Testing ADD and transfer case actuator

Ok so I drive my truck and running fine... then turn it on on day and then I see 4wd and 4LO lights blinking on me. I go here on the forum and see the famous ADD fix. I pull off the front diff actuator and see conections are good and nothing is in the black box. no water no corrosion no rust. clean as a whistle. I say ok well I'll solder the motor and the switch maybe its something I cant see. install it and re hook it up.. still blinking at me. So before I test my transfer case actuator how do I test them period?

also how bad is test the transfer case actuator? can you take off the black box like the front diff? or test it on the truck directly?

I have also put it on jack stands and while in 4wd the front drive shaft does not spin... which is why I think its the transfer case actuator? Please help

Thanks,

 

Anyone? I need to know how bad opening the transfer case actuator is?

 

Link in the FSM had you use the heater relay and measure contact resistances. You shouldn't have to remove it but probably wouldn't be a bad idea. My guess is maybe the transfer case shift rail is stuck

 

Whats a FSM?

 

Service manual from ToMoCo

 

Where is that ? Is that on here?

 

OP, two things. The front ADD actuator has a TSB now. It looks like a part change but I have not been able to figure out yet what is different. It had a bit of a reputation for taking in water but you said that yours was ok.

The actuator in the transfer case has had the same problem on occasion. There was a part number changed on it in 2008. Its a mega expensive actuator and generally the transfer case must be removed to replace it. What a number of guys have done is take off the actuator's housing cover, cleaned it up, and tried to free it up mechanically. The transfer case actuator has become a use-it-or-lose-it deal. Apparently the grease goes to hard goo especially if some water gets in there.

Obviously check the easy stuff first such as corroded terminals an broken wires.

Once in a while the 4WD switch itself on the dash goes bad. Also the 4WD computer above the glove compartment is in mix but I have yet to read of one that has gone bad.

If I get a minute today I will come back with an edit and give you some links on this general problem.

EDIT: This is directly from a post I did on another forum. Something in these links should help you:

* Check out Post No. 4 at this link: http://www.tacomaworld.com/forum/2nd...ot-engage.html

Please ignore all those other comments in that thread about those lines being vacuum lines. We have already established that they are not. They are vent hoses and vent hoses only.

* Here is a good thread about the problem you and others have had and some good diagnosis: * Another thread; got a hammer? Check out Post 10. The rest of the thread is informative too: * Clean out the front ADD actuator. See this thread and especially Posts 18-24 by tacosupreme: * Thread about general problems and failures with the front ADD actuator, transfer actuator, confirmed replacement of front ADD actuator fixing the problem and other fixes: http://www.expeditionportal.com/foru...p/t-90151.html

Good luck, and please keep us posted as to what you find so others can benefit.

 

Did you get it figured out??

 

Keeping my eyes on this for later. For some reason, work doesn't seem to want to pay me to take care of my truck.

 

Thanks for this info. My '06 has been getting stuck in 4Hi, with the light flashing, and sometimes both 4 hi and lo flashing. The scan shows no codes. The mechanic at the dealership tells me the transfer case actuator is the issue, showing corrosion. They tapped it with a hammer and it disengaged. It is a $1500 part, so I am hesitant to pay that without trying to clean it up a bit? Any guidance on this? I see someone opened their up. Not knowing how involved this is, has anyone else? A DIY with pics would help but I am not finding one.