YYZ06

I've done a couple searches and have seen threads with folks going to remove the studs but haven't seen one where someone has actually done it.

I installed some Corbeau A4 seats and got the supports on for the BK harness bar on with good thread engagement. However, I'm concerned about having enough thread engagement with the Vetteworks sub belt bar. I was thinking I'd be better off changing out the studs for Grade 8 bolts that are a bit longer than the stock studs.

I've heard of grinding off the bottom of the stud and pushing them up through the floor but was wondering why can't the be pounded back through the bottom? They seem to be bonded in place with some type of plastic or epoxy.

What is the best way to remove the studs on a C5 to use bolts instead?

Falcon

Grind the head off the bolt. You'll have to get under the car to do that. Once the head is off, you can push it out from the top.

sperkins

I didn't have access to a grinder so I hammered them out from inside the car. I put a socket on a floor jack and put it around the bolt head from under the car. Make sense?

BTW - those bolt heads are only tack welded in three spots around the perimeter. It doesn't take much to pop them out. You'll be surprised at how thin the flat bar is that they're welded to. I would pick up some 1/8" flat bar, drill holes to match the floor and run your new bolts through them as an added safety measure.

Here is how I did it on my old car.

YYZ06

Excellent idea. Thanks!

davidfarmer

I thought you could just bang them out with a hammer, from the inside. I don't remember needing to support them as sperkins said, but it sounds like a good idea.

John Shiels

B
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!

jlutherva

No, no, no!

just thread the nut onto the bolt from the top and wiggle it back and forth with vise grips. They come right out.


Jim

Jason

Sometimes that works, sometimes the weld is better than others and the cross bracket tears. Anything that can be a PITA, eventually will.

Falcon

Yep, I tried all those methods mentioned in this thread and managed to completely screw up the bolt from the top, but it still wouldn't let go. I used a BFH and even a GBFH's, but it wouldn't punch through.

That's when I broke out the grinder from the bottom, and it was easy.

fatbillybob

If you want more security I would have added the 1/8" bar all the way to the tunnel and the outter sill box and tack welded it. If you end inside those points on the thin GM bar how is that stronger? All you do is move the weakest failure point to the end of the new 1/8" bar. I'm not an engineer so maybe I'm wrong.

Jason

Scott needs ballast so all of his brackets are 1/2" steel.

sperkins

Have you ever seen how thin that OEM cross bar is? By putting the bar there you're spreadig the load from two 1/2" holes to the entire cross section.

YYZ06

I ended up using sperkins method. I had previously installed some Corbeau seats and had the rear bolts and B-K harness bar supports installed. I didn't want to take that apart to remove the seat. I used a cold chisel and a 3 1/2 pound hammer and supported the bottom using a jack and 24 mm deep socket. It went pretty smooth after I got the hang of it. The method was, pound the stud from the top until there is some separation of the stud head and the brace then use the cold chisel to break the welds holding the stud.

After removing the first one, I decided to try the grind off the bottom method on the second one. I felt that I'd be older and grayer than I already am before grinding it all the way down and went back to the hammer and chisel. If the seat was out, it would have been really smooth because I could have pounded straight down. I had to work around the seat bracket but it was still much faster than grinding the bottoms off.

I also reinforced the area with 1/8" Steel. The spot welds tear the metal a bit so I like the idea of spreading the load a little more.

Here are the tools:


The bolt with the three spot welds (as previously mentioned):


The brace after the bolt is removed:


The finished product:


Thanks for the help!

sperkins

moespeeds

Just curious, you guys that are pulling the studs, what size bolts you putting back in, Grade 8, 1/2"?

YYZ06

I used Grade 8 - 3/8 x 2" coarse thread flange bolts. I'd say one could get by with 1.5". I have the Corbeau seat brackets and Veteworks sub-belt bracket.

Pix

Bossdog

Thanks for all the great info. I'm getting ready to add the Corbeau A4's to my C5Z along with the sub belt mount. I'll use all the great info here.

waddisme

Wow! Talk about a blast from the past. Where you been man? I was thinking the other day about all the guys who used to rule this forum. You, An U Egl, Varkwso, brkntxn, cobra4b, jason?, 9?Jersey are some of the names. Never see them on here any more. I guess they've gone to Miata forum?

Welcome back.

Scooter70

Check the post dates. Someone brought a thread back from the depths of the archives.

waddisme