Inbred thread/someone delete

I had these symptom for a while, and I eventually came up with a theory that over the past year I was able to test and validate.

If you’re lazy like me and don’t rotate your tires then this could be your problem and why Toyota recommends such a regular tire rotation. I hadn’t rotated mine in 15-20k. The uneven wear between the front and rear tires meant that the front and rear were spinning at different rates, a big No-no on our 4wd systems.

I could engage and disengage at a stop, just not when rolling on the road. If I engaged at a dead stop and disengaged on a roll the bang the transfer case would make from being bound up would make you think that a bomb went off in your transfer case. All jokes aside, this kind of loading is terrible for the chain in the transfer case, and the high jolt from the disengagement is bad for any meshing components in the drivetrain.

Anyways, a tire rotation and year later worth of driving— with equal/similar wear on all tires the 4wd operates smooth as butter.

TLDR: Don’t be lazy like me. Rotate your tires every 5k.

 

Same reason you shouldn't engage 4x4 while turning. Wheels moving at different speeds.

 

Glad it works fine but I don't buy your premise. If you never rotate in 50K miles, the front and rear tires in the middle of the tread will have the same circumference, however the edge of the tires will be different.

 

If after 50k or even 20k of unroated miles the centers of your tires all have the same diameter/circumference you have major issues and should do the chalk test to get a more proper tire pressure.

 

So rotating your tires corrected the problem? You verified by creating the noise, then rotated the tires and then couldn't get the noise to happen again? Interesting. Rotation at every oil change it is then.

 

my front tires had maybe half the tread of the rear if not less. The rotation alone didn’t fix it. I had to drive it enough until the rear tires, which are now in the front, wore down enough for the tread to be similar to the other pair.

I do have A/T tires which have chunky tread, as well as a softer compound compared to say highway tires. So the problem is most likely amplified a bit.

I’m not sure if it’s just my Tacoma or it’s common amongst all Tacomas but my front tires wear out at atleast double the rate of the rear. Between the 2.7L not being a power house and not really loading up the rear tires, and all the weight I have in the front(skid plate ,winch, bumper) as well as Tacomas being front heavy to begin with, the fronts wear out exceptionally quick on my truck.

 

It's not tire rotation. The tires on my 3rd gen never get rotated (company truck). Before I got new tires my fronts were more worn than the rear and I never had 4wd issue. Toyota recommends tire rotations frequently just like all the other car brands.

I also had a time in my 2nd gen where my driver front tire had a nail in it on my drive home from a ski trip. When I got home I had 16 psi in the tire. I use 4wd on and off on the way home and had no issues with the 4wd.

On very cold days sub 10 degrees, sometimes the 4wd will take a bit longer to engage and it happens on both my trucks.

The front diff gearset is always spinning, so it really doesn't matter if there is a slight difference in tire diameter. Even a few PSI difference in the tire will affect the diameter slightly and most of us never have exactly the same tire pressure in each tire.

 

Using this logic, if I have say 25k miles on all four tires, and I get a flat on one of them, I would have to buy 4 new tires or my 4WD wouldn't work.

 

Would VSC intervene if this is the case?
Toyota mentions that VSC may intervene if use a small spare.
I don't think 4Hi is "smarter" than VSC. Most likely you have a case of e/actuator issue.

 

OP has an issue with his truck, it's not a tire problem.

 

Not buying your theory and not buying your validation. You only need one confounding variable and your theory is shot. You have multiple...

Surface you were on when disengaging
Speed at which you disengaged
Incline or descent angle you were on when disengaging
etc... etc...

Any of ^ could impact forces on your drive train which could make your front diff actuator have to work extra hard to pop the fork that engages/disengages 4WD. Correlation != causation.

 

Did it make the sound when disengaging 4wd even while going very slowly completely straight, on a surface like dirt?

If you're on a grippy surface and drive even a little off center and introduce bind, when you pop it out of 4wd it'll make a little bang/clunk sound.

 

Not necessarily, if he's been introducing a little bind and disengages 4x4 it will make a sound. That's not a problem with the truck but rather user error

 

You’re over thinking this. It’s the same stretch of highway that is flat and straight. What I’m describing is a mismatch of gear speeds in the transfer case.

 

Your tires aren't the prob.

 

You’re right

 

Sounds like you had either a bad alignment or some defective tires if they wore like that. In the past i've gone 30,000 miles between tire rotations... the tires (bfg a/t's) wore evenly and the 4WD worked flawlessly. Sold that truck (88 4Runner) with around 350,000 miles and the 4WD still worked like new. To avoid the "bang" sound when disengaging briefly take your foot off the gas pedal so there's no load on the drive train.

 

I'm not sure if lack of tire rotation is the problem. But I'll say it is conceivable.

If you're operating in 4X4 it is important to have 4 identical tires and with very nearly the same mileage on them. It doesn't hurt a 2wd, or even a 4wd if only driven in 2wd as long as both tires on the same axle are the same.

By the time most of us replace our tires they are roughly 1 size smaller in diameter than when new. If you were to replace just the 2 on the front axle with new tires and keep the old ones on the rear you are effectively using 2 different tire sizes and that will screw up a 4X4 system. Even if used in slippery conditions.

On a rear-wheel-drive vehicle the fronts always wear out sooner than the rear. If you never rotate, will the fronts wear out enough to enough to cause binding in 4X4. I'm going with a definite maybe.

My son works in electrical construction and always commutes long distances to construction sites. He usually works in one place for months until that project is finished then he moves to another construction site. He drives cheap econobox cars to save on gas. He came to me a couple of years ago with a question. Seems he had been working at the same place for 6 months. It had always been exactly 100 miles round trip every single day. But for the last 2 weeks it was suddenly only 95 miles. He wanted to know what could have happened.

I asked him if he noted the difference after buying new tires, and he confirmed it had. A new set of street tires on a 2010 Nissan Sentra were 5% larger in diameter than the old ones he took off in the same size. You'll see an even bigger difference in a 32-33" All Terrain Tire. And if mis-matched it will cause binding in 4X4.