How To Trouble Shoot 4x4 Actuator

Side note on this -- the yellow grease in the transfer & front diff actuators looks kind of stiff & hard compared to the average drivetrain grease you find on splines, in bearings, etc. What's the deal with it? Is it that way from the factory or does it dry out a lot over time? When I looked at mine at 63K miles on a 2014 Taco it was quite stiff -- maybe as stiff as refrigerated butter -- but still slick enough to be "greasy".

What is the "OEM" grease used in there, and what are suitable replacements?

 

White lithium grease will be fine but if you want the oem here it is, warning it’s not cheap. Toyota calls it body grease.

 

White lithium

Edit: see @6 gearT444E already replied. I did not use OEM grease on the ones I helped rebuild. Just cleaned the old stuff out before adding new

 

Didnt happen to bend them side to side by accident? The male pins in the actuator case are ok?

I kinda doubt either of those are the issue, but never know.

 

Male pins were okay. Thank you for the suggestion and also recommending to check the ground! Figured out the issue.

Thank you for helping me troubleshoot @Dm93!!! 4wd Hi and Lo are operational again to include shifting back to 2wd. The issue was a bad/loose ground (at EE, EE1, and ED). This is my friend's truck; looks like someone removed the harness previously and forgot to tighten down the bolts. The other issue was that I didn't seat the final gear all the way down to the t-case spline. Looks like the gears jumped and caused the limit switches to miss align.

 

Nice, glad you got it working again and no parts required

 

Hey guys, believe my front add is out as well.

Auto trans 2001 4wd.

when I hit my 4wd button I hear the transfer case engage, but get no green light at all.

Is this a sign it’s my front diff actuator? I mean it’s a good sign if I hear at least one motor working right? Lol.

 

I'm not really familiar with the systems on 1st gen trucks but looking at the wiring diagrams they appear to operate in a similar fashion to the 2nd gen, I found a pin voltage chart for the ECU and a wiring diagram if that helps you.
Based on what I see it could also be a problem with the 4wd Detection Switch on the transfer case or related wiring.
Also have you checked if the vent hoses on the actuators are connected and not cracked?

 

I think I have to take this on this weekend. What are folks using as gasket/sealer between the Actuator and the Diff, and also for the plastic cover? thanks

 

Rtv. The cover has an o ring.

 

Thanks! any particular flavor of RTV?

 

I used the high temp red stuff from autozone

 

FYI, it was the 4WD sensor. I did the Actuator solder, but still had intermittent 4wd. replaced the sensor and it shifts right into 4wd.

In my case, I would turn the switch to 4hi and most of the time it would blink w/o engaging the ADD. TCase would shift OK. Some times, usually going >20mph, it would shift into 4hi, but mostly blink.

So, if you have intermittent 4wd, I'd start with the sensor. 10 min and $10. only need a 27mm (1 1/16") socket.

 

I'm finding part # 84222-35090 online. Is that what you ended up replacing?

 

This is the one I got.

$19 Beck/Arnley 201-1788 Back-Up Switch

https://www.amazon.com/dp/B001KSCYCI?ref=ppx_yo2ov_dt_b_product_details

EDIT: Its the sensor closer to the front of the vehicle. I had to remove the plugs to the TC and both sensors to get access. Use a standard depth socket, there's not a ton of room up there, but more than enough (its not a struggle, but theres not much extra space).

 

There was an entire river inside of mine…

 

Well, at least you know what the problem is! Sucks....

 

It's somewhat relieving.

I cleaned and soldered it for now since the motor was still working. Looking for the best price on a new OEM unit.

 

Amazing that motor still works!

 

Decided to tackle the ADD over the past couple days. What a massive waste of time that was. I don't think messing with the ADD is a good first move for everyone. Obviously some here it was th issue but I believe it could be in other areas. Doing the propr electrical checks will likely narrow it down but I will follow up on that.

