Subject: 2022 Ram 1500 Laramie — Surface Rust on Rear Differential & Axle (Warranty + Fix Advice?)

[Ramanski]

RamForum members,

I have a quick question and would really appreciate your advice.

I own a 2022 Ram 1500 Laramie 4x4 with the 6’4” box, currently with 43,000 km, and it’s still under factory warranty here in Canada (British Columbia).

As you can see from the photos, the only rust on the truck is surface rust on the rear differential and rear axle. The rest of the underside looks very clean. Even the front side of the rear differential looks fine — it’s only the backside (when looking from behind the truck) where the surface rust appears.

Also worth noting:

• The rest of the truck was undercoated when the truck was first delivered in 2022
• According to the Carfax, the first owner requested the dealership to apply undercoating
• The rest of the frame and components still look very good

I had a few questions:

1. Warranty Question

Since my truck is still under factory warranty, would this type of surface rust on the rear differential and axle typically be covered by Ram/Chrysler warranty in Canada?

2. Long-Term Concern

If I leave this alone and do nothing:

• Will this cause problems long-term?
• Can a truck still go 200,000+ km with this type of surface rust?
• Or should this definitely be addressed now?

For context, I live in British Columbia, Canada, where they use occasional salt and sand in winter, but not as heavily as some other provinces.

3. DIY Fix — If Not Covered

If this is not covered, what would you recommend as the best way to fix this properly myself?

4. Proper Process

I’m seeing conflicting advice online. What’s the best approach?

• Should I wire brush / metal brush the surface rust first?
• Should I power wash and clean it first?
• Should I use Rust-Oleum primer + paint?
• Should I use brush-on or spray-on products?

5. Product Recommendations

What do you guys recommend:

• Rust-Oleum primer + paint?
• Black Rust-Oleum paint?
• Rubberized undercoating spray?
• Fluid Film or similar corrosion protection?
• Any specific product that has worked well for you?

Really appreciate any advice, especially from Canadian owners or those in similar climates.

Thanks in advance — much appreciated.

 

[TRK_GANG74]

Surface rust won’t hurt anything. If you have deep pitting rust with flakes and chunks of metal falling off then you have a real problem. You can clean the surface rust off with some appropriate cleaner and paint it if you wish or you could not worry and leave it alone.

 

[coobie]

Do yourself a favor and get Krown rust proofing for your truck.

 

[06 Dodge]

View attachment 582553 RamForum members,

I have a quick question and would really appreciate your advice.

I own a 2022 Ram 1500 Laramie 4x4 with the 6’4” box, currently with 43,000 km, and it’s still under factory warranty here in Canada (British Columbia).

As you can see from the photos, the only rust on the truck is surface rust on the rear differential and rear axle. The rest of the underside looks very clean. Even the front side of the rear differential looks fine — it’s only the backside (when looking from behind the truck) where the surface rust appears.

Also worth noting:

• The rest of the truck was undercoated when the truck was first delivered in 2022
• According to the Carfax, the first owner requested the dealership to apply undercoating
• The rest of the frame and components still look very good

I had a few questions:

1. Warranty Question

Since my truck is still under factory warranty, would this type of surface rust on the rear differential and axle typically be covered by Ram/Chrysler warranty in Canada?

2. Long-Term Concern

If I leave this alone and do nothing:

• Will this cause problems long-term?
• Can a truck still go 200,000+ km with this type of surface rust?
• Or should this definitely be addressed now?

For context, I live in British Columbia, Canada, where they use occasional salt and sand in winter, but not as heavily as some other provinces.

3. DIY Fix — If Not Covered

If this is not covered, what would you recommend as the best way to fix this properly myself?

4. Proper Process

I’m seeing conflicting advice online. What’s the best approach?

• Should I wire brush / metal brush the surface rust first?
• Should I power wash and clean it first?
• Should I use Rust-Oleum primer + paint?
• Should I use brush-on or spray-on products?

5. Product Recommendations

What do you guys recommend:

• Rust-Oleum primer + paint?
• Black Rust-Oleum paint?
• Rubberized undercoating spray?
• Fluid Film or similar corrosion protection?
• Any specific product that has worked well for you?

Really appreciate any advice, especially from Canadian owners or those in similar climates.

Thanks in advance — much appreciated.


View attachment 582554View attachment 582553

I would just wash to rid dirt and grease, then hit it will a high quality metal rust inhibitor then cover with a quality metal paint like Hammerite or Rustoleum

 

[MADDOG]

Krown or POR-15 products will fix that right up. Check with your dealer first on the warranty. If they decline it, then research those two product lines. They have rust inhibitor and encapsulation products that work well.

My experience was with POR-15 on one of my older trucks. I helped a cousin use Krown products on his older truck. Both of us had some surface rust.

I didn't need to brush and remove the rust. All I needed to do was encapsulate the rust then use the finish coat material to seal the metal. Worked like a charm.

