saggy back ends

I have seen several references to CMC's with saggy rear ends and door post problems.
Can someone expound on the problem and point to the solution.

Thanks
Robert

Robert,
I have an old IM that used to rattle like crazy when going over the smallest of bumps. This winter I had some things done to my car one of which was having the body re-riveted to the frame, now the cars is solid as a rock.
It seems over time (20+ years for my car) and normal wear and tear the rivets stretch and therefore the body loosens. My mechanic did the work, if you'd like I can ask him for the details.

Search the site. Alan Merklin listed a mod/repair for this issue.

is it just me, or can someone find this doing a search?

martin

CMC's predescessor FiberFab (FF) and even the newer JPS/VS models do it too!

Here's the links from a search:

FF Doors
https://www.speedsterowners.com/forum/readmsg.asp?t=9339

CMC Door gap
https://www.speedsterowners.com/forum/readmsg.asp?t=7051

Also there is an active topic at www.speedstershop.com under speedster tech( CMC body fix).

I had the same issue. The body had been sitting for years, and the fibergalss warped down. I tried everything, and could not get dorr gaps straight.

Instead of Riviting, I fabricated some L brackets 18 inches long. Then I took a jack and a 2X4 wrapped in a towel, and slowly jacked up the rear of the fiberglass. I would raise it 1/4 of an inch at a time, and check the door gap. When I had it, I mounted the l brackets to the inside of the side walls in the engine compartment. and to the subframe.

Remember to do it slow. Nothing sounds worse that a fiberglass body cracking.

As for doors, do yourself a favor, and go rent a door dolly from a autoparts store. It keeps it straight and in level for mounting.

There's a door dolly? Man, I have been giving myself headaches over the past couple of days!

Just for the record, this problem only existed on the early CMC/FF cars.

It does NOT exist on JPS, Vintage, Intermeccanica, SAW, Beck, etc. Unfortunately, I have seen the makers of some cars lead people to believe the competition has this problem, it's simply not true.

-=theron

i had a quick look at my car, and i think i understand what you guys are talking about, i have a CMC, and looking under the car, behind the rear wheel, there is a vertical peice that is rivited onto the rear frame made from 2" square tube. The vertical peice is glassed to the rear, which is basically the side engine firewalls, correct????

I quickly lifted the rear quarter just a little by hand and i could see a slight decrease in the door gap and the top went a little loose. So i think i know what to do, there's no other points to do with this fix????

martin

i have'nt seen a vintage sag but i have seen them flex quite alot under rough road conditions , i made supports for the rear and front that really tightened the whole car up , there are pictures in my file that show the supports , thanks ron

Good job! Thanks for sharing, Ron. Just one comment, check the lower front tin on your engine; it seems to be missing and it helps with cooling and also protects the pushrod tubes from road debris. I can see it on one of your pictures; one of the pushrod tubes is clearly visible.

ricardo , you have got a good eye , theres a new motor waiting to be installed and thats one of the things that needs to be handled on the swap , thanks ron .

Martin, You want to address the horizontal run. Look at the pics above see where the inner wheel well sits against the horizontal
structure. Have your trusty assistant wiggle/lift the rear while you look at this area. You will probably see that the fiberglass panel is
moving without the metal frame behind it.

Hi Ron
Looks very good, did you go MIG or arc or gas on that?

kurt , just went mig , the welds are not the best i can do , it was one of those hurry up we have some nice weather welds , i'm in the process of welding it better and possibly adding support else where in the car , i also tied that rear strut bar in with the shock mount that made the most diffrence , no more walking door gaps over rough roads , thanks ron

Hey Ron, Nice work. That front support from frame head to body, did that replace something that was there?

bruce , on mine there was'nt anything there when i bought it , i noticed some bad cowl shake over bumps and started to really look things over , i'll have to take more photos theres more brace work in the front to help support the battery and i also made sure that the body is attached to all of the factory vw mounts , thanks ron .

I find that funny that vintage doesn't support this area (did they forget to install a piece on yours only?). That mount supports everything fwd of the pan firewall. My CMC has it.

bruce , i think vintage does install the front support , this car was built buy an outside source , you might also want to check under your rear seat area there are 4 bolts that go into the factory vw pan / crossmember mine were also missing from there , with all the talk about pan cars flexing and my own observations , i just had to start looking for problems and possible fixes , thanks ron .

I appreciate the dialogue re; sag / can anyone confirm this is limited to the CMC's as noted - one entry indicates that Vintage doesn't have this problem - ???? Jus curious / I have a VS other than some slight movement at the hinge (has since been adjusted at Kirk's shop - haven't experienced this - please advise

FF/CMC are now '80-90 "vintage" shells so they have 25-15 years to sag.