Front e-locker install: Solved (1 Viewer)

[sdb999]

96' oem front locker, axle on the bench.
Prior to rebuild this e-locker worked fine during bench test. 12v at pins 2 and 3 would lock/unlock by reversing polarity. Repeatably. Now after rebuilding the axle ready to reinstall e-locker following FSM. Inside differential gear rack is in the correct position, fully locked, with first tooth on the center-line of mounting hole. Actuator is not clocked correctly, match marks are not in a vertical orientation. FSM states 1.5v to align the marks.....nothing moves...just a click. 9volts, same. 11 and 12 volts, ditto. This actuator was pretty rough, I was surprised it worked at all initially, but I had a brand new spare so I pulled it out. Brand new actuator, same issue, match marks are clocked wrong. Same attempts....nothing....it wont budge.

What is the FSM leaving out of this procedure? I'm at a loss, any help greatly appreciated.
Thanks, S

 

[sdb999]

Wow, crickets. Can't say that's ever happened.

 

[retrofive]

Wow, crickets. Can't say that's ever happened.

Hang tight, it's monday. Sorry I don't have an answer, but bump to top for ya

 

[mudgudgeon]

I was going to suggest maybe burnt out windings in the actuator motor but if you asked a complete new one in, then I guess that counts it out.

I had a CDL actuator with burnt windings in the motor (my fault) bench tested fine, but as soon as it had to deal with any load it had no strength.

 

[sdb999]

Thanks all for the thoughts and bump. Oddly enough the new one moved in one direction on the bench test but would not return with polarity switched, and has been motionless since. I’ll put the meter on the internal limit switches and see what state they’re in. I can’t think of anything else to check.

 

[sdb999]

Thanks all for the thoughts and bump. Oddly enough the new one moved in one direction on the bench test but would not return with polarity switched, and has been motionless since. I’ll put the meter on the internal limit switches and see what state they’re in. I can’t think of anything else to check.

 

[sdb999]

Work pulled me away but I'm back on it this past weekend. Old Actuator was disassembled and is beyond repair really, the new actuator that would not bench test successfully has been returned. Another new unit is in transit, I just want to double check my methods before it arrives:

True/False

• Testing on the bench is %100 ok and safe on these actuators, 12v to pins 2 and 3 only will confirm operation.
• Negative on pin 2 = Unlock. Negative on pin 3 = Lock.
• 12v applied only briefly until unit changes position, then removed, don't toast anything.

The FSM is a bit cryptic on installing the actuator and assumes differential is removed, but as far as I can tell there is no need for the "clocking" during insertion. I suppose I could remove the studs to allow this procedure but would like to know if anyone else has replaced an actuator by simply remove/replace on the vehicle.
Thanks, s.

 

[ppc]

You need to read the FSM specific procedures for testing, removal and reinstallation of the actuator. It specifically cautions against applying "battery voltage" directly to the actuator. Instead it details using a 1.5V dry cell battery to set the proper alignment. I couldn't find the reference in the manual but I recall the suggestion to using a 9V battery to test the actuator which implies limiting the amperage.

 

[sdb999]

That's part of my confusion, motor on actuator is clearly labeled 12v, yet FSM does indeed show 1.5v being used. I suppose regardless of source I should limit current with a fuse of some sort when testing on the bench. In the vehicle it likely gets full 12v but is controlled via the limit switches so I suspect the FSM is protecting us from ourselves. Popular trend of late.
Thanks for the input, S.

 

[sdb999]

Axle still on the bench with the second brand new front e-locker actuator. Out of the box it moved with 1.5v to align, installed in the axle and won't move with 1.5v applied. How do you test this if you're not allowed to apply 12v when installed in the axle? I'm at a loss.

 

[sdb999]

Ultimately two core issues delayed the fix, both self-inflicted for the most part:
1. Pin 2 on positive to Unlock, Pin 3 on positive to Lock. (early on internet screen capture was wrong, I should have confirmed)
2. Clocking the actuator gear prior to installation is critical, one tooth makes a difference.

Related notes and thoughts:

• The front axle and differential section of the FSM is ok, but incomplete. Locking Section SA-89 is where you want to go. It's all there in one spot.
• The FSM shows a detailed image (in both sections) illustrating the criticality of the alignment between actuator gear and gear rack inside the differential. You will never see this image in real life, but study it because you will have to "see" it in your mind.
• For testing actuator on the axle: 12v works fine only using pins 2 and 3, I protected with 10 amp fuse and it never blew. (shown in FSM in section SA-89)
• For testing actuator on the bench: 1.5v works fine and moves the motor very slow for clocking the gear.

Odd Stuff:
If for some reason the actuator no longer responds to voltage (12v or 1.5v). This happened multiple times to me on all three actuators I had for this endeavor. I can only guess at the cause, but the fix I'm absolutely certain of. With actuator on the bench, remove the two small 8mm screws and slowly/carefully lift the cover off the gear box area. You will likely have the sector touching one of the hard stops (in my case always the locked position) rotate it off the hard stop and re-assemble. 1.5v will but it back to the correct spot for installation and you're on your way. Also, while the gear box section is off you may confirm motor operation with 1.5v.

Clocking:
I followed the FSM to the letter, and with multiple installations and tests the motor failed to respond after 1-3 lock/unlock cycles (it was hanging on the hard stop/locked position). I marked the clocking position and repeated with no change. I then went one tooth off my mark. Victory! I was willing to go one tooth the other direction, but I guessed right the first time. Because you will never be able to see the actual engagement of gear and rack, you just have to be consistent in your methods. I obviously was not achieving the perfect mesh from my first clock position and I trusted it too long.

Thanks all for suggestions and sympathetic ear. Just few brakes lines away and it's ready to go in the truck.
S.