Panel Gaps/ Body alignment

[Ken B]

I feel like I am chasing my tail on body panel alignment. Looking for experience/ wisdom from others . I locked down the core support and hung fenders , doors are on the replacement cab, bed is on the frame. Just start from the core support and start trying to adjust panels?
THe pass door is too tight to the fender and rubs. The door is "forward" in the door opening in the cab, can i use washers/shims to push the door back in the cab?
Hope this description makes sense

 

[legopnuematic]

Start from the back of the cab forward. Get the doors lined up to the cab, then fenders, then tighten core support mounts.

The back of the cab is a datum, or fixed reference, then things can go forward to provide the clearance needed. You can bolt the fenders to the core support, but leave the mounts loose. That is how these were assembled.

 

[Toad455]

I feel like I am chasing my tail on body panel alignment. Looking for experience/ wisdom from others . I locked down the core support and hung fenders , doors are on the replacement cab, bed is on the frame. Just start from the core support and start trying to adjust panels?
THe pass door is too tight to the fender and rubs. The door is "forward" in the door opening in the cab, can i use washers/shims to push the door back in the cab?
Hope this description makes sense

I'm doing the same thing on my 78. Where the hinges bolt to the cab there should be enough adjustment to move the door towards the rear. I hope you have at least one helper, it makes it a lot easier.

 

[TotalyHucked]

Start from the back of the cab forward. Get the doors lined up to the cab, then fenders, then tighten core support mounts.

The back of the cab is a datum, or fixed reference, then things can go forward to provide the clearance needed. You can bolt the fenders to the core support, but leave the mounts loose. That is how these were assembled.

This. Leave everything loose. Get the doors lined up to the back cab panel and top of the door frame first. Then hang the fenders and hood (again, everything loose) and work them in. At that point, you may need to move the doors in or out, but shouldn't have to adjust them any other direction since they match the cab. Make the fenders fit the doors is the goal. The core support is the last thing you lock down. Also keep in mind, there's only so much consistency you'll get on these trucks without doing custom "gapping" work. Don't beat yourself up if you don't get a perfect gap on every panel.

 

[legopnuematic]

Two more things, if you look in the service/overhaul manual, somewhere there should be a page with the gaps and their tolerances.

Second is hanging doors with the fenders off is 1000% easier than doing it with them on. I put the hinges on the cab, put the door into the door opening, latch the rear on the striker. That holds it enough to get a bolt caught, snug them lightly, then adjust to the a pillar and rocker. Tighten up, should be really close. You can (if the door panel is off) adjust the striker with the door latched.

 

[Ken B]

all good info. thanks
Basically every bolt is in place but non are tight.....hahhaa

 

[TotalyHucked]

Also, don't be surprised if you have different amounts of shims in the same location on the fenders or the doors.

 

[Ken B]

that makes sense.
it just seems odd that the pass door seems to sit forward in the cab , big gap in the back(latch side) and no adjustability.....these are all "new to me" they werent from the factory together.

 

[TotalyHucked]

that makes sense.
it just seems odd that the pass door seems to sit forward in the cab , big gap in the back(latch side) and no adjustability.....these are all "new to me" they werent from the factory together.

Got any pictures? That's also not uncommon, there is ALOT of variation from truck to truck. There's this belief in the sheetmetal world that OE is better no matter what. But speaking from experience (I help with R&D at AMD), factory doors can get hung on 5 different cabs and fit 4 different ways. There was HUGEEEEE variation from truck to truck to truck back then. If a door didn't fit a cab super well, they'd just call 350lb Bubba over to tweak it till it fit, whether that meant a hammer and a block of wood, leaning on it till it came down 3/4", whatever it took to get it out the door.

If your door is that far off, you may need to find another or open up the holes on the hinges to get more adjustment.

 

[Ken B]

I will get some pics
I have just been scratching my head on getting the door to sit back farther in the cab. since the hinges have bolt from inside and outside. I am saying it is off I would say double what it should be maybe. Not looking for perfection, just close and something that doesnt grab your eye......

 

[Ken B]

pic of both side. just seems wide to me. can I put a flash washer between the door and the hinge on all bolts to push it back?

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[Ken B]

thanks for passing the help. or I might just stand there and stare at the truck trying to decide where to start......once I get started its fine, its just getting a starting point.
Got the cab mounts tightened and torqued gonna get doors close if possible then get the fenders on. gotta loosen core mounts

 

[legopnuematic]

This is from the 1979 service manual, but good basic information on gaps, dimensions and tolerances.

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[mxer147]

Door gap

How thick (inches) is the gap between the door bottom and rocker panel?

www.gmsquarebody.com

Snoots provides a great description for installing and setting gaps.

 

[TotalyHucked]

Another thing, are the hinges new? Here's some pictures I took of various trucks we have in the shop. The blue one is my '85 with very worn driver's hinge (actually discovered the upper rear of my driver's door is now contacting the back cab panel). The pass door has a much better hinge but still is sagging a touch. Measures ~3/8" at the bottom and get to ~1/4" as you go up.

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The gold truck is a 68k original mile '76. It measures roughly 3/8" all the way up the driver's door

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