Did the 9.75 axle change from 97 to now? I looked at fords diagrams w/ part numbers. Most part numbers match, few don't. Seems to take the same Limited slip P#4026, but can't convince myself that all are relatively the same. Maybe someone can help?

 

larger axle bearings and shafts in '99 (from a 1.620-inch inner diameter to 1.705 inches), a larger outer pinion bearing (increased from 1.31 x 2.68 inches to 1.31 x 3.00 inches), and the pinion was altered for a longer crush sleeve.

 

Heres another question, is the trac lock diff the same and will a 05 posi fit in a 97 and vice versa?

 

your best bet would be too look at an aftermarket locker website. if they list the same part number for 97-current then the oem should be the same 97-current. Because the axles are a different size im betting the spline count is different as well so i dont think they are interchangable.

 

I did look and found that they are the same part numbers (detriot true trac did). The reason I originally asked was because I found a 9.75 ford racing posi on ebay. It was for a 05. Its too late to get it, but I wanted to know for later applications. Didn't want to get it and not work. I think I might go with an aftermarket. It sounds like people here like the detriot autolock. Going the other way may be a costly technical error. Thanks for your advice.