I am trying to keep my 84 F150 SC alive as long as possible, though the rust will win one day. Anyway, the rear window has been leaking so I picked up a new seal from LMC. These are not too difficult to put in but the new one leaks in a few places and in the lower corners the seal does not cover the recessed area like the original did. This is the greatest area of leaking. Contacted LMC and they said this is what they offer for this application and offered a credit. They don't sound to confident in their product. Now I need another one. From searching it appears that LMC uses precision seals so I don't want to go down that road again. Steele is the best but was hoping not to spend a few hundred bucks. Anyone have good experience with another brand or some how rejuvenating the old one? Trying to stay away from filling the groove with silicone and popping it back in. Things like that seem regrettable in the future.

Thanks

 

I'd check with my local auto glass specialist. They've had every glass solution I've needed. If you have a large city nearby there are usually several to choose from. Fortunately for me I've been able to use the same glass shop for all my autoglass solutions for more decades than I can remember.

 

The glass specialist will most likely tell you they always add sealant with a rubber gasket. Not silicone, but some sort of butyl rubber they use for this purpose. The skill in this is applying it without making a huge mess.

 

I cant remember ATT who made mine but I got a full rubber kit, door seals, vent seals outer glass seal rear glass seal, off ebay.
A bunch of us did after the first person said the fit was great and they were right.
I reused my old seal on the solid glass as I wanted to replace the glass with a slider and wanted to use the new seal with it.

I have heard of others having the same issue of the seal not sealing in the lower corners.
Wonder if Soft Seal makes anything for our trucks?
Dave ----

 

It's a known issue that has been around as long as these trucks have. A lot of the aftermarket sliding rear windows did not fit well at all, and the lower corners was a big problem. CR Lawrence rear windows used to come with "corner extensions", or "flange extensions" that fit on the window frame for the specific purpose of filling in the corners better and pushing the seal/gasket further into the corners. I assume these CRL brand windows still come with the corner extensions? I'm not sure.

My 1984 F150 just had the plain back glass, and even with it, the stock gasket did not fit hose corners 100% perfectly. When I decided to install a SRW, I went with a factory rear slider from a 1996 F150. It was I think $35 at the local junkyard. I cleaned it up and painted the aluminum parts and it fit like a glove. I can't remember when Ford came out with the upgraded rear window and seal, but I believe it was 1994 or 1995. These windows had a bigger thicker seal that fit the window and cab much better than the 1980's versions.



PS: Dave...that full cab gasket and seal kit you're thinking of was I believe Fairchild brand? That's what I used, but I gave the rear window seal away since I installed the 1996 factory slider.

 

We used the Fairchild branded kit. It too, in my case, had a rear glass seal that was "thin" in the lower corners. On first install the "recesses" were visible on the driver's side. I popped the glass back out and with help reinstalled working toward the lower corners. Very subtly pushing the seal material towards the corners instead of stretching it around. Not perfect but the recesses are covered and it doesn't leak.

I have my original seal around here somewhere.

EDIT: I should mention that it was more difficult somehow the way I did it the second time. Faulty memory, but as I recall it was harder to do the second try, even with help. I looked back at my build thread and seems I only mention having help.

 

I think you guys are right on the "Fairchild branded kit", your brain works better than mine
I guess that kit rear seal is like the rest, dost not fit well.
I got lucky that I used my good old seal and not the kit one.
Dave ----

 

Looking this morning, mine seems to have shrunk up a bit. Still way better than the first attempt where you could stab a popsicle stick into the gap. (maybe slight exaggeration)

OP mentioned rust. Of course mine was clean and the body seam adjacent to the corner was smoothed and freshly painted. This seam may be where the leak is coming from.

 

Thanks for the responses. Figured this was an issue for more than just me. The original on this truck with solid rear glass fit well and covered all the corners completely. I think it just gave up after decades of sitting in the sun etc. No pampering for this old dog.

The new seal from LMC/Precision? was crazy tight to get on the glass before install. Been a long time since I did this but I don't recall the seal being so tight to fit to the glass. This tight fit might be contributing to the leaks with in the top and certainly in those tight corners.

Yes the seams were a bit rusty under the old seal, but I did clean those up and put some por15 on there and some seam sealer in hopes of slowing the inevitable. I also resealed the rain gutters as those were also leaking down inside contributing to the rear SC panel rusting out. Not going for show truck here, just be nice if when you hop in the truck in the winter the condensation is not so great it drips off the sunroof on your head.

Not finding a lot of options out there that look better than what I have. Tempting to clean up the old one which came out in one piece and use the butyl sealing in the grooves to seal things up. I am sure I may regret that if I ever need to take it out again though!

I appreciate the input.

Looking at Steele's website they have two listed that fit these rigs. Part #20-0825-81 $195.99 and 200971-81 $112.99. One is almost half the price of the other one. I'll have to call to figure out the difference. Even the cheapest one is three times what the LMC version cost, but if it works that is a time saver from doing this again and gain.

It was mentioned that the later 95-96 may have an improved seal around the window, however, when you search for the seals, most aftermarket places list the same seal from 80-96 and other the same seal from mid 70's to 96.

 

A National Parts Depot rep emailed me back and NPD uses the Precision unit, the same as LMC. The NPD rep said they have no record of poor fitment or returns on these.

 

Steele also replied explaining their two part numbers for the rear window. "Thank you for contacting Steele Rubber. P/N 20-0825-81 can be used for both the sliding rear window and fixed, while P/N 20-0971-81 is used for the fixed window only. If you have any other questions, please feel free to reach out."

Steele seems to have a decent reputaion so I am going to spend the money and see if it fits better.

 

[QUOTE=Rembrant;20747566]It's a known issue that has been around as long as these trucks have. A lot of the aftermarket sliding rear windows did not fit well at all, and the lower corners was a big problem. CR Lawrence rear windows used to come with "corner extensions", or "flange extensions" that fit on the window frame for the specific purpose of filling in the corners better and pushing the seal/gasket further into the corners. I assume these CRL brand windows still come with the corner extensions? I'm not sure.

My 1984 F150 just had the plain back glass, and even with it, the stock gasket did not fit hose corners 100% perfectly. When I decided to install a SRW, I went with a factory rear slider from a 1996 F150. It was I think $35 at the local junkyard. I cleaned it up and painted the aluminum parts and it fit like a glove. I can't remember when Ford came out with the upgraded rear window and seal, but I believe it was 1994 or 1995. These windows had a bigger thicker seal that fit the window and cab much better than the 1980's versions.



I think the rear seal for the slider is more robust than the fixed glass version. It's also 1/2 shorter in diameter from what I can tell. Steeles website shows there being actual molded corners for the slider version versus the solid glass version being just a continuous loop.

Slider - https://www.steelerubber.com/rear-wi...ket-20-0973-81
Solid - https://www.steelerubber.com/rear-wi...ket-20-0971-81

 

'Morning KraigJ- Im planning to upgrade to a slider. In my case, I am looking at an older slider and gasket (with the lock strip) unsure of the exact year but pre-90's for sure.
So does your picture show the Steele gasket or is it the 1996 Ford gasket that came with the window that you got at the junkyard? It looks to have the lock strip.
Do you remember if the sliding window frame is the same width as your solid glass frame?

Im thinking I might get the older slider and use my original gasket ( with no lock strip)

 

That is not a locking strip like used on the pre 80's trucks it is just a plastic chrome strip that most likely has gone looking bad.
My rear solid glass has the plastic chrome strip and I left it in the rubber before putting it on the glass and then in the truck.
Dave ----

 

Pawnee - Those are not my pics, they are from Rembrant's posting.