Transfer Case Tuneup and Fix (1 Viewer)

[grinchy]

Try to start the truck. That sometimes will kick it over. Also charge your battery and give a shot on startup with the fully charged battery.

The cdl can run in 4h, no need to shift to 4lo to try that out.

Some have reported success after tapping on the mechanism box. Though I admit I might be confusing this with some other stuck shifter in my past.

 

[afgman786]

@Diff Kraken what he said above. Keep the truck in 4lo and tomorrow when you start her up should be just in 4lo and then you back go back to 4hi.
If I test CDL on the road I do it in 4hi that way if it doesn't work I'm fine

 

[Diff Kraken]

Thanks all! So... I was able to fix it just now. It's back in 4Hi and the truck is functioning and driving fine at the moment.

I'm still not sure about the actuator, but this immediate issue of not being able to shift out of 4Lo appears to have been related to the 4Hi, 4Lo selector dial itself. I was out in the truck to try what @grinchy suggested. I charged up the battery a bit with a LiPo jump starter pack and turned the truck over, maybe unrelated, but the CDL light was no longer flashing when the truck started- and it said 4Lo on the dash. Then I switched it to Neutral and turned the selector to 4Hi.... it didn't do anything and still said 4Lo. I tried that a few times and thought I should look at the selector dial itself. I pulled the selector off and found a metal sleeve loose in the switch housing in the dash. I stuffed the metal sleeve back into the dial selector that I had pulled off the dash, and the metal slid in and clicked into place. I then returned the dial selector to the dash and turned the dial to 4Hi.... success!!!

I could feel it immediately shifted to 4Hi and the dash lit up like a Christmas tree! ABS,Check VCS message, Check PCS message, etc... drove around and the ABS was definetly turned off- I could slide in the rain with quick braking as a test. Turned the truck off and parked for about 5 minutes. Turned it back on and it's all back to normal as if nothing happened.

I'm certainly wary of the 4Lo and CDL use now, so I'll leave it alone and play around with it again on some weekend soon when I've got free time to take it apart.

 

[grinchy]

Thanks all! So... I was able to fix it just now. It's back in 4Hi and the truck is functioning and driving fine at the moment.

I'm still not sure about the actuator, but this immediate issue of not being able to shift out of 4Lo appears to have been related to the 4Hi, 4Lo selector dial itself. I was out in the truck to try what @grinchy suggested. I charged up the battery a bit with a LiPo jump starter pack and turned the truck over, maybe unrelated, but the CDL light was no longer flashing when the truck started- and it said 4Lo on the dash. Then I switched it to Neutral and turned the selector to 4Hi.... it didn't do anything and still said 4Lo. I tried that a few times and thought I should look at the selector dial itself. I pulled the selector off and found a metal sleeve loose in the switch housing in the dash. I stuffed the metal sleeve back into the dial selector that I had pulled off the dash, and the metal slid in and clicked into place. I then returned the dial selector to the dash and turned the dial to 4Hi.... success!!!

I could feel it immediately shifted to 4Hi and the dash lit up like a Christmas tree! ABS,Check VCS message, Check PCS message, etc... drove around and the ABS was definetly turned off- I could slide in the rain with quick braking as a test. Turned the truck off and parked for about 5 minutes. Turned it back on and it's all back to normal as if nothing happened.

I'm certainly wary of the 4Lo and CDL use now, so I'll leave it alone and play around with it again on some weekend soon when I've got free time to take it apart.

It just needs a little use. Probably hadn’t been used in many years. It’s a fairly common problem.
Good work finding the mechanical fault!

Use the diff lock daily for a couple weeks. You can use it any time it is wet, or on a straight road in the dry.

4lo can be used on any street doesn’t need to be gravel. Truck is. Full time 4wd already.
I run mine once a week for a couple blocks on my residential street to try to keep it from freezing up. Same with the cdl.

