Lucas 85w-140 Rear Diff Whirling

[Rocketman777]

What is the best Diff Fluid to reduce the whirling noise in a 2007 FJ Cruiser Rear Diff? Any feedback from those using Lucas 85w140 - I have heard good things about it. I've read dino fluid is better suited for this compared to synthetics. Also, would you use a additive such as Lubeguard Limited Slip additive or use the 85-140 as is. Thanks.

 

[FlyNavyP3]

Toyota differentials are generally pretty quiet. Everyone I have ever had that made noise didn't need a different lubricant to fix it it needed bearings. If you plan on keeping the vehicle I would highly recommend instead of trying to mask the noise with a different lubricant that you fix the cause of the noise which is a bad bearing. I have attached a picture of a almost imperceptible differential noise that was confirmed with a used oil analysis and only fixed by replacing parts. This is the lower pinion race out of a Toyota differential.

 

[FlyNavyP3]

Also

 

[zeng]

Yep, pick a high KV40 85W140 in this context.