I carry a *lot* of stuff up there - including a large rooftop
Post-having the front end overhauled - for which I had to remove
all that junk so the vehicle would go high enough on the lift
without hitting the ceiling - I got to take close look at the
attachment points while replacing the roof racks
Right side doesn't seem to show any signs of rust, but two of the
left side's attachment points show what I'd call significant
Sure would spoil a day to go head-to-head with some 18-wheeler
and have the gust lift the whole enchilada off.
Looks bad to me, but what do I know?
My kneejerk reaction was to unscrew the Torx bolts holding the
roof rack anchor points in place, remove the whole thing, scrape
away the bubbled paint, slather everything with rust converter,
let it dry, and then re-assemble using Never-Seize on the bolts
and/or maybe even replacing them with stainless steel bolts if I
can find same.
But when I tried loosening one of the Torx screws, it was
scary-tight - as in maybe the bold would shear.
I wouldn't be averse to taking the whole rack system off and
drilling/bolting some aftermarket system through the roof - but I
don't know what I'm doing.
Anybody been here? What's my fallback position if a bolt
How about the prognosis for progression of the rust?
SHB "...maybe the bolt would shear."
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I don't know how they do it on modern vehicles, but in the days of
station wagon roof carriers.... They used a cheap wellnut setup. It
was a rubber grommet with a metal threaded insert. The screw would
cause the rubber to swell and this tightened against the sheet metal of
the roof panel. I'm sure that you'll find a similar gizmo under yours.
I don't think the screws go into a structure under the roof panel. This
will be one of those times that if you start this project, you'll have
to finish it, no matter what you run into. In other words, the roof
panel may have enough rust that once you mess with it, maybe the hole
will become enlarged and you might have a major repair coming. If it
ain't loose or leaking, I'd say leave it alone.
What usually happens is the rack is left a bit rough. Then with the
movement of the roof through vibration those rough spots wear through
the paint. Then it starts to rust. Same problem you see with the wheel
arch moldings and many other add ons. They all move some and eventually
wear through the paint.
I'm betting that one side has more weight on it as well.
I removed one corner on my 95. The torx bolts are tight, from rust. Some PB
blaster loosend it up, but was still a PIA.
Needed to work the bolt out.
The nuts appear to be a PEM style nut, they didnt fall in, and looked as if they
were embedded inthe roof.
The nuts the torx screws bolt into are called rivnuts.
Drill the torx bolt head off with a 3/16" drill bit, being careful not to
damage the rack.
Grind the head of the rivnut off, under the nuthead is where the rust
Grind the rust off, within the confined area of the rack mount, use a good
spray can primer. After you tape the area sized like the rack mount. Then
let it dry well, and spray clear over the primer. Primer is very porous.
Let that dry, then buy nut seatable type rivnuts, so you wont have to buy
Remount rack, and it will be good for another 8 years.
I personally do this as a living, so I do the whole roof.
I hope this helps.
Thanks for all the inside scoop.
Sounds to me like this is a several-day project for someone like
me.... and I'd better have all the right parts available
Care to opine on why it's just some attachment points and not
others - particularly why one side of the vehicle and not the
Or could there be rust all around that just hasn't bubbled the
I would opine that;
More than likely, there is a bit of rust at every rivnut.
Now that they are available in the bolt set bit, rather than the really hard
ones, that you'll need the gun for.
I'm sure you can do fine, just make sure of one thing, if you have to grind
beyond the base area of the rack, you can tape a shape of the base a bit
Even up two inches bigger, and use the blue 3m fine line masming tape. So
you won't have such a high edge.
Then use the 3M 411 Plus green tape for all the other masking. A few dollars
saved on cheap masking products, can cause the need for repainting the whole
How about a *lot* of rust?
Here's what I found in the one the looked the most egregious on
The Torx bolts came out fairly easily, and I figured I was on a
roll. "Lets take all these babies off and see what's under
Went up to the next station - no rust at all apparent.
Oops! Promptly buggered the Torx receptacles. Maybe #25 Torx
was close... but not close enough?
Anyhow, that's it for now.... until I have the time/determination
to do something more drastic to get the frozen and/or buggered
bolts loose and deal with the expected repetitions.
I'm guessing with the buggered ones, it would involve peeling
back the headliner and attacking the rivnuts from the bottom.
On the successfully-removed rear station, I scraped away the
bubbles, slathered the area and rivnuts with rust converter, then
re-assembled with liberal amounts of Never-Seize on the bolts.
My guess is that there's more corrosion going on under all of the
stations. The rivenuts look to me like one of those things
that's just a bad idea..... Trannie valve bodies.... Intake
manifold gaskets.... now these things. Thanks again GM!
Got about 160k on the vehicle now.... Just spent well over a
grand having the front end moving parts replaced (drives like new
now...) Was going to go for 250, but now I guess I need to
watch and wait. Maybe that SprinterVan I've been fantasizing
about is closer than I had thought.
In a way, I'm glad I didn't know what was under there on day 1
when I bought the vehicle new - or I would have been fretting
about it not being robust enough. OTOH, I guess the more weight
is up there, the harder it is for a gust to lift everything hard
enough to pull something loose.
Looked at a 2007 'Burb today and they've cut back the bolts from
two per station on the intermediate stations to one. Maybe they
did something more robust underneath... but the cynic in me said
"Gee, they must've saved a whole 47 cents on that one."
Thanks again for the advice and info.
And the rust converter is not an adequate seal?
In case of the expected "yes", I guess it's take everything off,
sand smooth, feathering into the surrounding good paint, prime,
and paint with proper enamel?
I'm a little surprised I didn't see rust propagating from around
the rivnuts. I guess I just got lucky with the rust nearby - or
did somebody say something about vibration and the load working
on the paint's adhesion?
From years of experience with the rust convertors on the market, the only
proper fix is to sand blast with arecirculating sand blaster.
Then any brown spots get the convertor, then sandblast again.
Prime, and paint.
The convertors are for thin rust, not stratified rust.
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