What Size Tap Can Be Used to Clean Weld Nuts to Install Hitch on 2004 Toyota Sienna

Updated 10/21/2020 | Published 10/17/2020

Question:

I need the thread pitch of the weld nuts and bolt hole where you install the trailer hitch. They are not rusted just dirty and u-haul would not install it so I want to get a tap to clean them out real good before I go for it. Also the the size of the stock bolts would help too. Thanks for your help!

asked by: Mark C

Expert Reply:

I checked with one of my tech contacts over at Curt and he says you're going to need an M12 x 1.25 tap in order to clean out the bolt holes on your 2004 Toyota Sienna; you can also use some PB Blaster and a wire brush to clean out the weld nuts. You will want to be careful when starting the process so as not to strip out the weld nuts when getting them started.

For reference, the bolts used to install the Curt # C12065 are M12 x 1.25 Grade 8 bolts that are 40 cm long.

expert reply by: Erik B