Front differential replaced 3X

Front diff has been replaced 3x under warranty. I have plat extended warranty

 

The noise is cause by the failing outboard needle bearing. The needles will slowly disintegrate and the metal will circulate through the diff shortening its life. It won’t result in a catastrophic failure but will do damage as the metal circulates. Because the CV axle is constantly working on the needle bearing in 2WD the axle will start to become sloppy as the needles wear which can cause vibration. Here is a picture of a CV axle damage after 25,000 miles.

 

Yes, and the dealer still denied that there was an issue.

 

My 2019 makes a low hum at about 48 mph on up through 60 mph when the wind noise, etc., drowns it out. Running in 4wd has no effect. Still does it. Been this way for about a year. Currently at 84K. Bushing time?
Thanks,
bc

 

Can be tire.

 

If it doesn’t go away the second you put it into 4wd, it is not the needle bearing

 

OK. Its not the oscillating sound others describe either. The tires are Michelin ATX2. Not their quietest tread. Will use street tread next time. Front wheel bearings are smooth with no play and alignment is within spec.
bc

 

I wonder if not driving 10 miles in 4x4 monthly is the culprit killing these needle bearings?

 

Not related. In 2WD the needle bearing are rotating, I 4WD the needle bearings are stationary on the CV axle shaft, the reason the noise stops in 4WD.

 

Most of the time the noise you’re describing is tire related. Does the noise change when you drive on different road surfaces? Does the noise change when you transition from a concrete bridge surface then back to pavement or from an older paved surface to a new paved surface?

A noisy wheel bearing can still be tight with no play and still make noise. The proper way to diag a wheel bearing is with the truck on a hoist, running up the bearing and listen with a stethoscope for noise.

 

I did not know that ... however my theory is while in 4x4 (for that distance) the needle bearing is getting extra splashed with oil regardless if rotating or not. Anywho, I have the ECGS parts and tools archived on my phone if the noise ever shows up on my truck cause I damn sure not going to drive 10 miles off road in 4x4 monthly.

 

The spider and axle gears would still be rotating in 2WD so that would take care of any lubrication the bearing would need.

Using the 4WD once a month is more to ensure that the diff and transfer case motors are exercised and that the front prop shaft U joints don’t fail.

 

Pavement can make a little difference, (new smooth is better than older rougher). It starts almost like the flip of a switch when you hit the magic speed. Tire pressure high is a bit noisier as well.
bc

 

Then your noise is tire related.

 

It has not become worse since first noticed about 8 months ago. Bearings usually get louder once they start to talk in my experience.
thanks.
bc

 

Run your hands over the tread and feel if they are feather edged and/or stepped. Go one direction with the tire rotation then back the opposite direction and see if the thread catches your hand.

 

The needle bearing assy is pressed into the diff housing, not the carrier. The bearing never rotates. The carrier, which does rotate in 4wd, is held in with taperred roller bearings. The needle bearing only supports the cv.

In 2wd, the spider gear is simply rotating with the left cv. There is a bunch of slop where the spider rides in the carrier (the design flaw) and makes all sorts of noise. Because the needle bearing has too much clearance, it can’t hols on to the rotatin cv. However, in 4wd, the carrier is being driven by the driveshaft and resisted by the two axles/spiders. All of this tension pushes the spiders into the poorly machined carrier and therefore all the banging around/ noise stops. The same concept applies with ring gear. There is a significant backlash between gears, but as long as it is loaded up you hear nothing.

 

Visited my local auto repair shop to inquire about ECSG bushing installation. Shop manager was unfamiliar with the needle bearing prob and was never installed the bushing.

 

Any competent repair shop should be able to install it. It’s pretty easy but make sure to change out the axle seal while they’re are doing it. Use only a Toyota seal.

 

I contacted East Coast Gears directly and asked them if the bearing/bushing is installed in the differential housing or the carrier and this was their response

 

Thanks for clarifying this and addressing my mis-understanding.

 

How is everyone getting 10 miles a month in 4WD? I live in suburbia in the east, so I don't have wide open expanses near by like some of you western folks.

I've not wanted to drive in 4H on pavement, even in a straight line. Would putting the truck up on jack stands all around suffice?

 

I wouldn’t sweat the 10 miles a month in 4WD. Most of the failures are from the actuator motors so as long as you exercise them you won’t have any issues. Just put the truck in 4H then to 4L and back to 4H then back to 2H. Cycle through a few times will work both the transfer case and diff actuators.

 

Western and Northern NYS. This winter 10 miles a month in 4WD is easy !!

 

You don't need to do all 10 miles at once
Try doing 1 mile every other day
If you keep your steering wheel straight
(Like driving on a freeway) you can use 4hi
no problem (It will not harm the drive train)
Just remember to switch between 2hi & 4hi below 60mph
When you switch into 4hi be gentle on the throttle
When you switch out of 4hi to 2hi briefly release the throttle & it will help get back to 2hi

I've been doing the toyoda 4x4 Thang for 13 years....the manual should be more precise on these particulars

Another note about switching into 4hi from dead stop....many times for the 4hi to engage you need to roll forward, but what if you find yourself in a bind & can't go forward?
Best remedy is to put the trany in reverse then quickly switch back to drive
This maneuver generally kicks the 4hi on

 

I put mine in 4H everytime I drive it. My driveway is about 200' long and is gravel. I do it so the driveway doesn't get torn up ( 2 birds 1 stone )