Stuck in 4hi?

So I'm pretty sure that I didn't notice a high rev sound when I was PCS'ing (military move) from VA to FL back in February. I've been commuting about 20 miles one way each day for work and I have never taken the truck off-road since I've owned it (approximately 2 years).

Symptoms - I just recently I believe I'm hearing a high rev sound coming from the front of the truck. There doesn't seem to be any issues shifting gears starting from 0 mph on up in terms of the automatic transmission. As I accelerate, I don't seem to notice it as much which is probably due to the Flowmaster. With the windows up (because it's quiet), when I let go of the gas at anywhere above 50 mph I can significantly hear a high rev sound, but the transmission is downshifting fine (my rpms are below 2k easy).

Amplifying Info - I'm able to put the truck into 4hi (light blinks then remains solid) and drive without any issues and then go back to 2wd (light blinks then goes out). After switching from 4hi, I'm assuming that I am back in 2wd since the 4wd light goes out.

Questions - Is it still possible that I'm still in 4wd? What other possibilities are there? What are some things that I can do to fix or at least identify my issue? If it is stuck in 4hi, what kind of damage could I have done by continuing to commute in this condition!?

Thanks a lot fellas for all of your help.

Gil

 

jack up one front tire and see if it spins, if it don't then its locked

don't drive on dry pavement or drive train can be damaged with extended use

 

Does it seem louder in 2WD? If it quiets down when you switch to 4HI, it could be the front drivers side CV axle needle bearing. It won't hurt anything driving straight, it will bind on turns on hard pavement. If you have any amount of lift (like a leveling kit) in the front, the needle bearing hums like mud tires, but when locked into 4HI, the sound should go away. Many TW owners have the noisy needle bearing even with stock suspension. I have an '05 TRD Sport with Bilstein 5100's set at .80" in front, and I have this issue.

https://www.tacomaworld.com/threads...differential-bearing-vibration-thread.152173/

 

Well my problem turned out to be the wheel bearings. Just to be clear, there was no play in either wheel and they rotated freely with minimal sound. Firestone didn't figure a wheel bearing due to this. Since I purchased a used 2016 4X4 front axle that everything included from end to end (including the wheel bearings still pressed in hub), I went ahead and tried the wheel bearings first. Problem solved. I guess i have extra CV axles and differential.

 

4hi there is definitely worse things you could be stuck in, am I right?

 

It doesn't take many miles on pavement in 4hi to do serious damage to the transfer case. It ain't a cheap fix.

 

Fortunately, when I had the truck up on jacks I quickly realized that it was not stuck in 4 hi. I then went to thinking wheel bearing or needle bearing or maybe even something internal inside the differential. I replaced the wheel bearing because it was the easiest solution. Once the wheel hub was out it was easy to tell that at least one of wheel bearings was bad and was replaced.

 

A while back my girlfriend drove my truck for close to an hour in 4-hi to pick me up from jail in rural Maine. She just didn't know to disengage 4-hi. This was only like the second time she had ever driven my truck. Didn't seem to do any damage to the truck and I've driven like 10k since this happened. Kind of smelled like clutch tho... but, the was probably her fault and not caused by 4-hi