CMC Door Gap

I can't seem to find the article here on how to fix the CMC door gap problem.
Paul

Gap at tops of doors in rear? Do search on "CMC Butt sag"

https://www.speedsterowners.com/forum/readmsg.asp?t=11981

thanks for the info. Now, all I need to do is find someone in Arizona that can fix it. I don't think Vintage works on other makes of speedsters, or I would drive over to California.
Paul

Paul,
You can fix this yourself in under two hours and about $20 bucks.

You'll need a floor jack,a set of jack stands, drill, 4 ft pc. of 2x4, 10 - 5/16 bolts, fender washers, regular washers, nyloc nuts and some construction adhesive.

Complete the repair one side at a time.

Put the car on four jack stands ( don't put just two them on the rear as it may cause it to to stress a bit while doing the repair.) Remove the rear wheels. Place the 2 x 4 centered on the floor jack pad. Raise the 2 x 4 on the jack up to meet rear body section below the bumper ( not on the bumper) until you just make contact, this will relieve the tension on the factory installed rivets that are located horizontally in the wheel wheels.
First drill out the rivets, then slowly jack up on the rear body section just a bit until you have an even vertical door gap. Now drill new 5/16 holes into the wheel well panel and 2 x 2 steel, pull the fiberglass wheel well panel away from the 2 x 2 steel tube with two large screwdrivers, apply some construction adhesive between the panel and the 2 x 2 and remove the screwdrivers. Slide a fender washer on a 5/15 bolt, pass it through the new hole you hole add another washer on the 2 x 2 steel side and a nyloc nut doing the same four more times spaced evenly or as close as you can on that same wheel well side. Repeat the process on the other side . ~Alan
PS. What did you do with the 34mm Webers?

Okay....Thanks much, I'll give it a try. My door gap is about 3/8 " or 9mm at the top. Both sides about the same.
Paul

Alan, I gave the old Webers to a friend in St. George, Utah that's re-building a Bug.

In your CMC sag problem fix; is the construction mastic used in place of welding a new support brace? Or, would it be best to have a new brace welded? I think Vintage puts a big plat of metal as a support. The best thing about a Vintage is, they have built over 2000 cars. As someone wrote; There's nothing wrong with a CMC, it's the person who built it. I'm sure the Vintage people could take a CMC kit and make a very nice car.
Paul

Paul,
The construction adhesive is used in place of welding a new support brace, I've done tbis on several CMC resto's, it works.. ..If you can get some "Corvette glue" that stuff it great. ~Alan

Alan...this was all I could find on Corvette Glue.
http://www.amazon.com/Corvette-Chemicals-Bonding-Adhesive-Corvettes/dp/B000ET60U6

Paul

"Corvette glue" is a loose term for a number of fiberglass adhesives and available at any auto body supply house. Good sh*t just don't use it in an enclosed garage area or let it dry on your hands as you'll wear it for a few days. (stains skin just like GM windshield adhesive)
My bad as I took it for granted saying... Corvette glue as a general term. ~Alan

It's not the heavy steel that's saggging - its the fiberglass skin slidding on the few pop rivets. The fiberglass is heavy hanginh out there with only the rivets supporting it. Adding steel will increase regidity of frame some - but doubt its needed unless a big engine is hanging off back with added rear support bar. If they had glassed a 1x1" strip of wood into the fiber panel above the steel frame instead of simply riveting then don't think the problem would occur. I suspect many did not fiberglass in the rear fiberglass pieces that came with kit (mine are bolted but not yet fiberglassed). (There are ones in front that do same support roll).

I'd love to know how many FF/CMC Speedsters were produced - guess is 8-10 thousand.

"its the fiberglass skin slidding on the few pop rivets."

Okay! Now I understand. I thought it was the metal sagging. So, I don't need to spend $89.00 for a can of this fiber glass, "Corvette Glue?"
Paul

I used Locktite Power Grab construction adhesive that's like liquid nails and was in same section of HW store. It comes in aerosol can and a caulking gun tube. It helps to secure the fiberglass to the steel - good to rough FG up as it may have wax on surface. I used stainless steel fasteners.

Posted by Alan
"Put the car on four jack stands ( don't put just two them on the rear as it may cause it to to stress a bit while doing the repair.) Remove the rear wheels. Place the 2 x 4 centered on the floor jack pad. Raise the 2 x 4 on the jack up to meet rear body section below the bumper ( not on the bumper) until you just make contact, this will relieve the tension on the factory installed rivets that are located horizontally in the wheel wheels."


." Raise the 2 x 4 on the jack up to meet rear body section below the bumper"

Looks as if I will have to remove my muffler or put several pieces of wood together and work around the tail pipes???

