Thanks,
The yoke o.d. and old seal o.d mike the same as listed for the 15557 but the old seal width mikes @ 0.590. SKF lists the width as 0.313, probably won't matter since I'll need a speedi-Sleeve anyway.
Dave, You're right on the spider gears. I pulled the rear cover off and if I hold the ring gear there is hardly any perceptible play in the pinion. Even without holding the ring gear there is not as much play as I thought. The pinion moves less than the amount of one spline before you see movement in the wheel. So I'll probably install the seal and refill with fresh lube.