Transfer Case Tuneup and Fix (2 Viewers)

[TeCKis300]

Transfer case actuator issues are not uncommon on the 200-series. Not much documented solutions other than exercising the mechanisms regularly. Here's my attempt to provide more information on where and what the actuator is, how to service the transfer case actuator motor, and potentially provide some fixes.

Two main parts siamesed together that compose the transfer case actuator which is a plastic housing hanging off the rear:
1) Upper motor and rod is the center diff lock actuator/gearset
2) Lower motor and rod is the Hi/Lo actuator/gearset

Access is pretty easy and quick. From underneath, remove mass damper (14mm head bolts), remove the transfer case armor (many 12mm head bolts). A wire harness retainer (10mm head). Remove 3 plugs. And a breather hose.

The actuator assembly cannot be removed whole as the rods are retained in the transfer case internally. The subassemblies (motor and gearset) can be pulled off relatively easily and I was able to get at them in about 30 minutes. Fortunately, these are the main trouble areas. Depending on what is worn or has failed, one can buy a new or used actuator assembly and swap in various sub-components.

Some typical actuator issues from other related models in my search:
1) Slow actuation
2) Grease stiffening up and binding
3) Limit switch failure
4) Electrical contact failure
5) Motor internal failure, or external wiring detached
6) Breather tube cracked or fallen off allowing water/contaminants into the upper center diff lock, causing motor/bearing corrosion and failure

Disassembly. This Tundra guide will give you an idea. Their actuator is very similar but different. Note, there is a primary gear for each actuator that is clocked against the actuation rod. This gear clocking/timing is different for the upper diff lock. When dissembling, it's critical to note how the gear is clocked. Best to leave this main gear in place on the actuator body when doing the upper diff lock, and keep the lower gear on the cover when doing the lower shifter actuator. Shimmy the covers off carefully to maintain clocking. Perhaps guiding with a flat instrument. Also try not to actuate rod or at least critically note its position if you are going to. The video author here is wrong in what each motors purpose is. Otherwise, a great orientation vid.

 

[TeCKis300]

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.

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.

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.

 

[TeCKis300]

Disclaimer: There is a real chance in doing damage by opening up the actuator and servicing sub-components. Or messing up the gear timing. Proceed at your own risk.

Actuators have been noted to weaken or bind over time. The motors that drive them can use tune-ups as internal contaminants and brush wear on the commutator can cause a loss of motor torque. Mine was notably sluggish at times and has been binding a couple times in winter. Most of the corrosion above I attribute to this motor wear.

The motor is captive in the lid by the rear terminals. At the rear of the motor is a single philips screw that holds a retainer. Remove this and it'll reveal a small hole at the bottom of the motor. Spray electronics cleaner (CRC Electronics Cleaner) directly into this hole, while holding the assembly with the motor bottom side down. Want the cleaner to drip back down, and onto a rag, rather than pool into the assembly/grease. This should clean it up internally to improve performance.

I bench tested with a 12V supply, and all runs hunky dory. Fully assembled back in the vehicle, the center diff now locks better and stronger than it ever has. In a split second rather than many seconds prior.

Repeat for Hi/Lo actuator motor if desired. Note again when disassembling, don't lose the clocking/timing on the gear!

 

[TeCKis300]

Testing some more today. I didn't have a problem with the transfer case hi/lo engagement. Still serviced it doing post #3 above with some electronics cleaner on the motor. The engagement is notably more positive. It happens like now, vs the system thinking about it. Center diff lock also works like lightening.

I attribute the failure in #2 post above to the motor having lost torque due brush wear and debris. Then the system having to try multiple times and hunt for engagement, causing upstream contact wear and corrosion.

 

[grinchy]

Brave! Good info to have available. My service record shows the actuator being replaced a couple times, most recently just before my ownership period. Even so I had 'sticky' 4lo for a few months while it worked out whatever demons were in there. Now locks ok, but not 'lightning' fast.

