Rear Diff Whine

My rear diff is making some gear whine and was wondering if theres a recommended fluid I could put in there that is heavier than the DINO 90 that's recommended in the manual to quiet it down.

Otherwise, does anyone have a good and used 3.91 rear LSD for 06 double cab that I could buy? I need to get rid of this noise! Driving me crazy!

I'm in Central Florida in case anyone has a rear diff they could sell me.

 

Welcome aboard! Have you tried adding LSD friction modifier to see if that helps the problem?

Myself and plenty others on here have had luck with Lucas 80W-90. It has friction modifier mixed in already.

$37 Lucas Oil 10046 SAE 80W-90 Heavy Duty Gear Oil - 1 Gallon

https://www.amazon.com/gp/product/B000IG5QPK?ie=UTF8

 

Have you tried changing fluid to see if it helps? Sure fluid level is correct? A full synthetic change with the LSD additives would be place to start.

 

So you run this without adding friction modifier? I recently changed my oil from whatever was in it when I bought the truck to Mobil 1 75W-90 with LSD (I have the factory 3.91 LSD rear). Now I'm noticing a crunching/grinding sound sometimes when I accelerate hard from a stop while turning (like at a stoplight, let's say). I am hearing that our Tundras don't like synthetic gear lube, although I have run it in my Land Cruiser and 4Runner for years without complaint. I guess I'll give it a try!

 

Yes, I've drain and filled my rear diff twice with this, no extra modifiers (I have a factory 4.10 LSD). Truck hasn't complained at all -- no whining, grinding, etc.

 

I've used redline full synthetic for years and no issues. Has the friction modifier for LSD in it, so no additional additives needed

 

Just swapped the fluid out with the Lucas 80-90, and still same noise. When pulling the drain plug, there were some accumulated metal shavings. Little bit of thicker sludge in the oil it seemed. But the sound remains.... so i need some help.

I am curious if it could be anything else? It's definitely gear related, as I can hear it when the truck downshifts for example it picks up speed/frequency in noise.

It is most prevalent at 50-60mph, then after 60mph it quiets down.

Not sure if the transfer case or the front diff would be making this whine while it's being driven normally in 2wd.

 

Does the noise disappear when it's in 4WD? If that's the case, it could indicate that the needle bearing on the driver's side of the front differential is worn out.

There's a dedicated thread on that needle bearing and an upgrade for it. Others have reported driveline voodoo that goes away in 4WD... https://www.tundras.com/threads/ecgs-bushing-tool.59664/#post-1563580

Regarding sludge and oil shavings, the drain plug has a magnet on it so stuff accumulating is by design. Here's what mine looked like when I DIY'ed at 150K, dealer had done it previously at 75K.

 

It's in 2wd mode doing the whine. Not 4wd dependent.

 

If you can't recreate the whine while in 4WD then I'd wager it's the needle bearing.

 

Shoot let me give that a try today....standby..

 

Ok... sound is the same in 4wd as it is in 2wd.....

 

Anyone parting a 4wd DC that I could steal a diff off of? This sucks!

 

Does anyone know if this diff carrier from ECGS is an LSD? Doesn’t say it is.

https://eastcoastgearsupply.com/i-788575-tacoma-8-4-non-eld-t100-tundra-3rd.html

for $750 after the core charge if this is a plug and play solution I’m just going to do that.

 

It appears that one item is for them to rebuild yours...I'd call them and ask.

 

Yeah or core charge for +600 but not sure if it’s LSD or not, doesn’t really specify. I’ll call and check

 

There's another thread on here somewhere that describes the different types LSDs, Lockers, eLockers, et al. I didn't really take the time to digest it all because my tiny brain is already pretty full. I only made a mental note for future reference...when my time comes I'll want to replace it with stock.

 

Ok, called them up. For the base $750 price it's basically just an open diff.
Now I need to decide if I want to spend the extra $500 for the TrueTrack upgrade....pretty spendy now.

My ideal would be to find a verified good working order used diff for now! Anyone got any leads on a part out anywhere that would work for me?

 

Did you ask how much/how long to rebuild yours?

 

Yep, $1300 for the local shop to rebuild.

 

I used that Mobil 1 and continued to have the shudder from stop. I added two tubes of friction modifier over 12000 miles. Shudder from stop started again 2500after the second change. Recently changed to amsoil fluid. So far it’s been great, but quite spendy. I tow a ton though so probably a harsher use case than most.

 

I though double cabs all had the 3.91 gears? Maybe I’m mistaken

 

he’s got that O4. Insert unicorn emoji

 

I was testing you…… hahah thanks

 

no worries, I made the opposite mistake in another thread thinking they all had 4.10’s. But see, I’m learning!

 

And it’s not a wheel bearing?