Ford 8.8 Differential Acceptable Spider Gear Play

Good day gents,

I'm getting ready to rebuild my 8.8 differential with new bearings and seals all over. The pinion and ring gear seem to be in pretty nice condition. There was some slop in the spider gears...and I don't know how to describe it other than the two drive gears can move up and down a little bit on the cross pin. Does that make sense? Is this normal? I don't see any measurement specs in the factory service manual.

the most important point that i look for is wear. any irregular wear or galling to be specific. generally speaking the spiders are along for the ride unless one wheel is spinning more than the other excessively. if you put ew tight clutches in then that should not be the case. now if you plan on saturday evening donut championships being the norm you may be adding additional stress
p.s. give us the when and where. this should be good!

Never having owned nor been into an 8.8" rear I don't have any thing to go on. That being said, the MGB Spicer and a GM 10 bolt similar to the 8.8" had dished thrust washers on the spider gears. I seem to remember they had a bronze face in the "cup" that the back of the spider gears rode on. Maybe these (if used) need replacing?

The side gears on non-limited slip units also have thrust washers and since the side and spider gears are bevel gears, a change in either washer thickness from wear will increase the amount of clearance and play.

Yes sir, the 8.8 diff has those same cup/dished washers behind the drive gears within the spider gears. Maybe I'll see if I can find them by themselves.