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More diff woes,front won’t disengage!

RBG21

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Jun 20, 2021
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So I was trying to sort the centre diff lock out, changed the sensor and sadly that didn’t work so bridged the connection on the plug with a paper clip and straight away I got the CDL and ABS light up on the dash so I’m guessing an issue with the actuator instead?.

Either way I thought I’d try the front and rear locks as I believe the front locker needs to be engaged for the front diff to be removed?.
Anyway nothing happened so turned the switch back off, then moving off a friends drive where we were working on it the front locker engaged on its own!, switch off, centre diff not locked or tricked into the car thinking it’s locked!, tried going back and forth, luckily it’s gravel so a bit loose, tried getting the plug off and using a 9V battery as a technique described on ih8mud and nothing!.

The diff does have an oil/grease leak from the back where the prop connects, the knuckles are leaking and I’ve got a front axle rebuild kit and I’ve managed to find a decent diff from a breakers.
As it’s locked at the moment this means the front diff will be removable but my worry is when the new diff goes in, I won’t be able to get it unlocked either, does this sound like the actuator in the front has gotten stuck too?, there is somewhere on eBay that repairs the actuators and posts them back so was thinking about removing them and sending them off, not really sure how to sort this out.
It’s obviously completely undriveable at the moment.

I did have to drive it about 1.5 miles to get it to where it’s going to be getting worked on which I did very slowly and with great difficulty and turning very gently when I had to.
 
Can you put power direct to the actuator to unlock it ?
 
I am definitely not the best person to advise you on this but apparently the magnets inside the actuator can come free which might explain how it locked itself .

On the bright side that would suggest the actuator can be dismantled and repaired with little more than glue .
 
Can you put power direct to the actuator to unlock it ?
I did try that following the instructions from ih8mud but sadly no joy, no noise at all, I think I put the wires in the right contacts and nothing, I did think about trying the bottom row of connections on the plug instead but didn’t want to risk sending power somewhere it’s not meant to be.
I am definitely not the best person to advise you on this but apparently the magnets inside the actuator can come free which might explain how it locked itself .

On the bright side that would suggest the actuator can be dismantled and repaired with little more than glue .
That would make a lot of sense actually, I was going to try and get it off yesterday but typically one of the bolts was rounded off and very tricky to get to on the floor.

I’ve managed to get it to the truck fitter at work whos pretty knowledgable about axles and got a pit to do it in after hours so going to do the seals etc with the Roughtrax kit, think it’s pretty obvious it needs a new diff now too so when the old one comes out I’m going to take it apart and hopefully sort it out.
 
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Yeah we tried that but sadly nothing, by the looks of things the actuator needs pulling apart, or replacing, they’re really expensive though for what they are!, so going to try and fix it first.
 
Yeah we tried that but sadly nothing, by the looks of things the actuator needs pulling apart, or replacing, they’re really expensive though for what they are!, so going to try and fix it first.

Agreed, assuming you can get it off of the axle itself, damn bolts will break the first chance they get, mine had been playing up and becoming slow to engage, but with thr 80 having been sitting around for over ten months, apart from a drive up and down the dirt track outside my house trying to keep it in order, I doubt it will be reliable until I have had it apart and cleaned it up.

Regards

Dave
 
Agreed, assuming you can get it off of the axle itself, damn bolts will break the first chance they get, mine had been playing up and becoming slow to engage, but with thr 80 having been sitting around for over ten months, apart from a drive up and down the dirt track outside my house trying to keep it in order, I doubt it will be reliable until I have had it apart and cleaned it up.

Regards

Dave
I’ve had a quick look online and they don’t look too tricky to clean up, it seems more that getting them off the diff is the tricky part like you say.

Think the one off the transfer box is going to have to come off too to get the CDL working too as it had a new sensor and that didn’t seem to do the job, bridging the wires with a paper clip made both the ABS and CDL lights come on.
First priority though is getting the new front diff in and the lock disengaged after the axle seals etc have been done.
I will worry about the CDL later!.
 
If you remove the actuator on the front diff, you can unlock it manually. Just make sure you synchronise the ECU, actuator and diff when you put it back together (just making sure they're all in the same state - all locked, or all unlocked).
 
If you remove the actuator on the front diff, you can unlock it manually. Just make sure you synchronise the ECU, actuator and diff when you put it back together (just making sure they're all in the same state - all locked, or all unlocked).
That’s really helpful, thanks.
At the moment the switch is set to off but it’s still coming up with the front diff lock light and the diff is locked.

In theory would the best thing to be to get the old diff out locked as apparently it needs to be locked to remove it, put the new one in locked then unlock it manually with the diff lock switch off and unplug the power/sensor to the actuator so the ECU thinks it’s unlocked too?.

I’m not too worried about the actuator getting fixed at the moment, just want the new diff in and unlocked for now, I can get a new actuator at a later date if it can’t be repaired.
 
Your plan should work, but no need to unplug the sensor to fool it, just run the actuator before re-installing it, so everything is in the same state, then refit.
 
That’s good to know, so for now if the actuator is knackered, would it work to put the new diff in locked so it fits, unlock it manually and move the actuator to the unlocked position and reinstall?.
If I can’t sort the one on it out I will put another one on it at some point but having a front diff lock isn’t a huge priority, it will be something to do down the line.
 
Whichever motor you use you need to plug it in and cycle it a few times with the switch to ensure it works and sets to the unlocked position. then install with the diff in the unlocked condition. As Jon said.
 
You dont need to have the diff locked to remove it. The only time it “needs” to be locked is if you are doing a front axle service. There have been reports of people having trouble getting one of the axles back into place if they dislodge the locking mech in the diff. I have never had this problem and usually forget to lock the diff before working on it.
 
I hope to overall my front axle over the coming weeks, the front diff lock is not engaging, and FWIW I have never locked the front when removing the axles.

Regards

Dave
 
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