Andystoy AT4
Active member
GM part #84225817 is the lower valence (air dam) that is not included on the 2022 AT4 R. It does not fit according to GM parts (the AT4 has 2 brackets that are larger than the ones on the SLT or SLE) but it does fit with a bit of a trim around the two brackets that hold the already in place lower plastic part. The deflector slides over the lower lip of the already in place plastic and is secured by 10 galvanized C clips that GM uses on the inner liners etc. GM calls these nuts #11548580 and the bolts which have an installed washer 11547420 (12 reqd.) 2 bolts (1 on each end) are installed from the top) and the other 10 including the clips are installed from the bottom. I drove my front tires onto some ramps so it was easier to work on.
Clearance to the bottom of the original lower plastic with stock tires was 12" (30.54 cm) and with the lower deflector installed it is reduced by 1.5" to 10.5"(26.7cm). The install is like factory and hopefully provides a reduction in drag and a slight improvement in fuel mileage. I am not concerned that I will damage the lower deflector because I still have 10.5" of clearance and I don't plow ruts that are that deep.
I drove over to the dealership and checked out a SLE that had the air dam installed from the factory so that I was sure I could make it fit before buying. The lower deflector costs about $100 cdn or $60 USD but does not include the nuts and bolts. If you buy the nuts and bolts from GM you pay about the same price for the hardware as the deflector. I bought the bolts from an auto parts store for $0.44 each instead of $5.55 from GM. My suggestion buy the install hardware at an autoparts store even if you use small bolts and washers instead of the GM style C clip. No additional charge for the bugs.
Clearance to the bottom of the original lower plastic with stock tires was 12" (30.54 cm) and with the lower deflector installed it is reduced by 1.5" to 10.5"(26.7cm). The install is like factory and hopefully provides a reduction in drag and a slight improvement in fuel mileage. I am not concerned that I will damage the lower deflector because I still have 10.5" of clearance and I don't plow ruts that are that deep.
I drove over to the dealership and checked out a SLE that had the air dam installed from the factory so that I was sure I could make it fit before buying. The lower deflector costs about $100 cdn or $60 USD but does not include the nuts and bolts. If you buy the nuts and bolts from GM you pay about the same price for the hardware as the deflector. I bought the bolts from an auto parts store for $0.44 each instead of $5.55 from GM. My suggestion buy the install hardware at an autoparts store even if you use small bolts and washers instead of the GM style C clip. No additional charge for the bugs.