"this will relieve the tension on the factory installed rivets that are located horizontally in the wheel wheels."
My car has rivets in fender well and all the way to the back part of the car. So, I would surmise that I need to remove ALL attaching rivets on the side of the car.
Paul

You can build up a few blocks instead of pulling the exhaust....
Yes all the rivets (5 or so)need to be removed/drilled out from the horizontal line at the bottom of the fender well panel. As you get closer to the back, an angle drill will make life easier. ~Alan

<<<<<. Place the 2 x 4 centered on the floor jack pad. Raise the 2 x 4 on the jack up to meet rear body section below the bumper ( not on the bumper) until you just make contact, this will relieve the tension on the factory installed rivets that are located horizontally in the wheel wheels. >>>>>>

Even though you're doing one side at a time; I would presume you mean to center the floor jack in the middle of the body, not just the side I'm going to do first. I am going to get all the material together soon, four floor jack stands, etc. Are 5/16 th. bolts big enough? Can the old rivets be cut with a hacksaw blade or must they be drilled out?
Paul

Yes I center the jack on the rear body section...I think you would butcher things with a hack saw so best to drill out the rivets.
5/16" bolts are fine. Have fun ! ~Alan

Does drilling all the way through the frame area make the frame less rigid when putting in the bolts? It sounds like you drill all the way through the frame area? Thanks, this is a huge help as I removed the engine and this will make access easier.

Bolts in the drilled hole ( all the way through) act as gussets, the 2 x 2 doesn't loose any strength.

I'm getting all the tools and material together to do this "Butt Sag" fix. Do these 5/16 bolts, nuts and washers have to be stainless steel? If so, I'll net to sell a kidney. Local store wanted almost $5.00 for a stainless 5/16 x 3" bolt.
Paul

Use regular mild steel and rattle can them after you have them installed.

Paul,
You can do it Alan's way or if you still want stainless I have purchased contractor packs of hardware at my local Lowes in the hardware dept. Much better deal than one at a time.
Dale

Paul, try to find another store. I buy them one at a time for much less.

I think that Paul is procrastinating in hopes that someone will step up and do the job for him.
You give the hole a good drilling, followed by a proper screwing, make'n sure your nuts are tight... I'm just say'n ~

Yeah, but who can do it so many times?!

It would take me weeks, doing 2 or three a week.

He is probably younger than me.

Ya know they have pills for that, doncha Mike?

Yes, but I'm a little self conscious about telling the young girl behind the counter what I am there to pick up.

Just look her in the eye and say; "I'm old.....and I'm GREAT!"

Thanks to all for the help. I did the job this morning. Had to buy a new drill motor and a 90 degree attachment. Two of the new hole, a standard drill motor with drill bit would not fit. I also bough a $9.00 5/16th. metal drill bit. That turned out to be a good investment . By the time I drilled the 10th hole, the bit was about worn out. I had to readjust door molding on driver's side. I ended up using Locktite Power Grip. I am going to leave the car on jack stands and keep the floor jack supporting the rear body overnight. It will give the Locktite time to dry well.
Paul

Glad it worked out well for you ... ~Alan

Wow! Drove car today, after Butt Sag fix. Replacing the rivets with the 5/16 inch bolts, washers and locking nuts really stiffened up the car. 90% of my rattles have vanished! The car even feels better. Sag or no sag, replacing the rivets with bolts is no doubt a good idea.
Paul

Congrats, Paul. Job well-done.

Don't you love it when a plan works?! NICE!

I am still going to go back and run a brace from the rear bolt and attach it to the vertical frame riser. That will help stop the frame from ever sagging.
Paul

I have to remove my engine to finish the engine bay and since my never completed speedster has never been on the road, this would be a good time to be pro-active. I also like the idea of running a brace from the rear to the verticle post as well, any pics? Also I found a decent price on a right angle drill attachment. This list is a huge help for newbie speedster guyz.
http://www.amazon.com/Milwaukee-49-22-8510-Right-Angle-Attachment/dp/B000BYEJ02

This right angle is great and priced right ...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330391113381&ssPageName=STRK:MEWNX:IT

Wow! That's a great drill attachment. The one I got is the size of rear differental. IMO, Don't get too carried away and drill the holes too large. Mine are 5/16 th. When I do the metal strip from the rear bolt to the vertical frame riser, I am going to use 3/8 th. or something less than 1/2 inch. just on the rear bolt and riser. I'll leave the 5/16th. as shown in my photo.
Paul

It is the metal frame sagging and needs to be braced back up to the correct position.
How can the fiberglass sag when it is riveted to the frame?
What about the slots for the bumper brackets when only the body is raised?

I added a brace at the rear, 6x50mm bar bolted to the "riser" at the B post and down at 45deg to the engine perimeter frame...I also bolted the same material to the B post upright, through the bodywork to give me the top fixing for the 3 point seatbelt

Seatbelt test here requires "adequate bracing" for the anchor...

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The rivets are small, at best 1/8" (3mm). They wear and the body shifts over time. On my drive's side, two of the five rivets has actually popped out.
Paul