Beware factory mud flap installation instructions incorrect

GMCBUD · February 10, 2014

I just purchased a 2014 GMC SLT and it didn't come with factory mud flaps. so I purchased a set from my local GMC dealer. following the instructions I drilled two 9mm holes for the knurled nutserts only to find out that 9mm is about .8mm too large so now I have 2 9mm holes in my fender that don't retain the top two mounting points (nutserts) for my front mud flaps. I tried contacting GMC using their customer service website, only to be told that I must have done something wrong and they recommend that only qualified service techs install mud flaps. I'm posting here to let some other unsuspecting new owner know about this problem to save them the same aggravation! It seems like some customer service people from GM are following this site so maybe GM will actually look at the instructions and correct them. Needless to say I'm upset that I have 2 oversized holes in my new truck that are not holding my mud flaps on.!

02SierraZ71 · February 10, 2014

I have installed the exact same mudflaps on my truck.

The NUTSERT holes are slightly bigger on purpose.

Nutsert are inserted in the hole, and them crimped to a tight fit. similar to a rivet.

You need a special tool to crimp the nutserts, although if you research online you can make an

intallation tool from a bolt and 2 nuts and maybe a washer.

good luck!

mjw930 · February 10, 2014

I just installed the Chevy version and yes, it looks like the holes are a bit oversized but when you crimp the rivnut it captures it just fine.

Be forewarned, the bolt, nut and washer home made tools posted all over the Internet DO NOT WORK. The supplied rivnut's are steel and the home made tools only work correctly with aluminum rivnut's.

Either purchase or rent the proper tool or see if your dealer can install the rivnut's for you. Or, simply bag the rivnut's and use a sheet metal screw, it will hold just fine.

This tool works well for the price. http://www.amazon.com/gp/product/B004KLVJAA/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1