4wd Light flashes but does not engage

I am having issues getting the 4wd to fully engage on my 2008 DCLB TRD Sport. I replaced the front diff actuator last night and the flashing light went away but now when I turn the knob the 4wd light starts to flash but it never stops I have tried nuetral, moving very slow, going around 25ish, and nothing has worked. If I turn the knob to 4lo it has a buzzer and it still flashes. Does anyone know what this may be?? I am sure the actuator is working now because the light has started to do waht its supposed to as opposed to just flashing all the time like it was(no matter what mode the knob was in) Any help would be great Thanks

 

You can't go into 4lo without getting into 4hi first. So, you have to atleast get it into 4hi first.

Have you checked to make sure you have vacuum?

You replaced the actuator, but did you check the internals of the diff that the actuator is moving to engage 4WD? (side gear assembly?)

 

I have taken the entire diff assbly apart and there were no issues at all with the other internals. I replaced the carrier a few months ago and the actuator quit for some odd reason while it was out of the truck. So it has been without 4x4 until last night but when I got it all together the thing sounds like it is try to work but just does not get all the way there. Is there were no issues with the assbly before why would there be one now? I am also not sure about the vaccum lines, there is a rubber line coming off the drivers side of the actuator but it looks as thought it goes to a vent next to the axle vent in the engine compartment. Any other ideas are very welcome, as I would love to say I have 4x4 again?? Thank for the quick replies.

 

Easiest thing to do is to figure out what is not engaging. Lift the front up turn dial to 4wd, then start rotating driver side front wheel until front locks then center should lock. If front never locks its your front actuator, if front locks but center does not then its your center actuator. If they all lock but light still flashes its one of the two position switches in either front or center actuator.
BTW. When you installed actuator into the front did you re aligned ?

 

I am not sure waht you are asking so I am going to say no. What do I need to do to realign it? Maybe that is my issue? Thanks!

 

There very well may be something else wrong, but I thought I'd throw this out there. You mentioned every speed you tried, but did you only try engaging 4Hi on a straight stretch of road? Sometimes you have to turn the steering to get the front wheels to turn at different rates to align things for it to engage. I've had that trouble before. I can travel a huge distance in a straight line but it won't engage until I actually make a turn.

 

x2 This is good advice. Turning the steering wheel left or right while moving until everything aligns, and then it should engage.

EDIT: Have you rechecked the wiring harness?

 

Time for an FJ T-case

 

I just went out and tried the turning thing and no love. I would like to know what kind of alignment I need to try?? I will also try the jacking it up thing when I get home. Any other ideas??
Also can I get some more feedback on the vaccum lines?? The only line I found is the vent tube line off the actuator? Thanks again!

 

wierd.

everytime i do work on a part that involves a wire..i disconnect my battery. i'm an idiot when it comes to car electronics..but you dont suppose you need to disconnect the battery to "reset" anything do you? (just punting here)

 

On the actuator, there should be a vacuum line.

While sitting in your driveway, engine running, in Park (or ebrake) for safety...
Turn the dial to 4WD. Light is blinking.... Crawl under the truck and pull the vacuum line off the actuator. I would think it should be pretty easy to pull off and put back on).

I'm not sure how much vacuum there should be...but you should feel some sort of sucking at the end of that vacuum line.

If you get vacuum to the end of that line - I would tend to believe the problem lies after that point (actuator, inside the diff, etc.). If you don't have any vacuum at the end of the line - then you probably have a leak somewhere. Follow the hose to where ever it goes....look for anything. Vaccum can leak very easy even with a hairline crack or hoses/clamps not tight enough. If you have vacuum there, it is enough. If its too weak...then you stil have a leak.

You mentioned you had everything torn apart - are you sure everything is put back properly and seated properly?

 

I will try the battery disconnect tonight to see if that is it. Maybe its that simple?

 

janster's reply is much smarter

hell, i'd piss on the sparkplugs if someone told me it would help.

 

Me too , I just want my 4 wheel drive back, is that too much to ask?? We are supposed to get snow again (which I have been sidelined for the past several snows) this week. I love driving in the snow but need my 4x4 to do so confidently

 

I did the carrier a few months ago. Thats when we took the front diff out of the truck. when we replaced the carrier and put it all back in the truck, we took it off the lift to have the light flashing at us as soon as it was started. Then we check the T-case to make sure it was engaging the front d-shaft, after checking that (which was good) we checked the front actuator. I got the new actuator in Monday and put it in last night. The flashing light was gone as soon as I started the truck after the install. BUT then the 4x4 would not fully engage, it just keeps flashing. The only line I found on the actuator is about 6 inches long and goes to a small line, which I thought was a vent tube after tracking it. Maybe when we put the whole diff back in the lines got swapped and now I dont have vaccum hooked up?? where exactly does the vaccum line go to from the actuator? This may help me determine if I have it in the right place. Thanks!!

 

I am having some issues understanding the vaccum line thing. I have just got off the phone with East Coast Gear Supply and he is under the same impression. The hose coming off of the actuator is for a vent tube (located on the drivers side fender well in the engine bay) the actuator is completely electrical as far as I can find, please help me understand this??

Also just took the battery off and reset, with no change.

 

Never mind, I see you have an automatic from your profile.

If you browse to https://techinfo.toyota.com/ you can pay for, login, and search for the documentation for your year and model truck.

The document you're searching for is titled: VF2BM TRANSFER: TOUCH SELECT 2-4 AND HIGH-LOW SYSTEM: INSPECTION (2008 Tacoma)

 

That's exactly what I was thinking. However, in doing some quick searching...it appears the earlier 1st gens were vacuum and the later 1st gens were electric. ???? But I've yet to find concrete information on either!!

sloppyjoe - do you have any pictures of the actuator?

Wait...you're a 2008 right? Your 'drivetrain' should be under warrantee for atleast 5 years/60K miles. I would contact your local dealer and see if this falls under the 'drivetrain' portion of your warrantee. I would think it should be....

 

I went back to my shop last night and took the front end apart again. It appears the used actuator I picked up is not functioning either. I guess thats what I get for trying to be cheap. I will buy a new one from Toyota now and be done with it. Many thanks for all the replies, you all have been great help! And I can confirm there is no vacuum line on the 2008 I have at least. the only hose off of the actuator is for a small vent, the other side has the electrical plug on it. Thanks again I will report back when I have the new one installed.