Symptoms: 4WD indicator lamp flashes. Will not shift into any of the modes whilst vehicle is on. Like many others, if you shut down the vehicle, move the selector switch, then turn the vehicle on, the 4wd must read the current status and you can hear it audibly engage (or disengage) when you turn on the truck and it'll show if it's in 4H or 4L with no flashing. However, going back to 2WD shows it flashing whether the truck is on or you power off and select 2WD.

After reading 42 bloody pages, I'm pretty sure it's a sensor and not mechanical for me though it could be the rear actuator so I won't rule it out. Being in the desert water doesn't accumulate though I've been through some puddles and creeks of decent depth but never submerged.

Removal of front actuator (ADD): just drop the two diff brackets with 22mm socket. Use a large wrenchnon top of some grips to keep the nut from spinning. Comes out easily with an impact. This drops your diff enough to comfortably reach that tricky back left bolt. I sued a 3/8 wrench to break it then 3/8 e-wrench with a 12mm socket and wobble adapter to wizz it off. Removed the wobble adapter for the other three bolts to pull them. If you don't undo the bracket you can still reach that back bolt with a 3/8 and standard socket but it's slow hand numbing increments. A 1/4 wrench with flex handle would likely be better (and comfortable. ) I didn't have one. I used a second jack to lift the diff brackets when reinserting the large bolts... this makes it straight before tightening the brackets back on for reassembly.

Actuator housing... use a Philips 1, make sure it's fully seated deeply and it'll unscrew fine otherwise you risk camming it out. My first attempt was a #2 and slightly did damage before switching. Upon reassembly that particular screw got a little more cammed while tightening. I didn't time the gear correctly (only one position) because it dropped on me on reassmbly but I had assumed it dropped in the same direction when putting cover... on turns out it wasn't so I had to pull it all off my truck again. So if you reassemble the unit hook it up dangling from your wiring harness to test before bolting it all back up and cursing that you had to redo it. Anyways, 4 screws were okay the fifth I had to extract and since I'm not taking it apart again I just put it back in mostly tight surprisingly. But worst case scenario it can be tapped out again. 4 tight bolts should be plenty to hold it anyways

Onto the ADD: clean as a whistle. I was surprised. I'm at 200k miles by the way. There was yellow grease I removed but still globs of white grease some under the contact pins and on the contacts so I wiped those off (still thin layer) and applied it all over the 4 gears in there so it's even and lubed. I went ahead and soldered the motor even though there was tight contact and I bench tested from the outside contacts at the motor and the harness pins. It worked fine. Of course this did not fix my issue at all but now I know. Looking at the ADD socket numbering left to right (not sure this is official numbering) pin 1 and 2 I applied power to move motor and reversed polarity to move back. When fork is in 2WD position the pins 4 and 6 were continuous, I don't recall the ohms. Pretty low like .04. When in 4WD pins 3, 4, and 5 were continuous. Also low ohm reading which makes sense pins 3 and 4 read a little higher (.1) than 4 and 5 (.04) and I think 3 and 5 were in the middle(.06). Not sure that matters unless the ecu needs an exact voltage.

Lots of good sources for electrical posted page 40 and beyond and some pdf way back that I'll use that checklist today at the ECU.

I have a feeling it's my hi lo sensors or wiring. We know it can physically shift and sense it when in 4Hi and Lo after restarting the car. So somewhere from going to 4 hi to 2 hi and vice versa is the issue. If I weren't busy I'd trouble shoot it more but that'll have to come in the next few weeks I'm not terribly worried since this has been going on for over a year.

It could be in the other transfer motor Actuator but I won't pop that off yet. I'll check the ecu first since that's easy and may help trouble shoot. I won't have time to check the other motor anyways for a few weeks.

That's my input if it helps anyone. 2007 Tacoma SR5 V6 5 speed automatic yada yada. 200k miles on the clock.

Edit: it may be in my ADD after all or wiring.