2019 Tundra grinding noise only when accelerating in four wheel drive

I have a 2019 Tundra TRD SR-5 with 12" Bulletproof Suspension lift, 40" tires and 5.29 Nitro Gears.
After the lift and tires but before the gear install, I was towing my 7,000# travel trailer in four wheel drive and started to hear a grinding noise (sounds just like a spun bearing) only when accelerating, I put the truck back in 2/wd and the noise stops. Without the trailer, this noise continues any time I am in four wheel and accelerating over 20 mph, when I let my foot off the gas it stops. I took the truck to Toyota and the said the front diff gears were bad, I bought the 5.29 Nitro Gears and had them installed yesterday, the noise is still there. Any suggestions???

 

Update: I have now also replaced my transfer case and front U joints and the noise continues. Next I will be removing the hubs to check the wheel bearings.

 

Check the front diff mounts and brackets carefully. I had this symptom with a broken diff mount bracket bolt, another member had a stripped bolt for his diff drop kit cause it too.

 

Sounds like you need this https://eastcoastgearsupply.com/i-1...amshell-bushingeliminates-needle-bearing.html

 

Good luck

 

@landphil
Thank you for the suggestion,
I just checked the diff mount bolts and brackets real quickly and nothing looked obviously loose or broken but that sounds promising so I'll get under it tonight with a torque wrench and check all the bolts for torque. I'll update after.

 

You have a bearing going out or gone in the front diff.

If it happens when 4wd is engaged it is likely the passenger side carrier bearing.

The bearings in the front diff aren't known for being robust and their lifespan seems to be dramatically shortened with lifts. The higher the lift the shorter the life span.

Four Wheel Drive Operation (4WD) - YouTube

for a 12" lift and 40" tires the east coast gear supply bushing is a fantastic upgrade.

 

Suspension looks highly modified. Premature breakages and problems like this will unfortunately be a way of life.

 

This grinding noise you are hearing is likely from the front driveshaft binding due to operating at an extreme angle. My 13” lifted Tundra does the same thing, grinding from the front when in 4x4 at over 25 mph. Started immediately after I installed the Bulletproof lift 5 years ago.

 

Note to self…Say No to 12” or higher lifts!

 

Just a funny…hope you get you’re problem fixed quickly without much or any cost!

 

FIFY

 

Bahahahaha…

 

This, most likely the outer T-case bearing on the passenger side. When I was shopping for my Tundra I came across two that had this problem, both had big lifts on them. Hard pass.

 

I drove the truck for 6 months after the lift install with no noise at all. After the noise started, I've changed the U joints, regeared both Diffs, replaced the T case, replaced wheel bearings/ hub assembly and it made no difference in the sound.

 

Sounds likely but like said, I've changed the T case and the sound didn't change at all.
The amount of fun this truck is offroad more than makes up for the trouble shooting minor issues along the way. Every issue that's found along the way gets replaced with an upgraded part so it just makes her that much better.

 

I think he meant the bearings in the front diff.

 

Definitely say YES, just be prepared to put more in to it than just the lift.
Go BIG, it's what pulls the little 4" lifted trucks out of the mud so they can go home! Haha

 

I replaced them during the regear and the sound hasn't changed at all.

 

exploded view of an ADD diff. This is from a tacoma but the Tundra is similar if not identical.

exploded diagram of front diff? | Tacoma World

If this happens in 4wd only then the likely culprit is the carrier bearings 41331 B&G in diagram. The carrier is idle during 2wd. The other bearings are spinning on the inner stub shaft, and outer wheel shaft, as well as drivers side shaft.

 

Ok then the only other culprit is the u-joint angle as ViktorG pointed out.

 

That crossed my mind as well but I drove at that angle for 6 months before the noise started and I changed the u joints after the noise started and didn't get any change in the noise. I might tare back in to it this weekend and check that 41331 bearing. thank you for the diagram.

 

Nah, too much grinding while in 4 wheel drive to pull any 4” lifted truck out of mud! Lol

 

Update: I added an additional U joint to the driveline as suggested by Bulletproof (the lift manufacturer) and the problem is gone.

 

Happy to to hear it! Sucks you had to replace so much through trial and error, but at least you know those parts on your truck are solid now!

 

What did you order for this? Link?

 

My guess is you put

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90 in the front diff.