Rear Driveshaft Cap Bolt Size
 

I have a 2000 F-350 Crew cab SD 4X4 with a 7.3 and I developed a vibration in the rear of the truck. I went to take the drive shaft out and and check the u joint. I can't find a wrench or socket to fit the bolts on the rear axle yoke. 5/16" is to big 9/32" is to small 8mm is to big and 7mm is to small. What the heck kind of stupid size did Ford use? Or do you have to go to Ford for a special tool. Any help would be appreciated.

Double post

Sounds like you need a 19/64s I would guess. I haven't done my superduty, but the last Ford I pulled a driveshaft on had 13mm bolts.

The bolts at the Pinion are 8mm. You'll need a 6 point box end wrench to get them off. I tried a 12point 8mm box end and just rounded off the points on the wrench. Had to go to sears and got the only 6 point box end they had.

Nevermind, didn't read carefully.

Doesn't sound right, how about a pic?

I would hope the OP got it fixed by now considering this thread is over 2 1/2 years old...