If you turn them on off over a few days and then do monthly switching all should be good

 

[grinchy]

Oh, usually an on off cycle will get rid of the fault lights, as you’ve found out.

 

[linuxgod]

Oh, usually an on off cycle will get rid of the fault lights, as you’ve found out.

Bingo.

Most importantly, until you're sure the CDL and 4Lo switches are working correctly, don't try to use them until you drive for ~10 minutes or so and warm the transfer case up. These will often flash if you start the vehicle and just try to activate them, unless your actuator motor is in tip top shape. They are much more likely to work in my experience once the transfer case is warm.

And as @grinchy points out, if you get the flashing, once the vehicle is warm you can often just turn the vehicle off completely and then back on and it will clear and then the actuator will work fine.

Note that there are 2 flashing speeds for the CDL light. faster flashing means the actuation failed and requires a restart of the vehicle. slow flashing means the actuator is trying to work but you may need to drive a bit and/or turn (or straighten) your steering wheel to get the mechanism to line up and engage.

 

[isthatalexus]

Case study in the particular problem I had. I was getting "Check VSC System", techstream scan showed a MIL code C1340:

Center Differential Lock Circuit​

- Center differential lock switch - Center differential lock switch circuit - Four wheel drive control ECU​

It's likely many issues of flashing diff lights is a manifestation of some combination of contacts not working.

Removing the upper actuator half clearly revealed why. Corrosion buildup on some contacts. These wiped off relatively easily with some electronics cleaner on a blue shop paper towel.

View attachment 2346510

Checking things out a bit more, the corrosion was likely a symptom of another problem. This microswitch was also had internal corrosion and was failing. Probing with a voltmeter showed that is wasn't working consistently. The microswitch top (black) is clipped on and can be popped off to clean internal contacts. Both problems were probably further symptoms of a weakened and sluggish motor.

View attachment 2346515

I was able to open up this microswitch and with some careful effort (warning...very small components!), clean the corrosion off its tiny internal contacts to return it to operation. That did the trick and now the center diff lock is working without MIL errors.
View attachment 2346516

Good sir: I ain't no 'geneer or anything, so this might be dumb question. I'm trouble shooting the microswith on the 4LO actuator. Tiny bits are clean and look as they should, however, the switch does not pull but .3 Ohms when closed. (edit: I was tired and inverted the resistance reading; At .3 Ohm the connection below is operating as it should. Will f/u with a more useful post about how I fixed this thing.) Same measurement methodology you introduced. I've been voltmetering around like a rabid yeti, and it seems like the connection between vertical riser and horizontal switch connection is bad...on one side. Thought I'd solder that beast into compliance, but could be I used not conductive flux from unmarked roll.

I was over the ski tips with the actuator earlier, but I'm way beyond that now. Any tips or suggestions are appreciated.

FYI: used CRC electronics cleaner (carefully) on the contacts, the kind that does not eat compounded plastics. Used dielectric grease on the circular contacts because it also does not eat plastic.

Thank you my friend are power.

 

[isthatalexus]

Bingo.

Most importantly, until you're sure the CDL and 4Lo switches are working correctly, don't try to use them until you drive for ~10 minutes or so and warm the transfer case up. These will often flash if you start the vehicle and just try to activate them, unless your actuator motor is in tip top shape. They are much more likely to work in my experience once the transfer case is warm.

And as @grinchy points out, if you get the flashing, once the vehicle is warm you can often just turn the vehicle off completely and then back on and it will clear and then the actuator will work fine.

Note that there are 2 flashing speeds for the CDL light. faster flashing means the actuation failed and requires a restart of the vehicle. slow flashing means the actuator is trying to work but you may need to drive a bit and/or turn (or straighten) your steering wheel to get the mechanism to line up and engage.

I will attempt the warmup technique tomorrow, but know that the day thermo showed 118 degrees when I ran my unsuccessful test run this afternoon. Tanny operating temps are likely much higher, but it's certainly closer to operating conditions than genius OP's teens temps. And I mean 'genius' sincerely. What else can you call a man who uncovers yet another heel on this Achilles truck.

