Sealant/Caulk Recommendation June 28, 2025, 07:27:37 am On a recent trip to the Sierra, I noticed this splitting of the sealing caulk that seals the overhang of the house to the top of the cab. Please recommend to me the best product for this repair. Thank you all in advance.(What looks like a crack in the top of the windshield is actually just a cob web.)
Re: Sealant/Caulk Recommendation Reply #1 – June 28, 2025, 07:33:07 am I would investigate and try to determine why it’s cracking. I would particularly look for any water intrusion in the cab over area. It could just be failing sealant, or it could be a sign of larger issues. If it’s just sealant, a polyurethane caulk like PL window and door should do the trick. Rich
Re: Sealant/Caulk Recommendation Reply #2 – June 28, 2025, 11:58:52 am Hi Ray. Maybe it’s something about the 2017 models but my MB has experienced that as well. Mine had it on both sides. The photos below show what I saw when I flew back to Florida in 2020 to inspect and purchase Nocona. It caused quite a bit of concern, and I almost didn’t buy it. I ended up sending photos to Todd at the LD factory to run it by him. He said it shouldn’t be a major concern, just the paint cracking from the stresses of the cabover moving up and down going down the road which really helped in the decision process to pull the trigger or not. It’s mostly visual and shouldn’t affect sealing, unless you see obvious damage to the sealant.So, what I ended up doing was carefully scraping the loose debris and cleaning the area with alcohol, then touching it up with Ford white touch-up paint. It’s held up remarkably well. I do inspect it yearly to see how it’s holding up and so far so good! 2 Likes
Re: Sealant/Caulk Recommendation Reply #3 – June 28, 2025, 12:12:37 pm Thank you Rich and Hill -- Yes, it is not very concerning to me as I do realize that the joint flex a lot due to temperature fluctuations as well as road rocking. The rig is a 2017, so minor cracks are to be expected. I am confident that there has not been any water intrusion because it is under the cab-over far enough that rain won't penetrate, and we have not driven it in any rain since it developed.
Re: Sealant/Caulk Recommendation Reply #4 – June 29, 2025, 12:12:51 am After inspecting 200 or more LDs over the years, I have never seen this issue.I suspect the connection between the front of the cabover is separating from the top of the metal cab. This connection is made with either sheet metal screws or nuts and bolts, depending on the year.To inspect, remove the curtain and the track, and pull the carpet back as shown in the link below to expose the connection. Good chance you will find broken screw heads, if so, install twice as many new screws, leaving the broken screws alone. If broken screws are found, remove the carpet the entire distance arond the cab and look for other broken screws. Add extra screws as you go. 1/4' diameter bolts, washers and locknuts can be used in some cabs.Overhead attachment screws | Three originals screws (one is … | FlickrMy goto adhesive/sealant is 3M 5200 Fast Cure.Larry 1 Likes
Re: Sealant/Caulk Recommendation Reply #5 – July 06, 2025, 08:17:20 pm Quote from: HiLola - June 28, 2025, 11:58:52 amMaybe it’s something about the 2017 models but my MB has experienced that as well. Mine had it on both sides. Same issue on my 2017 MB. I guess I'll be doing what HILOLA and Larry W suggested.
Re: Sealant/Caulk Recommendation Reply #6 – July 07, 2025, 07:38:01 am Yes, I will also inspect as Larry suggested. I'll report back. Thank you all for such detail advice.
Topic: Sealant/Caulk Recommendation (Read 339 times)
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Topic: Sealant/Caulk Recommendation (Read 339 times)
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