Differential/transfer case Washer?

[FzeeJ]

Anyone know which one of these washers is for the differential and which one is for the transfer case? Thanks

 

[FzeeJ]

I ordered 2 sets of hex replacements bolts from Wits End and one pack had 1 style washer and the other pack had the other style. I ordered 1 pack for transfer case and 1 pack for differential. Just didn’t know which one was for which. Thanks

 

[ppc]

Transfer case will use the aluminum washer.

 

[FzeeJ]

Found it… Ribbed one is for differential, flat one is for transfer case according to pictures on Wits End website.

 

[Kernal]

Alumimum for aluminum, steel for steel.