Center diff hot

[Atomic Skull]

Is it normal for the center differential to get hot? I'm talking painful to the touch hot here.

 

[SirCrashALot]

Is it normal for the center differential to get hot? I'm talking painful to the touch hot here.

Have you felt the drive shafts? They can also get hot.
Yes, it is a normal occurrence. When the diff bleeds power to the front is when extreme rpm differences occur and the diff fluid heats up.
That's why most bashers use very thick diff fluid for the center.

 

[Atomic Skull]

Corally recommends 10,000cps for offroad in the center diff but I'm using the factory stock 100,000cps. Car is an Asuga XLR with a Mamba Monster X 8S (on 6s battery) with a 1717 1650kvmotor and a 16T pinion. I was driving around on wet grass with offroad tires. I don't recall the diff heating up that much with street tires on asphalt.

 

[Partydaz]

Oh yeah the one in my Kagama would get crazy hot after a session, was running stock 100k but stuck 500k because the front wheels would bloon like mad and it helped with the heat issue. Still gets hot but not hot to the touch anymore.

 

[SirCrashALot]

Yes. Grass is extremely demanding. Especially with high grip tyres. When you accelerate hard, the rear tyres dig in, causing the car to squad and lift the front, reducing the traction of the front, so the center diffs out.
I ended up using 1mln Cst diff fluid in my Muraco, Asugas and Mojaves. 250K Cst in my Radix.
Keep in mind that i usually run in sand. That's a low grip environment and i like the wheels to all run equal rpm's to prevent the diffs from getting scorching hot.

 

[Horatio]

The shearing action of the silicone diff oil generates the heat. If you use thicker centre oil to save diffing out to the front, you'll find that rather than bleed 'the surplus' power through the front wheels, now the truck will wheelie more and becomes less stable on higher traction sections.

From a racing/lap time perspective, it's generally not preferred. Font grip is lost entirely if the tyres aren't in contact with the track!

'Throttle management' is the key then, as whilst thicker centre diff oil will yield less heat producing viscous diff action, the truck will end up flipping onto its lid more frequently otherwise.