How to fix 200-Series refusing to engage low-range (transfer actuator malfunction) (1 Viewer)

[cnd]

I got stuck in sand, and decided to play with "crawl control" ... first time I'd ever needed low-range ... but low-range would not engage. Later, mechanic diagnosed actuator fault, and (so they say) attempted "manual activation", which also didn't work, so they replaced it: which cost $4001 (AUD). It's a huge all-day job pulling it out, so most of that was labor. I asked for the old one to "play with"

After it was fixed, I found a video describing the problem: - easy to do after-the-fact, because beforehand, I had no idea that the name of the broken thing was "transfer actuator".

Turns out that all you need to do is remove 5 screws on each side, and clean it with a Q-Tip.

So yeah - to share with you the $4001 cost of that lesson - I'm posting here!

The cause of the fault is build-up of muck on the sliding position contacts. Technically, you could even fix this problem in just a couple of minutes with just a 9v battery* and some wire (making the motor move, even a tiny bit, will re-contact the sliders). If you want to try this - you'll have to study the wiring diagram REALLY CAREFULLY - if you run the motor too far the wrong way, the grub screw comes off the drive wheel, and you'll need to remove those 5 screws to turn it back.

* FYI - the drive motors draw 200ma at 13.8 volts under no-load. The "+" and "-" to those drive motors are the end-two contacts on the plug.

To fix this yourself, pull off the covers, clean the crap off the triple-contact slider and also off the slide-plate itself, move around some of the yellow grease to re-lubricate the slide, and put it all back together.

Set of high-res images and a wiring diagram are here: Index of /img/actuator - https://chrisdrake.com/img/actuator/ (not sure why this forum blocks big images...)

Happy to answer questions if anyone has any. I also fixed my old one - if anyone wants it, lemme know.

 

[lx200inAR]

This thread is another good resource.

Thread 'Transfer Case Tuneup and Fix'
Transfer Case Tuneup and Fix - https://forum.ih8mud.com/threads/transfer-case-tuneup-and-fix.1215394/

 

[KLF]

That photo reminds me of the inner guts of an e-locker actuator, which I have rebuilt quite a few over the years. I assume there is a large o-ring on the cover that must start leaking, just like the e-locker. And I also assume, just like the e-locker, that you can't buy just the o-ring when it does. Bummer.

Perhaps this is a high mileage PM item...

 

[bloc]

That photo reminds me of the inner guts of an e-locker actuator, which I have rebuilt quite a few over the years. I assume there is a large o-ring on the cover that must start leaking, just like the e-locker. And I also assume, just like the e-locker, that you can't buy just the o-ring when it does. Bummer.

Perhaps this is a high mileage PM item...

Elocker actuators usually leak from corrosion attacking the oring surface (the half dozen I’ve rebuilt this was the cause anyway), in this case it’s plastic so that isn’t a concern. It really seems to be the grease drying up, carbon on the contacts, almost never getting used…

 

[KLF]

Elocker actuators usually leak from corrosion attacking the oring surface (the half dozen I’ve rebuilt this was the cause anyway), in this case it’s plastic so that isn’t a concern. It really seems to be the grease drying up, carbon on the contacts, almost never getting used…

Yeah the soft cast aluminum case starts to corrode which eventually attacks the thin o-ring. Then the o-ring gets all hardened and crusty, falls apart. Then water gets inside and causes all sorts of damage to the contacts and the motor. Many years ago I actually found a place local to me that sells o-rings of all sizes, but the smallest quantity was 1000. He pulled a handful out of a bag and gave them to me. I gave them away with all the parts I included when I sold my '87 Xcab.

 

[Willie G]

This might be helpful to someone: Grainger - O-ring splicing kits

50 years ago these were a necessity.

 

[cnd]

That photo reminds me of the inner guts of an e-locker actuator, which I have rebuilt quite a few over the years. I assume there is a large o-ring on the cover that must start leaking, just like the e-locker. And I also assume, just like the e-locker, that you can't buy just the o-ring when it does. Bummer.

Perhaps this is a high mileage PM item...

Both the O-rings were still in great shape, and there was no sign of any dust or moisture having made its way in (not past the O-rings, and not through the breather tube either). I read someplace that the computer "tests" these things on start-up with a short pulse of power - I imagine that a few years of high-amps regularly going through the exact same spot on the contacts is the cause of my issue: there are miniscule "pits" worn into the surface of the brass where the contacts rest, which almost certainly are going to contribute to "sparks" and the carbon buildup I saw.

 

[NikP]

Before getting to serious about tearing things apart, try engaging it repeatedly. Mine wouldn't engage and during a period of a week I would routinely try to engage 4-lo. Eventually it engaged and now it engages every time. I made sure the transmission was warmed up. I have a habit now of engaging 4-lo every week.

 

[cnd]

engaging it repeatedly

Grr - that would have saved me a *lot*. The problem on the inside looked very minor to me.

I just checked my mechanics $4001 work.
He had not connected the breather tube.

 

[isthatalexus]

Grr - that would have saved me a *lot*. The problem on the inside looked very minor to me.

I just checked my mechanics $4001 work.
He had not connected the breather tube.

You should get that $1 back.

Also, good on you for wrenching on it yourself. Just don't fark up those submicro switches, but do consider contact cleaning them if the breather hose has been off and you see evidence of corrosion.