Troubleshooting Weld Nuts On 2012 Lexus RX 350 Stripping Bolts Of Curt Trailer Hitch Receiver C13143

Updated 05/13/2021 | Published 05/11/2021

Question:

I have a 2012 Lexus RX350 with the factory tow prep package. I bought the Curt class III C13143 hitch from you and it fits in position perfectly. The issue Im having is that the bolts supplied work fine in the two rearmost weld nuts on each side the ones that had the tow loops, but will not screw into the third weld nut on either side, even with spraying the weld nuts with WD-40 and using a nylon tube brush on them. One bolt is stripping out and I have not forced the other one. Is there a possibility that the third weld nut is a coarser thread or slightly different size? Should I just drench it with WD-40 and force it as far in as I can? Your recommendation? Thanks for your help.

asked by: Richard B

Expert Reply:

I would be happy to help.

Based on the issue you are describing it sounds like there is quite a bit of gunk in the weld nuts on your 2012 Lexus RX 350.

I do not recommend trying to force the bolts in, and instead recommend using a M12x1.25 tap in the weld nuts to clean them up. You can pick one up for a local auto parts store, but you will want to be careful to not cross thread the weld nut.

I included a video of the # C13143 being installed for you to take a look at.

expert reply by: Samuel C