should leave a constant 'pulling' force to hold the center diff lock open during normal operation, and reverse it for locked operation. The actual locking happens inside the transfer case portion of the transmission and the light on the dash is turned on by the position switch on the top of the transfer case (white connector, in line with the prop shaft output).
The actuator arm itself is covered by a rubber boot (below the 4-bolt mounting plate in the top pic), so it would be fairly hard to mess with that in the car or see if it is moving with switch actuation.
So, there's the system overview... not sure where to start with debugging it though!
The only problem I had with that when I had the car was I hooked up the vacuum source to the wrong port on the engine (non-stock engine...). That's not a problem you should be having.
Maybe check the following:
If the locking sleeve is stuck, it make just take some time and maybe manual operation to get it unstuck. Let's hope the actuator is not leaking...
- 12V between the two connections on each VSV when button pressed, ~0V when button not pressed
- Vacuum always on 'input' connections to each VSV (from the Y)
- Switching (and opposite) vacuum on each VSV output to the actuator
I'm assuming you have driven it and it still 'chirps' around corners...So I’ve been trying to still diagnose this, I had pulled the motor and was doing the 3sgte swap and decided to sell it and now the stock engine is back in and I was hoping while it was out and then back In the diff would have been unlocked. No go, vacumm lines seem to be all correct.. I’m so lost
It stays in an 'unknown' state. Basically, whatever it has been in previously. When mine was missing vacuum after the engine swap (put vacuum feed on a non-vacuum source) it was sometimes locked and sometimes unlocked.What’s the default fail safe position should there be no vacuum?