I am upgrading to the 4.2L lower supercharger pulley. Below is a picture of my existing pulley on the left and the 4.2 pulley on the right. The mating surface for the crank seal is a larger diameter on the 4.2L pulley. I don't recall seeing anything about that. Is there a different crank seal I need to get? Is this the wrong pulley?

 

You might just need a 4.2 front crankshaft seal? As long as the outside diameter of a 4.0 vs a 4.2 front crankshaft seal is the same, that should work just fine.

 

I think the balancer I got may have come from a Range Rover. It looks like the timing covers are different.


Range Rover

X308 XJR

 

I have an 08’ XFR harmonic balancer on my stock 4.0 timing cover. I think you just need a 4.2 front seal in your 4.0 timing cover. Don’t forget the very small diameter o ring inside the balancer as well.

 

Thanks I’ll order one. Do you remember having to swap that over when you made the change?