 

[isthatalexus]

Understanding that in these repairs I stand on the shoulders of giants (@TeCKis300 and others)...

I suspect that my biggest issues were the actuator's poor/inconsistent contact at the microswitch

(might be submicroswitch), and possibly the corrosion at the concentric electrical contacts. Disclaimer: I'm not a mechanic or doctor, and the Holiday Inn Express here is occupied by violent squatters; don't do this stuff unless you are ready to buy a new transfer case actuator assembly. For inspiration and to steel my nerves, I watched KenKej savagely restores these parts.

• concentric electrical contacts
  • Shop towel wipe up of grease on concentric electrical contacts
  • gently go over contacts on case floor with 150 grit sand paper (spray w/ CRC QD Electronic Cleaner cleaner, wipe out)
  • apply CRC Dielectric Grease (not harmful to plastics, robust, etc.)
• motor
  • tested fine on 12v bench test; saw no need to remove/break factory solder points
  • removed the big silver screw (south-end in picture) to remove the bracket
  • removing the bracket uncovered the small hole in the motor
  • covered and isolated motor with shop towel in same way as the switch (see pic below) and sprayed CRC Lectra-Motive Elecric Parts Cleaner inside, holding the motor-in-housing hole-side-down.
• microswitch
  • required several removal/install cycles for me to figure out and to fix
    
  • escalated to switch dissasembly; plenty of corrosion found in spite of having a relatively clean actuator housing
  • turns out the issue was twofold: corrosion at contacts and too-loose hinge mechanism
  • the tiny plastic hinge allowed z-axis travel (orthogonal to intended plane of travel) of the platstic arm, making good contact at full-up or full-down positions but wildly inconsistent Ohm readings at its resting plane/position.
  • did not have the talent/bravery to mess with plastic housing of microswitch to reduce the up-down looseness
  • did have sufficient recklessness to gently adjust the two copper arms 'upwards' (on workbench), downwards when in-situ, to improve firmess of copper-on-copper contact when switch is activated by rotation of actuator wheel.
  • how gently did I manipulate those copper arms? If you are reading this and are thinking about doing this, you are already using too much force.

Over the course of this repair attempt I un- and reinstalled the two actuator housings many times. I want to share some things that would have helped along the way, had I known them earlier. Credit to sixweeds over at tundras.com for great work on this issue with the Tundra cousin truck (among other info).

Next time I will remove the entire actuator housing (yes, can be done without dropping/cracking, etc.) to

• more easily service both CDL and 4LO actuator housings
• allow spray of penetrating oil into the push-rod housing/channel. I think they become less compliant over time, which causes the electronics in the actuator housing to work harder and degrade faster

The poaster over on tundras linked to a few good videos from a Tagalog-speaking mechanic in Saudi Arabia. The videos are all shot with the front-facing camera, so I grabbed the stream, inverted, and will drop the reinstallation gear-clocking information here. (original video)

Bottom line on installation: push the actuator rods all the way in. (NB: my truck was in 4HI w/ CDL not locked)

Clock gears as follows. And use a screw driver (or other long, flat thing) to hold gears in place while installing top-side housing. You may have to adjust the clocking slighly to line up with shaft teeth. Do so by pulling the housing, turning the larger gear below the motor, and going in for second approach.

Hope I'm not posting Captain Obvious(tm) stuff here, but it's likely. These are the things I wish I had known before doing the work, and hopefully they will, in turn, help someone else. Again, hat-tip and thank you to @TeCKis300 and @cogniz et. al here, that Tundra wranger sixweeds, and my boy KenKej on the tube.

 

[linuxgod]

Very nice write up @isthatalexus!

 

[TeCKis300]

Understanding that in these repairs I stand on the shoulders of giants (@TeCKis300 and others)...

