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Yet another difflock dies!

Posted: 06 Apr 2018 10:41
by Anthony Forgey
I killed my difflock

I have been pedantic about engaging and disengaging my factory rear locker. Always engaged it while stationary. If the light still flashed I'd crawl forward slightly to allow it to engage before pulling off. I don't use it often, but when I do I need it.

Over the long weekend I was camping at Swartruggens and doing some offroad driving. Difficult cross-axle obstacles one after the other. I engaged the locker and only got stuck on a breakover where the SWB jeep in front of me got stuck and I pulled him out. Knowing the breakover was too much I approached from a different line but it meant that I'd be cross axled and without the locker I wouldn't make it. I put the locker on and tried to do the obstacle. I got stuck and one of the guys in the group said I should engage the locker. I double checked... the locker light was on. a couple of guys helped push me backward and I bypassed the obstacle.

Johan Swift couldn't believe that I was able to follow the 37" twin locked SWB Rubicons! :surprised: . He was even more stunned to find out that I did it with open diffs :surprised: :surprised: :surprised: . But we all know Patrol's are good offroad vehicles. He always refers to my vehicle as "daai plaas implement" :rolleyes:


What checks have been done?
I've since checked the solenoids... they both work.
Checked the mechanical movement of the actuator by taking off the sensor and putting a screwdriver against the actuator while engaging the locker.... it moves freely...in and out when vacuum is applied.
I've checked the vacuum on both lines at the actuator... Plenty... about 6oommHg, higher than the 500mmHg minimum required (according to the manual)
Vacuum check.jpg
Vacuum check.jpg (30.09 KiB) Viewed 4674 times
I put it up on jack stands, engage low range, first gear, engage locker and I can stop the one rear wheel with my hands... the other keeps turning. Slight knock, knock, knock knock sound coming from the diff.

So its a mechanical issue inside the diff
after much reading I found some pics of some of the things which could go wrong:

Broken Fork
Broken fork.jpg
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Broken/damaged side gear or dog drive teeth (the two dog drive teeth engage with this gear to activate the locking of the diff)
Side gear.jpg
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Broken actuator shaft
Broken Actuator rod.jpg
Broken Actuator rod.jpg (53.93 KiB) Viewed 4674 times

The only way to know is to remove the carrier and inspect. I don't have the $ at the moment to have it repaired. I can do it, but it is a horrible job, messy, and the carrier is bloody heavy. So, for the moment I'll just drain the diff oil to check for broken bits in the drained oil. once I'm happy that there's no loose material, I'll fill the diff with oil drive around locker-less

Re: Yet another difflock dies!

Posted: 06 Apr 2018 11:45
by hugejp
:imsorry:

Horrible news mate!

Which rear diff does your truck run? The H233 or the H260?

Good luck, I hope its not too bad inside.

Re: Yet another difflock dies!

Posted: 06 Apr 2018 12:06
by Anthony Forgey
hugejp wrote: 06 Apr 2018 11:45 :imsorry:

Horrible news mate!

Which rear diff does your truck run? The H233 or the H260?

Good luck, I hope its not too bad inside.
H233 I believe. the 260 is on the 4.5 petrol

Re: Yet another difflock dies!

Posted: 06 Apr 2018 13:59
by Rhett
Eish, sorry!

But now that this has happened to you, I will be able to learn from your dilemma. My diff-lock still doesn't operate properly and I have a feeling it's one of the issues you suspect:
  • Broken/damaged side gear or dog drive teeth (the two dog drive teeth engage with this gear to activate the locking of the diff)
I think draining the fluid and looking for crumbs is my answer too.

Re: Yet another difflock dies!

Posted: 06 Apr 2018 15:23
by hugejp
Yip!

Drain & check...

The one time you dont want to find a shiny thing!

:pray:

Re: Yet another difflock dies!

Posted: 06 Apr 2018 16:54
by Anthony Forgey
Oh dear....

Drained the diff oil. It wasn't new, but not bad at all.

Stuck to the drain plug magnet were shards of what I think are side gear teeth.
IMG_20180406_142135.jpg
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IMG_20180406_143149.jpg
IMG_20180406_143149.jpg (70.25 KiB) Viewed 4601 times
IMG_20180406_154421.jpg
IMG_20180406_154421.jpg (68.49 KiB) Viewed 4601 times
Strained the oil and found 3 more tiny shards. I shaped a piece of wire and dug around in the drain hole to scrape any more out but there were no more.

I do have to take the carrier out at some point and repair this but for the moment, I put the oil back and will drive without difflock.

Re: Yet another difflock dies!

Posted: 06 Apr 2018 17:05
by hugejp
Are you sure its all out??

You dont want to be driving with grinding paste in the diff...

:mytwocents:

Re: Yet another difflock dies!

Posted: 06 Apr 2018 17:26
by Pieter B
Wont it be cheaper to source a 2nd hand diff from Dawid?

Re: Yet another difflock dies!

Posted: 06 Apr 2018 19:53
by hugejp
Probably the cheaper option yes.

Re: Yet another difflock dies!

Posted: 06 Apr 2018 20:01
by hugejp
I recon you could get an even better price if you handed in your old axle too...

I recently had both my axles swapped out for Manual 4.8 axles by Errol. He gave me a really good price to do it & he was very fast too.