I’m starting the cab portion of my restoration and I am going to have a lot of questions. My first question is a take or toss question so I’m not holding on to garbage I have no room for.

My truck originally had a solid rear window. I replaced it with a slider from Performance Centers of America, I’m not sure of the brand, but it was in the late 80s. I then moved the slider to a newer cab during a cab swap in the early 90s. The new cab had no rust around the slider when I installed it. The truck was used and stored outside for about eight years. It was then taken off the road and stored indoors for the next 25 years. At some point in the last 25 years rust holes started to form in four spots along the bottom of the window.

So my question is, is this window to blame for the leaks, or was it just the window seal? Does this slider look like it’s worth saving? I don’t think I’ve seen any posts about rebuilding a slider. I probably wouldn’t be asking this question but new sliders are close to five hundred bucks. Yikes! I know I’ll be into it for all new window seals.

Also, in the top left corner of the window opening, the sheet metal panels don’t come close to lining up. There’s about a 1/4” difference, leaving quite a lip for the gasket to seal around. Is this going to be an issue? If so, how do you fix it?

 

That looks like a universal slider?

As long as you seal at least the top and sides of the seal, from the outside, you shouldn't be getting water in, I'd think.

 

I definitely didn’t add any extra sealant. I only read about a product that flows in and seals it on this forum a year or two ago. I probably reused what ever widow gasket looked the best.

I can see the bottom corners rotting where the water tried to get out at the seem. But the rot holes where the slider meets the fixed glass makes me think that the widow itself was leaking? I wasn’t planning on buying a new slider, but there’s been a whole bunch of things I didn’t plan on.

 

Make sure you don't have any holes in the surrounding frame of the slider unit.

 

Could be that was one or more leaks up high like near the seams at the top corners let in more rain / snow water than the recesses at the bottom seams could release, and some water made it near the center, but I see what you mean by the rust under center of sliding glass panels.

Mine has a factory install slider, and it has drain holes in the bottom of the glass channels but the holes are where any draining would be out side the cab metal. My painter buddy did work on the cap there in 2022, but I had sometime earlier injected a rubbery like black sealant (urethane base I think) at the top outer corners near the cab seams and across the top between using tubes with pointy caps to stop water entry between glass seal rubber and cab metal.

I "semi permanently shut" my slider a dozen or more years ago after it leaked at a car wash getting my Wife & I wet, but I silicone-sealed the leak areas and added a single 1/8" pop rivet at 4 places to keep the sliders shut, then I removed the plastic latch. I had not used the slider after selling the bed cap anyway, in the '90s I guess. I could have just used 2 prop sticks in the channel. I have a new metal latch and I can revert it back to operational if I decide to, and I might yet since I decommissioned my trucks AC.

 

Huge.

Even without a step, the recess will allow water in. With 1/4" offset, the stream will grow to a river.

 

Mine is a no option Custom. No AC or slider. I gotta have at least one creature comfort

Probably if I left the fixed window in, I wouldn’t have any rot? Why does life have so many trade offs.

It’s odd that they put a vent hole at the top. I don’t know how this is useful? I guess they all have this hole?

 

Mine is a "Custom" too, was also with no AC until 1986 when I did it. So I just "undid it" not long ago .... but I have great venting now.

Odd vent hole, but with that 1/4" cab seam "step out", I suspect it would still leak sitting out there on a rainy night even with a solid glass. Hole might have been a PO's method to run a CB radio antenna coax or XM sat radio antenna lead?

 

Was that a bug on the rear window? BROTHER!

id keep the slider, repair the rot, and definitely use a new seal with some 3m “strip caulk” for the small gaps/seams the seal doesn’t quite seal on.

it’s probably just debris build up and a bad seal that caused the rot. Sitting for that long with no cleaning if the seams were starting to go already would definitely cause problems.

 

Yes it is. LU#400. 37 years. It’s been a good run!

One job had a stack of the caution stickers for their dumpsters. So I thought it would only be fitting to put one on my truck. Plus it had the undertones of “Touch my truck and I’ll break you fingers” lol. They’ve been on the truck so long that it’s part of the truck now, so I plan on getting new stickers when I’m done.

Part of me thinks it doesn’t matter how tight the seal is because hopefully it will be garage kept and I don’t plan on abusing it like I used to. But I do plan on washing it, so there’s that. Maybe I’ll clean the slider best I can and see if it can hold water while it’s out. If it looks good while it’s out, reinstall it as best I can. If it leaks at that point, I can change it when my bank account recovers from the hemorrhaging it’s taking. If all goes well, I’ll be looking for something to keep me busy in a few years.

 

Fix the holes, use a new soft still rubber, add sealant there at top left and across to top right, even down the sides, between the rubber and fixed metal ..... and clean up that whole slider. To add that urethane, tape the metal of the cab to limit mess ... use a pointy cap on the tube of sealant to insert the stuff in between the rubber and metal under it .... after cure, trim excess urethane at seal edge & remove tape. It should be OK.

 

I thought I was going to be asking about the condition of the original cab mounts a week ago, but when I saw light through some holes, I figured I was going to need new ones. Plus there’s rust in between the cab and mount that just can’t be cleaned without separating the two. I ordered the two piece OE style because I think it will let water drain compared to the one piece design.

They came in today, and boy am I disappointed. I held the one side up and it doesn’t come close to lining up. When the bottom follows the contour of the floor, there’s a giant gap at the fire wall seam and the angle. If I hold it so it sits tight at the firewall seam, there’s still a giant gap on the angle, plus it doesn’t sit tight and follow the contour of the floor.

Is this normal, and a seasoned body and fender guy would just work their magic? That’s why they make the big bucks. Or is this unacceptable and I should send it back? To me this is unacceptable for American made with original tooling.

The other thing is that it didn’t come with the holes for the body mounts? I looked at the web site, and sure enough there are no holes. It never dawned on me that I would have to drill my own holes. I took measurements to the original hole, now there’s no hole. WTF! I don’t want to chance taking the other mount off yet, because I measured to it.

I also ordered floor pans, even though they’re not horrible. I’ll probably only cut out a small part.

so what’s everyone’s thoughts?






Crooked along the firewall seem when following the contour.

 

This is turning into a whole other project. Most of the questions I had I could find in the back pages. Plus I had been watching a ton of “Make It Custom”, Fritzees Fabrications” and “Paint Society” on UTube leading up to this day. It’s been extremely slow going due to temperatures, life and my inexperience.

Today I’m snowed in for a four day weekend vacation in Boston. Waiting to start driving back to NJ in a few hours. This is as good a time as any for a photo dump. I’m about a third of the way through the sheetmetal process. These pictures start from October to last week. So much for getting this done for a spring paint job. I hope it doesn’t turn into a fall paint job.

I know, I know. I should’ve just cab swapped it. But I did, thirty years ago… this was the rust free cab. I just didn’t remember all the half assed dent repair a buddy and I did back then.





















Hopefully good enough for bondo ha!