POR-15

 

[Burla]

POR15 is great and will coat that, but I doubt that is what you want. Number one that is from your salt roads so NO manu will never warranty that. salt will get behind whatever you cover that with non oily, like rubber paint or rust paint, you would still need to protect the por15 with the fluid film, so bottom line you just don't need that step and can make it worse long term unless you fluid film the por15. See fluid film dyi thread, if you commit to once every two years and wool wax, you wont ever see any rust grow. See trucks with LONG term FF or WW treatments, chat with @Hemi395 ..

 

[Burla]

FF, WW, or por15 will have roughly the same salt protection period perhaps por 15 add a year, but it is paint, so unless you feel like stripping and repainting every 4 years, it isn't the answer. That is why FF and ww is so much more popular on the board. I dig por 15 have painted many of my undercarriages with it, but I'm in saltless nor call.

 

[Grams]

I would advise against any undercoating or oily-treatement (or POR15).

Firstly, it isn’t an issue except for cosmetics…and if you wanted to stop it or treat it…. wash/dry it or scrub-wash or pressure-wash and let it dry…. Then spray it with Rustoleum “Rust Reformer” …which will cause it to appear flat-black…and will prevent further rust for many years. (available in aerosol spray cans from Walmart, Home Depot, or online, less than $10.)

 

[Burla]

Use your YouTube, look at reviews fluid film long term results, like 100's of them. I say wool wax is now preferred is because that is what Corey aka mr fluid film is saying. Both are great, wool wax creeps slower, both are lanolin self healing oil based. Some of those reviews did fluid film on one side, find those great info.

 

[Mlarv5]

Do your self a favor. Wash it then coat I with this Rust Converter. It uses chemical reaction to change the rust to a non problem. Then paint it, and forget about it.

I have used this on just about anything that had rust. My 2014 JKU was really bad underneath, until I did this.

 

[Hagar1]

You could clean it with a wire brush and then paint it orrrr you could just leave it alone and not worry about it. That material will never rust through.

 

[madtrucker2016]

I would just wash to rid dirt and grease, then hit it will a high quality metal rust inhibitor then cover with a quality metal paint like Hammerite or Rustoleum

Power Wash it, Rust inhibitor, and paint it flat black with a good paint brand because you do not want to do it over again

 

[2019RamInSC]

Gee now I have to crawl under my truck to look for surface rust on my differentials....right after I finish removing all the "rubber whiskers" from my tires. The good news is l will be under the truck and get the spare tire also.

 

[commander]

A good rust converter then some Por-15 The stuff is damn near bullet proof! It does not like UV light, but underneath you should be good

JT

 

[Dusty]

View attachment 582553 RamForum members,

I have a quick question and would really appreciate your advice.

I own a 2022 Ram 1500 Laramie 4x4 with the 6’4” box, currently with 43,000 km, and it’s still under factory warranty here in Canada (British Columbia).

As you can see from the photos, the only rust on the truck is surface rust on the rear differential and rear axle. The rest of the underside looks very clean. Even the front side of the rear differential looks fine — it’s only the backside (when looking from behind the truck) where the surface rust appears.

Also worth noting:

• The rest of the truck was undercoated when the truck was first delivered in 2022
• According to the Carfax, the first owner requested the dealership to apply undercoating
• The rest of the frame and components still look very good

I had a few questions:

1. Warranty Question

Since my truck is still under factory warranty, would this type of surface rust on the rear differential and axle typically be covered by Ram/Chrysler warranty in Canada?

2. Long-Term Concern

If I leave this alone and do nothing:

• Will this cause problems long-term?
• Can a truck still go 200,000+ km with this type of surface rust?
• Or should this definitely be addressed now?

For context, I live in British Columbia, Canada, where they use occasional salt and sand in winter, but not as heavily as some other provinces.

3. DIY Fix — If Not Covered

If this is not covered, what would you recommend as the best way to fix this properly myself?

4. Proper Process

I’m seeing conflicting advice online. What’s the best approach?

• Should I wire brush / metal brush the surface rust first?
• Should I power wash and clean it first?
• Should I use Rust-Oleum primer + paint?
• Should I use brush-on or spray-on products?

5. Product Recommendations

What do you guys recommend:

• Rust-Oleum primer + paint?
• Black Rust-Oleum paint?
• Rubberized undercoating spray?
• Fluid Film or similar corrosion protection?
• Any specific product that has worked well for you?

Really appreciate any advice, especially from Canadian owners or those in similar climates.

Thanks in advance — much appreciated.


View attachment 582554View attachment 582553

In all my years I've never seen rust on a differential housing that caused a problem, except for the diff cover.

I'd hit it with a good coat of Rust oleum gloss enamel black.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 150003 miles.

 

[Tominator223]

Tannic acid. Then paint.

 

[PVilefort]

If it really worries you, scrub the differential housing or pressure clean it and paint with black semi-gloss Rustoleum. For that to rust through will take more time than you have left to live. I have seen rear diff housings from the 1920s and left out in a field, not rusted through. The external rust on your differential housing is not covered by your warranty. Until fairly recently the housings were painted just enough so they were not rusty during assembly.