 

[Bunga]

Great info. This is a chronic problem. I like deoxit for contacts, but what lube do you recommend for the gears?

 

[TeCKis300]

Okay, lightning is way overstating it, but compared to the glacial pace hit and miss it was before, it now happens positively after hitting the switch. Probably 1 second.

In regards to lube, I didn't strip the factory lube on the gears. Even in my '09, the lube looked good. In spraying into the hole in the motor, I was making sure the cleaner dripped away from the assembly.

 

[linuxgod]

Thanks @TeCKis300!

Any idea if any of this self-tests on vehicle start? When I've had the dreaded flashing CDL it's always happened within a second or two of starting my vehicle - fast enough that the Nav system hasn't even booted to the Toyota logo yet.

 

[TeCKis300]

It's too bad the flashing CDL is such a generic indicator. There should be a MIL code that can be pulled with techstream that provides more context.

From what I've seen, I'm not so sure the vehicle exercises any of the actuators on startup. The flashing lights is possibly the ECU seeing some state switch or microswitch not match up with the expected position of the actuators. From my issue, it's obvious several contacts are prone to corrosion over time, and that may be what is causing the flashing CDL light at startup. To your point, it's happening too quickly for testing of any physical actuation. Leads me to believe it's the electronic switch contacts that are suspect for corrosion and cold leading to flashing lights. Physical actuation then exercising the contacts of corrosion and fixing the error.

 

[linuxgod]

It's too bad the flashing CDL is such a generic indicator. There should be a MIL code that can be pulled with techstream that provides more context.

From what I've seen, I'm not so sure the vehicle exercises any of the actuators on startup. The flashing lights is possibly the ECU seeing some state switch or microswitch not match up with the expected position of the actuators. From my issue, it's obvious several contacts are prone to corrosion over time, and that may be what is causing the flashing CDL light at startup. To your point, it's happening too quickly for testing of any physical actuation. Leads me to believe it's the electronic switch contacts that are suspect for corrosion and cold leading to flashing lights. Physical actuation then exercising the contacts of corrosion and fixing the error.

Not to make this thread about *me*, but...

When I tried there were no related codes stored in Techstream. Dealer couldn't find anything in it either. It doesn't immediately seem like a short since turning the vehicle off and back on won't clear it until the transfer case warms up.

Certainly could be corrosion. Do those contacts always end up in the same position? (I assume so). Not that corrosion couldn't get "fixed" with some usage but if it was corrosion I would expect the problem to happen more and more often over time as the contacts corrode more (or faster) and I'd expect it to happen during warm weather as well, not to be fine all summer but have issues as soon as the temps drop into the low-to-mid 40s. (i.e. A few years back I hadn't had any issues since maybe April, I "exercised" the CDL and 4Lo actuators in July, and the vehicle was fine driving to CO but as soon as we camped overnight in Breckenridge the first morning when it was in the low 40s I started the truck and the light was flashing).

In my case it tends to clear up without issue once the vehicle warms up and if I exercise the actuator it goes away, so I'm thinking maybe there was some crud (hardened grease?) in the transfer case that was got flushed out in the last fluid exchange. Granted it's only been ~10-12k miles since the last flush but I was shocked to have gone since last Sept without an issue. Probably jinxing myself here. FWIW I also swapped the 75W-90 I had in there with straight 75W Ravenol, so there's at least 2 variables at play I supposed, though I'm pretty sure the truck had the factory 75W-LF in it when I bought it at 49k miles and I had the flashing light issue then as well.

 

[TeCKis300]

All good points and we're still trying to discover and explore what the crux of the common issues are. It could certainly be mechanical (within the transfer case), but it's just as possible its in the electronics/actuator. The switches and contacts are equally temperature sensitive as they rely on tiny pieces of wire with light pressures that work mechanically.

One thing that would be useful to figure out is if the actuators move at all at startup? I'll see if I can't answer that question as I have my car on stands at the moment.

 

[slowride]

FYI...

