Spotty diff. engagement (1 Viewer)

[boomerzoomer99]

Having a weird issue with my ‘96 LX450. The CDL light is not coming on when I engage low range.
I installed the CDL button, and when I use the button, the CDL and ABS lights come on and the locker seems to engage.
I usually engage the CDL and drive in high range, and I seem to be able to engage the CDL in low range when I use the button. Beyond this, when I’m in low range with the CDL manually locked, the rear locker doesn’t always engage. Sometimes it will, sometimes it won’t.
Is this indicative of a problem, or is it just a harmless quirk?

 

[ppc]

The 96 model did not come from the factory with the dash switch, it was added at some point. When installing the switch it is common to also do the "Pin 7 Mod" which eliminates the automatic CDL engagement when shifting to low range. Search on that term for more info. If that mod was not done then the 4LOW position switch on the rear extension on the transfer case most likely is the problem. Again there are a large number of posts you can search for more info. Once the CDL dash light illuminates the front and rear lockers can be locked. No CDL dash light then front and rear indicators on the dash will just flash. The rear locker can be finicky and won't instantly lock without slippage between the wheels by spinning or going into figure eights. Just like the 4LOW sensor there is a sensor on the axles that will keep the dash light flashing if not working consistently even though the locker is enabled. If you frequently turn the lockers on/off it can free up and work more consistently.

 

[mudgudgeon]

when I’m in low range with the CDL manually locked, the rear locker doesn’t always engage. Sometimes it will, sometimes it won’t.
Is this indicative of a problem, or is it ju

This can be normal.
The locking mechanism in the rear diff has very coarse locking gears (6 teeth). If you don't get much wheel slip, the gear may not align and the diff won't lock.
This is not really a problem because in this scenario, you have good traction to both rear wheels.
I've found if everything is working, offroad the rear diff may not lock when you switch it to lock. I find they have always locked when traction is poor enough to get a lot of wheel slip.


To test the rear locker, find a gravel carpark.
Lock CDL, rotate the switch for the rear locker, then slowly drive in a tight circle.
This will rotate the wheels different amounts, and should allow the rear diff to lock fairly quickly every time.

You can do this on asphalt, but do so with extreme caution as the driveline will bind up FAST on a high traction surface

 

[LandLocked93]

Having a weird issue with my ‘96 LX450. The CDL light is not coming on when I engage low range.
I installed the CDL button, and when I use the button, the CDL and ABS lights come on and the locker seems to engage.
I usually engage the CDL and drive in high range, and I seem to be able to engage the CDL in low range when I use the button. Beyond this, when I’m in low range with the CDL manually locked, the rear locker doesn’t always engage. Sometimes it will, sometimes it won’t.
Is this indicative of a problem, or is it just a harmless quirk?

Sounds like the actuator motor is due for refresh or replacement. The procedure as outlined on the back of the sunvisor, and indeed for most 4x4's of this vintage, is to engage lockers while in neutral, reverse 10 to 15 feet, then go forward as normal. This works every time for me, and I know my lock actuators are due for go-through.
I presume the figure 8 thing also works...but that seems indicative of an issue (and a PITA yeah?) if you have to do that every time a lock is engaged. Guessing the act of doing a figure 8 helps a weak actuator motor engage the 'forks' more readily. I wouldn't have the patience for it frankly.