Troubleshooting Included Bolts Too Big to Install Trailer Hitch on Vehicle

Updated 09/08/2018 | Published 09/07/2018

Products Featured in This Question

Nylon Tube Brush - 1/2"

(534)

$12.69

Curt Trailer Hitch Receiver - Custom Fit - Class I - 1-1/4"

(573)

$178.93

Question:

I just purchased a hitch from you guys and it came with M12 1.25 bolts for mounting to the frame. While attempting to mount the hitch using these bolts, they seem to be to wide. Does my car sometimes use M10 1.25? I feel this would be the correct size? Hoping you can help me through this. Thank you,

asked by: Christopher D

Expert Reply:

The issue you described in your question is actually not too uncommon, especially on vehicles that have seen a few winters. I did verify that the M12 x 1.25 bolts are the correct size for installing the Curt Trailer Hitch # C11265 on your 2015 Toyota Corolla. Since the underside of your vehicle is constantly exposed to dirt, grime, moisture, salt, etc - this gunk can find its way into the open weld nuts or bolt holes on the vehicle where the included hardware for a trailer hitch is attached. This grime hardens over time, causing rust and corrosion that can make the bolts seem too big for the weld nuts when it's time to install a hitch.

What you can do is try spraying the bolt hole with a lubricant like WD-40 and then let it sit for a couple minutes so that it can penetrate and soften the grime. Then scrub the bolt hole with a wire brush like # 814092, rigorously running the brush in and out of the hole. You may need to repeat these steps a few times depending on the amount of build up. This should hopefully clean it out enough to start threading the bolts in.

I have also attached a great article on exactly this subject that you can look through. Please just let me know if you still have problems installing the hitch and I will be happy to look into this further.

expert reply by: Chris R