Front Differential Needle Bearing Failure: Related to Fluid Change?

I have owned my Tacoma for about two years and this will be my first post here. For reference, the truck is a 2014 Access Cab with the 4.0 and 6MT. I bought it used at 41K miles and it now has just under 64K miles. The truck was purchased with 265/75 AT tires; it now has 245/75 Defenders. The truck is otherwise completely stock. Since it had an incomplete service history when I bought it, the drivetrain fluids were changed at 42K at the dealer. I changed the fluids again at 61K miles with quality brands available locally: Schaeffer’s

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 in both front and rear diffs.

Over the weekend, it developed the dreaded rumble/vibration consistent with the needle bearing in the front differential at highway speed. I checked today and there is quite a bit of play on the drivers CV at the diff. I can move the axle up/down and left/right at the differential case.

Because this has happened relatively soon after a differential fluid change (about 3K miles) is the failure of the bearing directly related to the weight or brand of oil? Has any connection been made to these failures and use of a different oil than the factory fill? Or is it just bad luck?

 

No. It just happened. That is kinda low mileage, but, regardless, it sounds like it needs to be replaced with the ECGS bushing. I'm sure your diff lube is probably fine, but I used Valvoline

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 when I did the ECGS bushing and no issues 15 months later. You'll have to replace diff lube when you do the ECGS, but I'm sure any reputable 75W-90 is fine for the front diff.

 

To be sure it’s the bearing, does the vibe go away in 4hi?

 

I have not done the 4-HI test yet. I had enough time to inspect/grease the rear driveline and inspect the front CV axle.

The vibration occurs at 45MPH and up. Is there any harm in engaging 4-HI at that speed on dry pavement?

 

I would chalk it up as coincidence. I also wouldn't consider 3k miles after changing the oil to be close enough in use to be suspect.

 

You're fine as long as you drive straight

 

One more question to ease my mind: When I did the last fluid change, I started with 5 quarts of

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 and finished with 1/3 bottle or less for both diffs. I swear I filled both until fluid ran out the fill opening, but I am now doubting my work. Could an under-filled front differential cause this bearing to fail?

 

I think it's 3 for the rear and just under 2 for the front. Since there will be residual oil in there no matter how long you drain it, I think you're good. You did it on flat ground?

 

My needle bearing and driver's hub both went bad right around 60K and simultaneously. ECGS for the new needle bearing and there's a memeber on here that does the hubs for a good price if it isnt under warranty still.

 

Modern oils and grease (chemistry) are so good. Just stay within OEM spec and purchase from a reputable vendor. I started buying Costco motor oil and have no regrets.

 

I just ran around the block to do the 4-HI test. Results are inconclusive as the truck had to be warm for me to hear/feel the issue. There may be a difference there, but I need a longer drive to get more heat in the truck.

And yes - the diffs were refilled on level ground with all four tires on pavement.

 

Get under the truck and grab the axle on the end that goes into the front diff and see if it has play in it. Shake it and see if it moves at all.

 

Thanks for the reply. I can move the end of the drivers CV axle up/down and fore/aft at the differential. The play is rather noticeable, I.E. it is more than a few thousandths. I am pretty convinced that I have the needle bearing problem.

 

I would say you have a needle bearing issue. I replaced mine at around 72k. After the ECGS bushing problem solved. Mine had the same play at the diff you are describing.

 

It’s normal to have some play where the cv meets the diff ...
https://www.tacomaworld.com/threads/is-this-cv-axle-play-normal.46338/. Compare it to the other side. ECGS still sounds probable but I wouldn’t use cv play as the deciding factor. I’d shoot for the 4 hi test again.

 

You sure the front suspension is stock? Play in the CV shaft is fairly common in even fairly new trucks, but usually doesn't cause vibration at stock height because the CV shaft sits level (negligible side forces on the bearing).

Cold vs warmup shouldn't have any effect on the front diff because it isn't transmitting power in 2WD.

 

I believe the suspension is all stock. The truck is an SR5 (no TRD packages) and I don’t see any spacers in the front struts. Here are some quick measurements from a relatively level driveway to the bottom of the over-fender, right at the centerline of each wheel:

LF: 33 78”
LR: 36”
RF: 34”
RR: 36 1/2”

Again, these are with a 245/75 Defender tire. Is this in the ballpark for a stock SR5?

 

Yeah unfortunately these trucks have a few weak points and that’s one of them. On the plus side it’s a pretty easy and inexpensive fix.