80L82

Hey everybody......

I've got a 1972 I'm looking at and the guy says the frame is good with the exception of the rear crossmember. Won't pass inspection. I'm waiting on pics, but is this a big deal? Sorry for being a frame newbie. I just don't want to get myself in a hole.

Thanks!

Mooser

Well if it's the crossmember that the rear differential is bolted to, it's a pretty big deal, spring is connected to the diff, lower strut rods are connected to the diff. so if the crossmember is sketchy and the diff is connected to it and everything else is connected to the diff....

Here's the crossmember with just the diff attached


That being said, the cross member did have a tendency to fill full of crap and disintegrate so just because it's bad doesn't mean everything back there is bad.
Bit of a job to replace since so much is attached to it but certainly doable

Replacement crossmembers are around and not too crazy in price

Mooser

Ben Lurkin

Better look at that thing really close. If the crossmember is gone due to corrosion, chances are therse other problems. Search "birdcage" for more info.

80L82

From this pic it looks like not a big deal outside of the labor. I'm more concerned it could be a sign there are other problems with the frame. He said his mechanic looked at it and said the sides of the frame were fine. I will check out the birdcage.....

Mike Ward

The diff crossmember is not the weak spot on these cars. Beware.

80L82

What is the weak spot I should be looking for? Any input is appreciated!!

Jud Chapin

If you are not sure, have someone who knows what they are doing look at the car on a lift to avoid making a costly mistake.

Mooser

Vette's have the remarkable ability to be totally rotted out in one spot and then really good only inches away.

Some "normal" areas are the aforementioned birdcage where water ran and sat, rad support (similiar thing with water sitting) this crossmember (not so much water but whatever it was made from seems to flaking) the #4 body mount (rear wheel flung stuff at it forever)

Some are an easy fix, some are a giant hole at which you can through money at for a long time and never actually fill.

Careful, pretty cars can affect your judgement
Mooser

80L82

If nothing is glaringly obvious, I'll have someone look at it. It is a 'pretty' car as you said, and the price is good. Two things that can lead to bad judgements!

mysixtynine

You need to get under there and look for yourself.

Get us some pics and post them.

If its the differential crossmember thats truly bad then I can almost guaranty your side rails and the #3 crossmember will be toasty as well.

I'd like to know what "inspection" he means.... does he mean DMV inspection?

80L82

Yeah, I believe he meant DMV inspection...

I'll post pics as soon as he gets them to me....

80L82

Just spoke with John from John's Corvette in Laconia. He said that if that crossmember is rusted out so is everything else, and not to go near it. He did all the work on my '80. Do you guys agree?

Red 69

I've worked on rusty frames, but the differential cross member's were in decent condition. If it is badly rusted, I don't see how the rest of the frame went unaffected. Ask to pull the kick panels and look at the #2 body mount. Kick panels are to the right and left of your feet. If there is rust in the windshield frame, it will show up down there. Water leaks past the seals, gets into the windshield frame and runs down the A-pillar. The result of this shows in the kick panel. Cars stored in a garage and only driven in good weather were spared from this happening. As already said, if there are signs of excessive rust, best to pass. The trick is to know what is excessive rust and what is manageable. They will all have some rust, as these parts were not coated with any protection from the factory. Good Luck!

80L82

Thanks! I'll keep everyone posted. If this falls through I'll probably go back to looking for another 1980...

Peterbuilt

http://corvettec3.ca/rustpics/index.html

80L82

Thanks for the link! I told him that I would need a pro to look at the frame. I'm going to go check it out myself and see if it's even worth taking it to someone to see it further.

Kerrmudgeon

I've found it's not the crossmembers that go first, it's the brackets on the frame that they bolt to. They're pretty thin material, and have quite a bit of downward stress on them on the drivers side. A actually broke one that was rusty after an exhuberant stomp on the throttle! Whole rear end assembly came down and hooked itself in the wrong position which made the car 3 inches higher on that side!

80L82

Well guys thanks for the help, but I passed on this one. Even after the guy lowered his price 25%. I don't think he was a scammer just didn't know what he was buying.

Sooo.....I just purchased a 1980 L82 !!!

http://forums.corvetteforum.com/c3-g...9-im-back.html