I suspect that my biggest issues were the actuator's poor/inconsistent contact at the microswitch View attachment 3046437(might be submicroswitch), and possibly the corrosion at the concentric electrical contacts. Disclaimer: I'm not a mechanic or doctor, and the Holiday Inn Express here is occupied by violent squatters; don't do this stuff unless you are ready to buy a new transfer case actuator assembly. For inspiration and to steel my nerves, I watched KenKej savagely restores these parts.

• concentric electrical contacts
  • Shop towel wipe up of grease on concentric electrical contacts
  • gently go over contacts on case floor with 150 grit sand paper (spray w/ CRC QD Electronic Cleaner cleaner, wipe out)
  • apply CRC Dielectric Grease (not harmful to plastics, robust, etc.)
• motor
  • tested fine on 12v bench test; saw no need to remove/break factory solder points
  • removed the big silver screw (south-end in picture) to remove the bracket
  • removing the bracket uncovered the small hole in the motor
  • covered and isolated motor with shop towel in same way as the switch (see pic below) and sprayed CRC Lectra-Motive Elecric Parts Cleaner inside, holding the motor-in-housing hole-side-down.
• microswitch
  • required several removal/install cycles for me to figure out and to fixView attachment 3046441
  • escalated to switch dissasembly; plenty of corrosion found in spite of having a relatively clean actuator housing
  • turns out the issue was twofold: corrosion at contacts and too-loose hinge mechanism
  • the tiny plastic hinge allowed z-axis travel (orthogonal to intended plane of travel) of the platstic arm, making good contact at full-up or full-down positions but wildly inconsistent Ohm readings at its resting plane/position.
  • did not have the talent/bravery to mess with plastic housing of microswitch to reduce the up-down looseness
  • did have sufficient recklessness to gently adjust the two copper arms 'upwards' (on workbench), downwards when in-situ, to improve firmess of copper-on-copper contact when switch is activated by rotation of actuator wheel.
  • how gently did I manipulate those copper arms? If you are reading this and are thinking about doing this, you are already using too much force.

View attachment 3046442

Over the course of this repair attempt I un- and reinstalled the two actuator housings many times. I want to share some things that would have helped along the way, had I known them earlier. Credit to sixweeds over at tundras.com for great work on this issue with the Tundra cousin truck (among other info).

Next time I will remove the entire actuator housing (yes, can be done without dropping/cracking, etc.) to

• more easily service both CDL and 4LO actuator housings
• allow spray of penetrating oil into the push-rod housing/channel. I think they become less compliant over time, which causes the electronics in the actuator housing to work harder and degrade faster

The poaster over on tundras linked to a few good videos from a Tagalog-speaking mechanic in Saudi Arabia. The videos are all shot with the front-facing camera, so I grabbed the stream, inverted, and will drop the reinstallation gear-clocking information here. (original video)

Bottom line on installation: push the actuator rods all the way in. (NB: my truck was in 4HI w/ CDL not locked)

Clock gears as follows. And use a screw driver (or other long, flat thing) to hold gears in place while installing top-side housing. You may have to adjust the clocking slighly to line up with shaft teeth. Do so by pulling the housing, turning the larger gear below the motor, and going in for second approach.

View attachment 3046450


Hope I'm not posting Captain Obvious(tm) stuff here, but it's likely. These are the things I wish I had known before doing the work, and hopefully they will, in turn, help someone else. Again, hat-tip and thank you to @TeCKis300 and @cogniz et. al here, that Tundra wranger sixweeds, and my boy KenKej on the tube.

Excellent post! Thank you for sharing those additional details. Great to know that the whole actuator assembly can be reasonably removed.

Sounds like you got it all working again which is the most important part!

