Undercarriage Input

ChunkyTuna · May 19, 2026

Greetings!

Truck is a 2005 that was run in PA. Paint looks good, and the interior is clean, but (Other than that ridiculous spare.), is there anything that jumps out as a concern in these photos? Some rust is expected. But I don’t want to be replacing everything.

Thanks!

Marky Dissod · May 19, 2026

1st pic, upper left hand corner, looks like a frame-to-body bushing bolt, may wanna check on that.
Your leaves and your spare wheel look like the rustiest things to check on.
If the spare is over 6 years old, may want to replace it with a younger tire.

ChunkyTuna · May 19, 2026

Thanks. I would definitely change the spare and wheel. I’m one of those weirdos that still do a five tire rotation. .

So that bolt should be like the one in the fourth photo, with a bushing underneath, correct?

Marky Dissod · May 19, 2026

ChunkyTuna said:
I'd definitely change the spare and wheel. I’m one of those weirdos that still do a five tire rotation.

Wish I'd the patience to be that weird, a 5-tire rotation is likely the wiser way to go.
I normally only use spare when 'NEEDED', otherwise I leave spare alone and rotate the other 4 every oil change / 3000 miles.
When it's time to replace a pair or quartet of tires, I keep the best of those as my new-ish spare.

ORVietVet · May 19, 2026

ChunkyTuna said:
Thanks. I would definitely change the spare and wheel. I’m one of those weirdos that still do a five tire rotation. .

So that bolt should be like the one in the fourth photo, with a bushing underneath, correct?

Yea, like @Marky Dissod said, that bushing looks funky. May need to just replace all the bed mount bushings. Get some heat ready for the procedure or at least spray penetrant on the bolts 2-3 times a day for a few days before you do the work.

stutaeng · May 19, 2026

No personal experience dealing with northern trucks, but seeing Eric O at SMA, I'd ray that truck looks remarkable for being a 2005 in PA. It's similar to NY state, right?

The 3-5 year old trucks that he works on daily are already rusted to hell...SMH

SK101 · May 19, 2026

how do you do a 5 tire rotation with a mismatched rim?

Marky Dissod · May 19, 2026

SK101 said:
how do you do a 5 tire rotation with a mismatched rim?

Rim/Wheel size is irrelevant, so long as the tires' radius/diameter/circumference are all equal.
ECM & TCM & 'posi' treat all the following tires as identical:
265/75R16 - 31.64"
265/70R17 - 31.60"
265/65R18 - 31.56"
(tire wear notwithstanding, minuscule differences can be mitigated by adjusting tire pressures)

ChunkyTuna · May 19, 2026

SK101 said:
how do you do a 5 tire rotation with a mismatched rim?

I don’t yet. I may purchase this one. Would get a rim and tire to match.

Tonimus · May 20, 2026

Welcome! Underside looks fine, sans that body mount already mentioned. Looks solid under there.

AuroraGirl · May 22, 2026

gm put steel wheels under the truck for the spare to prevent cosmetic damage to the wheel and also because alloy/aluminum tend to get corroded bead seats esp with road salts. so they dont hold air.

you can use whatever you want, just consider a shield or taking extra steps to preserve the wheels appearance and remeber to rotate it in the pattern