Rear Driveshaft to Differential Bolt Head Size?

[FD7683]

Hello, I was in the process of removing the rear u joint for inspection when I found that supposedly a 14mm nut/bolt combo felt a little loose with my 14mm socket. I put a 13mm on it and didn't fit and eventually I gave up as I didn't want to create a headache. When I put a digital caliper gauge to measure the head size it comes back to a 13.5mm nut/bolt? Hardware seems to be original and there is no severe rust as the grease protects the bolts. Was I safe using a 14mm?

 

[wtfemery]

I don’t know what they should be, but my napkin math says you should try a 17/32” socket if you have one

edit:

actually, i remembered i’ve bought these exact bolts before, since i lost them when i was replacing my driveshaft. I still have the baggie in my car, the part number appears to be 90080-10294 if that helps you in any way

 

[FD7683]

Thank you for the part number I appreciate it! Next time I try to remove it I will use a closed 14mm wrench and break the nut loose. Fortunately in my case the u-joint seem to be in ok shape and have very minimal highway vibration after a good tire balance.

 

[brillo_76]

That is really odd if not rusty. I deal with that a lot but I am in the Rust belt. They are supposed to be 14 mm or OEM are. Maybe someone changed it it with a new nut in the past.

 

[FD7683]

It is the factory bolts. The truck still has a shimmy I really do need to take off the joint for inspection. I should be fine with a 6 point open head wrench I feel like a 12 may strip the nut...

 

[brillo_76]

Good idea with the 6 point. Mostly if you get the rigs off the ground all 4 wheels on jack stands. You mostly can feel bad u joints and see the flexing when the needle bearings are going bad. They will definitely cause a pile of vibration and noise as well.