Tacoma seems to be trying to engage in 4 high while going down highway

My Tacoma seems to be trying to engage in 4 high while going down highway 3.4 automatic transmission anybody have any clue

 

What are the symptoms?

 

Yeah, what makes you think it is engaging?

 

Got to hearing something like growling my son rode in passenger seat and looked under truck while driving down rd four wheel axle start kicking in and out on its on

 

What kind of transfer case is it? Manual shift?

 

A little bit of punctuation would go a long way in helping us understand your issue.

There are a few variables between the transfer case, hubs, and stub shaft actuators. We'll need to pin those down. Lets go over those:

There are two primary types of transfer cases. The J-Shift and push button 4wd selector. The push button 4wd has a button the transfer case shift lever. It does High - N - Low + 4wd Push button. The J-shifter, does not have the button, but rather a little J leg to engage 4wd.

Manual Hubs Vs Automatic Disconnecting Differential- Do you have to get out and manually engage the front two hubs to be in 4wd?

The stub shaft actuators come in electronic form as well as a vacuum operated earlier form. Many folks mistake the breathers on the electronic actuator for the vacuum lines on the vacuum operated version.

With those differences in mind. I'm not sure what you mean for 4 wheel axle shaft. The transfer case is connected to the front diff via a drive shaft. That should only spin if 4wd is engaged. On a ADD truck, the cv axles (from the front diff to the hub) spin 100% of the time whether 4wd is engaged or not. On a manual hub truck, if the CV axles were sometimes spinning, it would indicate an issue with the hub locking / selectors.

 

It’s auto locking hubs not push button selector next to automatic transmission selector in center console and not cv axles turning its the actual front drive shaft from front differential to transfer case

 

If you try to engage 4wd what happens?

 

It doesn’t change anything because it’s already pretty much in 4 wheel drive

 

WTH you talking about

 

It's either in 4wd or it's not. What happens when you intentionally engage 4wd? Does the transfer case and ADD tube engage? Light on the dash go solid, etc...

The reason I am asking this- the 4wd system needs to be used every so often so that it operates properly. If you think something is stuck in limbo, it's possibly that engaging 4wd and getting those parts moving will help it completely disengage.

 

Sounds like a bad switch or bad wiring? Maybe?

 

Not much solid info to go on here.

A growling noise could be a lot of things? And considering the tcase and its front driveshaft are on the drivers side, not much can be seen from passenger side. Based on the information you've given so far it's difficult to understand your conclusion that the problem is related to the 4x4 system.

If you want help in diagnosing what ever it is that is happening to your rig, a lot more detailed info from you will be necessary.

 

Most likely the ADD actuator on front differential.
If the vent hose is broken/disconnected the contacts get fouled up with water mud dirt etc.
Pull the 3 screws on the ADD cover and shine some light on the situation. ESPECIALLY if the hose isn't connected.

 

If you want to isolate the problem.
Jack the truck up, put the transmission in neutral, spin the front tires.
If the front drive shaft turns, you’re looking at an A.D.D problem.

Got to back of truck, spin rear wheels. If front drive shaft turns (and front wheels do NOT turn), look at the transfer case.