4x4 Won't Engage - Brand New Tacoma - Looking for answers - Please Help

Having experienced this first hand with tread life and different tread patterns, the people who say its not the tread have no idea what they are talking about.

The difference in tire size due to wear and even different tread patterns can cause the 4x4 to have trouble both engaging and disengaging.

EDIT: How the heck did OP pay $44k for an offload when everyone else is getting them for around $35-40k. OP should be more pissed that he was ripped off

 

Couldn't you just put the truck on a lift and then see if 4wd works? I'd tell the dealer to show me it working with the tires removed from the equation just to verify their diagnosis.

Maybe the dealer is right, but it seems like it would be easy to test and verify.

 

Late to the party but here's my $.02:

It is not uncommon to have this happen and it is not specific to Toyota.

I've experienced it over the years depending on how much wear the remaining tires have.

Edited to add:

techpage.jsp

 

Ya that could work. I worked with a master tech and basically 4wd would only engage at low speeds and within the first couple few feet of turning it on, if it didn't work immediately we stopped and would reverse and typically during the reverse everything would align and click in.

 

@The hammer ...... Great advice..!!!!!!!!!!!!!!!

OP it sounds like you are getting nowhere with this dealership. Take your business elsewhere. Just remember, the dealership is not the Toyota corporation. They just sell and service Toyota products. They are an independent entity. I would try dealing directly with the Toyota corporation.

I had no problem at all with repairs when my 4-wheel drive system was stuck in 4-High. As I stated in an earlier post, the actuator and two forks in the transfer case had to be replaced. I was very pleased with the warranty service performed on my truck. Neither the lift nor larger tires came into question.

I am very happy with my truck. It is a great vehicle. Companies provide warranties because every so often something will happen like this.

Good luck, and hopefully you can get this taken care of soon.

 

I've actually engaged my 4Hi when tires are slipping. Old or new, it should engage as I doubt my traction control knows the 4/32nd difference in thread depth. However, I have replaced my fluids with synthetic which seemed to have aided in easier 4x4 engagement. I suggest you simply replace your T-case fluid to synthetic before buying new tires. Also helps to turn the steering wheel just a little bit left or right for 4x4 engagement.

 

Worst case is you need to replace two tires, not all 4. A difference between front and back wouldn't matter for sure, just side to side. Though I think that's baloney myself.

 

It will still matter. There is a reason you need the same gearing in the front and rear diff, different wheel sizes front and rear is the same concept. The ECU and 4x4 module is 100% monitoring each wheels speed to make sure they are within range, if not tension could build in the drive line due to mismatched speeds.

Edit: Another link: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=18

 

I think it would only matter if there's a significant enough difference between the tires because I'm pretty sure there has to be a minimum and maximum variations before the system even picks it up.

 

It’s your actuator. It needs to be replaced. Did you go in deep water recently? Maybe mud? The actuator housing is made out of crap plastic. It sometimes gets water in the seal and rust the connectors. Go underneath and try banging on it.

I had to do it with my gen 2. Banged on it and worked temporarily. Finally had to replace it myself.

Still same crap actuator on these gen 3s. Hopefully that works

 

Attached excerpt from manual.

 

The transfer case delivers power to the front and rear axles via a chain...no? as far as I know...should be more than 2.38mm of slack in that. The dealer is just doing process of elimination at the owners expense which could be construed as a material breach of his performance contract i.e. warranty between the owner and Toyota.

 

The chain does not have an infinite 2mm of slack lol. Once the initial rotation takes up the slack you now have tension on the driveline.

 

Yeah but I can’t get my 4WD to engage unless I back off the throttle a bit...under throttle it just won’t engage until I back off.

 

Stop calling it a $44k truck!

 

That’s pretty normal. Ever float gears in a manual transmission? You need to let off the gas to take the pressure off the gears before it will change gear. Similar concept with the transfer case and ADD.

Neutral throttle it should engage just fine (aka no acceleration)

 

If you guys are interested here is a video that goes over how our entire 4x4 system works in great detail.

https://youtu.be/47m7QAPrpsI

 

Hey, crazy situation and I feel for you.

Perhaps suggest to the dealer that you would pay to have them swap 4 tires on rims from a truck in inventory to have them stand behind their diagnosis without you having to fork out for new tires needlessly.

In my time at the dealer we did this for vibration / driveline issues now and again to support and assist the customer.... thats YOU.

The dealer is there and exists to service you.

Overall a sad and shitty story.....

 

Big White is a genius with this system. OP you should take him up on his offer to help. And have you or the dealership lifted the truck and engaged 4wd? That seems like it would answer the tread debate

 

It may be able to lock faster but will still cause tension. Since the ECU is most likely programmed to avoid tension it won’t shift if the speed differential is too large.