What happens to the rear diff with age

[Dhan]

The other day I was at a car meet. Mostly Corvettes and Subarus, with the occasional Evo. I got to talking about the DSM with others and someone mentioned the LSD in the rear differential of the DSM is likely not working after 20 years. He explained my car was still transferring power to the rear but not modulating the power, so only one wheel is getting power at any given time.

Is any of that true? What parts are likely expired in your average DSM's rear diff after 20 odd years?

 

[90laserRSfwd]

Unless you somehow lost the fluid in the rear, nothing should be "wrong" with it. Tearing it down (or having someone like Tim Zimmer tear it down), and replacing the bearings / rebuilding it should be all that you'd need.

You can read this link for a more detailed explanation: http://www.syncro.org/VCTest.html

 

[Dhan]

It all makes sense now....the guy at the car meet doesn't know that we have a viscous type LSD, not the clutch type that must be on Evos nowadays.

After reading the link, I see that our LSD is kind of like an automatic's torque converter. And like you said, not much can go wrong, so long as there's fluid.

Thanks for the info!

 

[90laserRSfwd]

It all makes sense now....the guy at the car meet doesn't know that we have a viscous type LSD, not the clutch type that must be on Evos nowadays.

After reading the link, I see that our LSD is kind of like an automatic's torque converter. And like you said, not much can go wrong, so long as there's fluid.

Thanks for the info!

Your welcome.

 

[pauleyman]

It all makes sense now....the guy at the car meet doesn't know that we have a viscous type LSD, not the clutch type that must be on Evos nowadays.

After reading the link, I see that our LSD is kind of like an automatic's torque converter. And like you said, not much can go wrong, so long as there's fluid.

Thanks for the info!

No. Not like a torque coverter. The rear diff gear oil is not inside the viscous coupling. The coupling is sealed and has a fluid all on its own. The viscosity changes as a function of rate of shear which locks up the coupling.