hey guys, i have a 77 ford truck with a 9 in rear end and ive replaced the oil seal on the rear end "just the seal" but i need the torque spec on the pinion nut, i heard or read some where that the pinion nut should be torque'd to 75 to 80 ft lbs but im not sure. The last time i did a seal change was on my last 9in rear end and i ended up tightening that pinion nut without torque'in it to spec and the gears juss clunked and i ended up messin it up so i ended up swaping it to my current diff but i dont wanna mess up this one also. I read on another site that it should torque'd to 175 ft lbs but there refering to a whole rebuilt and mine is just a seal change. Any help i would be very appreciated!!!

 

The correct procedure to re-torquing the nut is to measure the bearing pre-load before you take it apart, and then tighten the nut to the point where the pre-load is the same. When I replaced my pinion seal, I punched marks on the nut and pinion shaft before I took it apart, and then turned the nut back to the same position when I re-assembled. At worst, the nut could be one turn too loose or too tight, but that would be pretty obvious.