It's hard to tell the scale from your pictures, but the motor appears to be a Mabuchi: probably a 540/555 or 380...

They are cheap $5-$7...

If it is a physical mechanical problem...

 

[TeCKis300]

If it helps... enhance

RS-455PB-3050
TD408509

There are cases on Tundras where the rear power connectors break at the right angle contacts. Soldering is the repair in that case.

 

[slowride]

My GUESS would be this is a knock off of the Mabuchi... By the part number pattern and where it is made.

RS-555PC-3550 High Torque

12V - it can handle 9V low to 30V to kick it lose.

1/8" shaft.

These motors are TOUGH and keep working under unbelievable and terrible conditions, but the do take a voltage kick to get them spinning (when compromised)

They are cheap and cannot be serviced ( yes you can spray them clean, a little cleaner than they were before) the brushes are hard & tough.

If your in there doing all the work and can't find the weak link this may be it. You have lots of variables with the old micro switches too.

It sounds though from your post you brought the old components back to life, but so did Dr. Fronkinsteen (LOL).

If these parts got wet and have possible internal (micro level) corrosion...

Well, you are already in there with it torn apart you may want to replace the possibly compromised electricals if it is still not functioning at 100%.

Great thread, I'm learning a lot.

Good Luck on it !!!

 

[cogniz]

INcredible write up, thanks. I just came in from trouble shooting. Bottom of actuator (the HI/LO solenoid I think) was fine. Jumped it on the bench. The top actuator (where the vent tube attaches) had a dead motor. Switch was fine, contacts look fine.
Once I opened it I suspected water damage, as the chromed motor bracket showed a lot of rust. So, I just ordered the Mabuchi RS-555PC-3550 on ebay for $12! Man if that works I owe you a 12 pack....

For the record, it took me 3 attempts to get the gear / contacts aligned properly upon reassembly. I would plug it up, turn the truck on, and check for the 4x4 flash showing the error. 3rd time was the charm. I just opened the top of the housing a little, pick up the gear inside (can't see it) and rotated about 3 degrees. Reassembly and check...

Also, be careful of the o-ring. It will fall out easily upon reassembly. In retrospect I should have replaced it (can-o-seal)...

 

[TeCKis300]

Glad someone else is finding this useful! Let us know how it goes and if there's additional nuggets and hints you can find.

This fix is more applicable than people recognize at the moment. I believe that literally every high mileage cruiser that has a flashing indicator at startup, or inconsistent actuation, is dealing with some spectrum of the electronic contact wear. Rather than the heavy gear hardware within the transfer case.

Take a look at the breather hose that comes in at the top side. The tube has been known to crack over time, or come off, leading to water ingress. Mine looked fine but I put a tie wrap around it just for good measure.

 

[cogniz]

Take a look at the breather hose that comes in at the top side.

Pretty sure that's what happened. It had been two years since I used 4WD and in that time, the breather hose came off letting in water.
I've zip tied it too..great minds.

 

[cogniz]

No love. Got the Mabuchi motor, RS-555PC-3550, and the motor is too big. I've removed the RS455PB3050 and tried to blast the crap out with Contact Cleaner. No love there, either.
Anyone have a lead on the motor? Mine also showed Made In China, TD377x09. I'd guess that's a manufacturer designation by Toyota.
Also, this was helpful trying to decode the motor number Motor Designations and Their Meanings | Products Information | MABUCHI MOTOR CO., LTD.

 

[cogniz]

Also, any ideas how to get the gear off the existing motor? Looks like a micro spring clip perhaps...

 

[TTO5]

I have been without 4 lo in my 2010 lx for about a year. I can flip the switch but here no relay clicking near the glovebox like before it stopped working. I don't get any indicator light either. I have tried starting the truck up with switch in 4 lo like was previously recommended here but nothing gets it to work. Anyone know if it is the actuator would I at least get the relay click and light to come on? I am hoping it is a problem with the switch assembly on the center console and not an actuator