Rock Sliders and Sill Rust

specops1526

Well-known member
Jan 17, 2007
845
11
Los Angeles, CA
I'm sure this has been covered in the past but couldn't find what I was looking for with a search.

Recently bought an '03 DII and it has Trek Outfitter sliders installed. Haven't had sliders on my DIIs before. In my quest to "restore" and clean up this truck, I removed the sliders because I spotted a hole on the underside of the Driver side sill while inspecting the underside of the truck.

Well, to my surprise and dismay, that small hole was much bigger and worse than I expected. Driver side sill is much, much worse than the Passenger side.

I suspect I'll have to replace the Driver sill at least.

I have no welding experience so I'll need to have a body shop do this. What's the best method to replace the sill?

Anyone have experience with products like this? https://www.ebay.com/itm/LAND-ROVER-DISCOVERY-2-DOOR-SILL-REPAIRS-/141410764131

It looks like the sills were prepped with some sort of rust preventative coating but it clearly didn't work. When I reinstall the sliders, how do I prevent this problem in the future?

Pics of Driver side:
Pics of Passender side:
Looks like the channel on the sliders collected a ton of water, mud and sand and caused a seam to expand and break.
 

specops1526

Well-known member
Jan 17, 2007
845
11
Los Angeles, CA
Chassis isn't actually too bad in comparison to others I've seen. Definitely a lot of surface rust that I'm planning on cleaning and treating. The rear section has two small spots that aren't great. I think I can clean them up or get them repaired if I'm being really anal. Luckily I'm in Southern California so I won't be dealing with rust anymore. This was mainly a Midwest truck before I bought it.

I think the Sill was so bad because of the Sliders trapping shit.
 

Lake_Bueller

Well-known member
Aug 11, 2004
2,105
59
56
Beloit, WI
My 99 TReK had worse than that (from what I can tell). The PO replaced the sills with replacement parts from Rovers North.

I would agree that the problem is most likely caused by water/salt/silt/etc being trapped between the sliders and the sill. The replacement sill on my TReK are sealed with POR-15. I have yet to reinstall the sliders. But I'm thinking that the rust inhibiitor should be helpful.
 

specops1526

Well-known member
Jan 17, 2007
845
11
Los Angeles, CA
Ah, interesting. Any idea what the parts were on the RN site?

Yeah, if anything I'll paint on rust inhibitor and maybe use the Eastwood interior frame spray.

I'd hate to have to take the sliders off every year to clean and inspect. 12 nuts and bolts per side is a pain.
 

Gordo

Well-known member
I went through this with a D1 for my sons first truck, a little father son project! What I did was cut out the rust and the entire bottom of the sill and anywhere the rust was. I then used box steel (I had to weld some 3/16 I believe to make the box the right width). I then jacked it into place. I used some 3/16 box for sliders. Cut a slit in them to bend them a bit to fit and once I was happy we’re they sat I welded them to the box. Tack in place then pull it out weld it up paint it and jack it back and weld to the old sills. Strong as hell and will never bend. Wasn’t that bad and was pretty cheap. Wouldn’t be that hard to cut it up and do the prep work if you got a grinder and some basic tools and of course a buddy that welds. Just an option. I found this idea on a UK board wasn’t mine. 2DE8F401-2C55-4BEA-8A5C-17FECF740CDE.jpegC2B22284-34F4-450D-B1B2-4A49AF536396.jpeg9C1EADD3-412E-4594-8FB9-364DE6244A1E.jpegA2C5750F-AE21-43CF-A491-7B70D6E4F937.jpeg
 
Last edited:
Aug 20, 2007
2,727
45
Nashville TN
I just got done replacing the floor in the passenger side of my RRC that was fully rusted out. I replaced probably 5 sq feet of metal. Yours doesn't look bad. If the rust hasn't gone up and over into the floor boards, or up under the pillars, it should be a simple cut out and patch weld job, then have them grind it smooth.

If it's only the section in your photo, I don't think a full sill replacement is necessary. it's all spot welded together so removal of the metal that holds to door seals at the bottom there is quick as well if you need to get where the sill turns into the floor. I'd find a few body shops and get some quotes. just leave the sliders off until then. if you don't do it before the winter, I'd definitely treat it with some ospho or sand it down and do a proper prep POR15 job to stop the rust and keep it from getting worse. It will get worse if you don't convert the rust.

You could also have them do a patch job now and a full sill replacement later if you just want the most offending parts taken care of for now.


IMG_1606.jpgIMG_1946.jpg
 

specops1526

Well-known member
Jan 17, 2007
845
11
Los Angeles, CA
Correct, it's just the outer face and under side of the sill. The inside wall looks clean with no damage that I can see. I also don't see it going up into the floorboards. It really happened in the areas where the sliders came into contact with the sill on the outside face or where junk got stuck between the slider and under side of sill.

I just bought both outer sill replacement parts from Paddock Spares that Lake_Bueller linked to. It looks like the shop will need to cut the top off of them so they can just weld on the outer and under side parts.

I did bring it to my shop and they said the passenger side doesn't look bad enough to replace since there is only a small hole on the underside. I'll have them asses again if I have them do the work, hence me buying both replacement sides just in case.

I'll certainly treat both sides with an interior and exterior rust inhibitor before reattaching the sliders.

Wonder if it's worth using some sort of foam or rubber weather resistant material between the sills and the slider mounting points to make a tight fit and keep water and muck out?