 

[Diff Kraken]

I still can't get my CDL to engage even if the truck is warmed up. With a 175k miles on the truck, $700 for a new actuator assembly seems like money well spent... I think I'll jump on this:

TOYOTA GENUINE 3641060112 ACTUATOR ASSY, TRANSFER SHIFT 36410-60112 | eBay

We are happy to take care of all your Genuine parts and accessory needs. We specialize in Japanese Auto Spare Parts: Toyota / Lexus, Nissan / Infiniti, Mitsubishi, Mazda, Subaru, Suzuki. Genuine OEM Parts.

www.ebay.com

And, as posted above, that guy's video shows how to make the swap while leaving the original rods in the transfer case:

 

[Diff Kraken]

I still can't get my CDL to engage even if the truck is warmed up. With a 175k miles on the truck, $700 for a new actuator assembly seems like money well spent... I think I'll jump on this:

TOYOTA GENUINE 3641060112 ACTUATOR ASSY, TRANSFER SHIFT 36410-60112 | eBay

We are happy to take care of all your Genuine parts and accessory needs. We specialize in Japanese Auto Spare Parts: Toyota / Lexus, Nissan / Infiniti, Mitsubishi, Mazda, Subaru, Suzuki. Genuine OEM Parts.

www.ebay.com

And, as posted above, that guy's video shows how to make the swap while leaving the original rods in the transfer case:

BTW- this means I'll have the old actuator assembly as an extra if someone wants it... someone can rebuild it/clean it up ahead of time and then just swap it out with their old one. Maybe then pass on their old one to the next MUDDER to do the same thing. This would reduce the risk of having the truck out of operation for an extended period of time. I'll also have the new rods that come with the new actuator if someone wants them.

 

[grinchy]

Per my service history, a dealer replaced my actuator around 180000 miles. It was already sticky when I got the truck at 209000 miles. It's probably going to have to come out and get R&R pretty soon. I try to use it at least once a week, and even then it now will stick maybe 1 out of 3 uses.

 

[Diff Kraken]

Per my service history, a dealer replaced my actuator around 180000 miles. It was already sticky when I got the truck at 209000 miles. It's probably going to have to come out and get R&R pretty soon. I try to use it at least once a week, and even then it now will stick maybe 1 out of 3 uses.

So you’re pretty much saying it might not be worth the cost to buy a new one if it’s going to need TLC after 30k miles?

 

[grinchy]

So you’re pretty much saying it might not be worth the cost to buy a new one if it’s going to need TLC after 30k miles?

Just data points. It might have not been used in that 30k miles at all . . . I have 233K at the moment, so it has gone about 50K before I'm considering an R&R. For a couple years once I got it working reliably again via use at 209k, up to about 230k, it worked really good, maybe sticking only once or twice a year.

 

[Diff Kraken]

Ok. I think I’ll go for it. I like the idea of having a new actuator and engaging it every other week moving forward.

 

[Diff Kraken]

I still can't get my CDL to engage even if the truck is warmed up. With a 175k miles on the truck, $700 for a new actuator assembly seems like money well spent... I think I'll jump on this:

TOYOTA GENUINE 3641060112 ACTUATOR ASSY, TRANSFER SHIFT 36410-60112 | eBay

We are happy to take care of all your Genuine parts and accessory needs. We specialize in Japanese Auto Spare Parts: Toyota / Lexus, Nissan / Infiniti, Mitsubishi, Mazda, Subaru, Suzuki. Genuine OEM Parts.

www.ebay.com

And, as posted above, that guy's video shows how to make the swap while leaving the original rods in the transfer case:

I’ll also point out that in the video the mechanic sprays penetrating oil around the rods in the transfer case to get them moving freely. That step might be crucial to restore easy operation of the actuator. I’ll plan to do that when I put the new actuator on. You guys might want to do that too.

 

[Diff Kraken]

In case anyone is wondering what the inside of a factory fresh actuator assembly looks like…

 

[isthatalexus]

In case anyone is wondering what the inside of a factory fresh actuator assembly looks like…

View attachment 3070613View attachment 3070614View attachment 3070615View attachment 3070616View attachment 3070617View attachment 3070618View attachment 3070619

I'm low-key blushing. Very nice.