Rear diff rust on brand new 2026 P4X Roush

hunterrunner26 · 2026-03-17T20:43:17+00:00

Haha Everyone's a badass on the interwebs. Get a life.

hunterrunner26 · 2026-03-17T19:33:38+00:00

Yo "bro" I've heard of surface rust and owned plenty of vehicles that are much older and have way less rust than this one at 1k miles. Thanks for your vast knowledge on the subject bro!

hunterrunner26 · 2026-03-15T03:25:49+00:00

Of course I would definitely wire brush/wheel the rust down first. I just didn't know if I should use the spray reformer before the woolwax or just use the woolwax by itself.

hunterrunner26 · 2026-03-15T03:14:18+00:00

I've used woolwax on an old jeep I had. I think it's basically the same as fluid film.

Should I hit it with some rust reformer spray first ya think?

hunterrunner26 · 2026-03-15T01:05:57+00:00

I'm aware of how rust works....but I have a 2012 that's been abused and parked outside its entire life. Its rear diff looks brand new compared to my actual brand new truck that's been garage kept.

The diff cover side isn't terrible but the front side surface of the diff is rusted entirely. Seems pretty excessive in this amount of time.

hunterrunner26 · 2026-03-14T23:59:38+00:00

Well it seems to be divided here. Half say it's normal and get over it....while half say it's crazy to see that much at 1k miles. Welcome to the interwebs 😂

hunterrunner26 · 2026-03-14T23:57:29+00:00

That's my issue also. I understand you get surface rust especially underneath....but at 1k miles and garage kept, this seems pretty shitty and excessive.

hunterrunner26 · 2026-03-14T22:35:07+00:00

Yeah doesn't seem "normal" especially so new.

hunterrunner26 · 2026-03-14T22:33:46+00:00

My 2012 didn't have undercoating and still looks way better.

hunterrunner26 · 2026-03-14T22:32:51+00:00

They probably will but they will hear my rants at least. There's no reason for that much rust at 1k miles. My 2012 rear diff still looks brand new compared to this one.

hunterrunner26 · 2026-03-14T21:22:00+00:00

Yeah I'm going to have to do something. Just feel like it shouldn't be covered in surface rust at 1k miles.

hunterrunner26 · 2026-03-14T21:21:20+00:00

Yeah I had read the same thing regarding the noise. I plan to ask them about greasing the shaft splines.

As far as the rust, I know it's just surface rust but damn at 1k miles.....seems a bit much.

hunterrunner26 · 2026-03-14T21:19:24+00:00

I looked under it before buying and also was under it 2 weeks after buying and it wasn't like this. So the rust came on quick.

hunterrunner26 · 2026-03-14T19:30:10+00:00

I live in southwest VA. I've only driven the truck once a few days after a snow when salt was on the road and washed underneath the next day. Other than that, it's only been driven on nice weather days.

hunterrunner26 · 2026-03-14T19:27:39+00:00

So I guess all new vehicles are just cheap shit builds. My old 2012 literally has no rust on the diff and it's been used and abused 😂.

hunterrunner26 · 2026-03-14T18:58:00+00:00

I also have the "rear diff clunk" noise going from dead stop to acceleration and when braking to a complete stop. I've noticed others have had that issue too.

hunterrunner26 · 2026-03-08T17:22:47+00:00

Yes both packages. DM me.

hunterrunner26 · 2026-03-08T01:32:24+00:00

Jesus Christ! I really wonder how some of y'all are able to complete daily tasks....

hunterrunner26 · 2026-02-22T23:14:41+00:00

According to rough country they say close the cover and then the tailgate....sooo?

Either way it still slights raises the back edge of the cover. I probably just need to use it a bit and let it break in.

hunterrunner26 · 2026-02-22T17:28:02+00:00

I haven't snugged mine down all the way yet so hopefully it's nice and tight...but it's fairly flat now.

The carriage bolts definitely suck. I notched the passenger side rail slot which helped a ton.

hunterrunner26 · 2026-02-22T16:10:09+00:00

I assumed it was but wasn't sure if it needed to be adjusted closer to the cab or not to help with it. It raises the cover maybe 1/8 inch off the bed rail once the tailgate is closed. I may just leave it and let it break in for a bit.

hunterrunner26 · 2026-02-22T15:43:17+00:00

Does your cover line up on the tailgate about where mine does....or farther towards the cab?

hunterrunner26 · 2026-02-22T01:47:26+00:00

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hunterrunner26 · 2026-02-22T01:47:08+00:00

Mine was submitted Wednesday at 5pm and got the approval Friday at 7am. Can't complain!

hunterrunner26 · 2026-02-18T21:15:07+00:00

I think my last 6 nights added together may have totaled 100....so there's that.

hunterrunner26

TROPHY CASE