Sound in 4hi

Hello everyone,

I have had my 07 5.7 4x4 tundra with 230k on it for about 6 months now. Really like the truck but am wondering if I have a problem or not. When I switch to 4hi I get an audible sound. Sounds somewhat like what you hear in reverse. Raises and Lowes with speed but not RPM. Does disappear when load is let off for a second or two but comes back right away. No sound when in 2wd. 4wd does engage and so does 4lo. I have not had much luck finding anything that matches my problem. I do see a TSB that was about a needle bearing on drives side and that does seem to match my problem other than it says it only happens when in 2wd. I do believe it is the front differential. I will start with fluid change. Records show it's up to date but I will do it anyways. Wondering what others would go after first? I'm guessing the needle bearing could be going bad and only make sound when 4wd is engaged? Any other suggestions? I appreciate it!

 

Needle bearing replaced with bushing did not fix it unfortunately.

 

I believe the needle bearing is always spinning since it supports the CV axle. The only thing that disconnects between 2WD and 4WD is the transfercase components, the driveshaft, and the differential. If you remove the front driveshaft and engage 4WD and it still makes the noise it's most likely the front differential. To start with I'd change the fluid in the diff, tcase, and grease the driveshaft. My bet is the front differential maybe has a chipped tooth.

 

I did replace the front gear fluid when I did the bushing. I did not see any metal fragments or anything unusual. I know that does not mean a whole lot sometimes. I have also greased the fittings for the joints as well. I will do the transfer case fluid next and then tackle taking off the drive shaft and see what happens. And I guess start looking for someone to rebuild the front differential or replace it.

 

In my experience, you can definitely hear activity in the transfer case when running in 4WD, especially 4Lo. I’m not sure what you’re describing is indicative of a problem. I would change the t-case oil to verify it’s clean and full.

 

Being that it is a chain driven system I kinda thought about this. I have not had a chance to ride or drive another second gen tundra. I did ride in a first gen and have asked someone I work with that has a 2.5 gen and they say it is quite when in 4x4. May make friends with the neighbor down the road that has second gen 4x4 and see.

 

Just an FYI, my 2007 is the noisiest 4x4 I've ever owned. I only use it a few times a year but it's been like that since I purchased it.

 

I hear this noise as well in 4hi. Its a higher pitch whining sound. But I think it's normal.

 

Your pinion has probably angled slightly over time causing a groove in your differential ring gear causing it to whine.
If you aren’t having any operational issues with it Just keep fresh gear oil in there.
If you changed the oil and found no chunks or nasty shavings I would not worry about it.

My 96 Mustang did this after awhile just put a louder exhaust on it and could barely hear the whine anymore.
Never had an issue aside from the noise. More frequent fluid changes kept the whine down some.

 

I appreciate all the response. I may just leave it alone for now. The bushing has definitely removed the play in that cv axle though.

 

While a different Toyota, my old 01 4runner, makes a slightly audible sound (not a noise) just enough with radio off so you can hear the 4wd is on, I believe its very normal, I mean there are extra things moving now, some sounds has to be emitted, assuming all else in the system works as it should. Luck all.