Stress cracks

Are you sure these are stress cracks and not "lead cracks"? Panteras will crack at the seams. These are not structural but are in the filler in the factory joints. They can be ground out and re-filled.
Richard T.

The rigidity kits sold by several venders, ie. Precision Proformance, will stop stress cracks. I had started seeing them on my blue car, especially after running the car on the track. Installed the rigidity kit and although I ran the car at quite a few track events, never saw any more cracks, or had any of the existing cracks get worse.

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The rigidity kits

How does this prevent cracks on the roof posts ??

All these ridgity braces are for suspension areas ..I think if you really want to stop cracks on the roof ..add a roll cage and strenghten the frame where they end on the door jambs ..

Ron

I'm with Rapid. Since I installed my kit the cracks never worsened, nor did i get any new ones.

Have someone drive your car and you drive close behind it. Do this before you install the kit. You will be amazed how much it flexes. You will see the rear deck look like the sides are bouncing - eg; the space between the body and the deck at the two sides opens and closes. Almost 3/4" in my case. I thought it was the deck moving, but it was the chassis flexing. Crazy thing to watch!

It is usualy the lead that was used in the olden days because an artisan with a torch could make seems smooth as silk. Back in those days lead was considered better than bondo. But what happens is lead work hardens just like any other metal from being bent back and forth. So if the chassis is made stiffer it may stop the cracking momentarily, but if the chassis gets weaker due to rust or other issues such as tack welds letting loose, they will start all over again.
The bestest way in the whole world to fix it is of course prohibatively expensive. That would be to strip the car down to bare metal, remove the lead, (with lead exposure being what it is, grinding isn't recommended, but flame wicking might be) and then stich weld all seams, where just the factory tack weld existed before. This greatly increases chassis rigidity in and of itself. Then if you add braceing you have race car rigidity. Of course any rust anywhere will have been repaired during this process and use of a good quality steel will go a long way in helping resist future attacks on your cars structural integrity. Todays modern body fillers are not as prone to cracking and can also aid in protection of the understructure. But unless you are one of the rare artisans who can perform this work yourself, like Gary in Indiana, it will cost you more than the value of the car to have it done.
So yeah a brace kit is about the only way to slow it down. That are stop tracking the car and drive it under 40 mph for the rest of your life.

stress cracks from driving = thumbs up
scrape marks from loading it on a trailer = thumbs down

Wear your stress cracks proudly!

On my Group 4 I know extra metal was welded around the lights and also in the upper areas above the quarter windows. I have a piece of metal kind of trangle shape and curved that I understand can be welded into the area above the quarter glass. I will fish it out of my parts stuff and do a photo if anyone is interested in seeing. I run my Group 4 pretty hard on occasion, and no cracks yet, and no brace or other stiffing devices used. So, maybe one of the keys is to build those areas up when restoring the car. It also has a metal bottom belly welded under the car, so maybe that could add some stability, I am not sure.

I would also like to see some pics of the reinforcements welded in the weak areas
I did a search in the BB on this topic some time ago and found several discussions on this matter but no pics. I talked to Dennis Quella about this topic also and he said the windshield post, the rear roof and the tail light area are the areas that usually have problems. I am in the process of stripping my car to bare metal and want to reinforce these areas. My car was made out of bondo so there are cracks everywhere. I plan on welding all the seams but would like to know if there are some plates that need to be made. I will not be running a roll cage in my car. I can barely fit in it as is.

So I guess the winter project is settled.
Remove paint and lead, reinforce and weld the affected areas, and get it painted ++
To make it even more unlikely to re-apear, I would like to have your choise/recomendation for the handling/stiffening kit that would be the first choice.
Thks.

Frode
#1155
#11

According to G. Malmberg (http://www.hemipanter.se/#Chassis%20and%20components)"The steel body of the Pantera does not tolerate rust as this completeley obliterates torsionall stability. In a 30 year old car rust is a problem. No two ways about it! I have torsion tested a number of Pantera chassis. Rusted as well as rebuilt. A rebuilt (or new) chassis is stiff enough for hard street use. Rusted are NEVER!. I tested a nice looking chassis that could only hold 700 foot pound/degree!!! On this car almost all of the profiled middle rocker pantel section was rusted out.

Torsional stability.

700 fp rust figures, has given Pantera a bad stiffness reputaion. Especially since the car not seldom looks quite sound from the outside. Thus making it easy to put it down to bad engineering . People then start to bolt on all kinds of stiffening devices in place of fixing the rust. But even a sound Pantera could use a few more foot pounds of stiffness. When twisting the chassis it is easily seen where flex occurs. Stiffening of those areas by triangulation, is not always easily accomplished. One would prefer be able to get in and out the car, have a motor in the engine bay, etc. This very often result in tubes positioned where there is space left. Bent tubes, and tube joints where the tube intersection does not line up. Tube reinforcements also create new stress concentrations and weak points elsewhere."

I think G. Malmberg hit the "bulls eye". Adding a handeling/stiffening kit may cure the symptoms, but not the cause.

I am in the prosess of "some bodywork" on # 6287. Rear att. points for the suspention, channels from rearplate to Firewall, B-posts to rocker panel and reinforcements on the floor/footwells.

I am half way in the welding prosess. My point is that a nice looking car -may have some issues inside.. As the Germans say: "Ausser blank, inner krank"

Very well put EV!

My car was a basket case. I have changed about all of the under part of the front. The channels under the floor in the front both sides.The rocker panels outer, midle and inner on both sides. Both B pillars. The roof. In the rear the mid section at the lower back, and parts of the inner wheel wells both sides.
I did not remove all paint and old lead, and beleive that the cracks I have now is in the area where this is added to the body.
After installing the new 408 inch. EFI stroker engine, I believe the power and torque is a bit over the edge, at least the cracks became visible after this.
At least my ZF differential did not aprove of the added effect.
Some of the guys on this forum say they have stopped the cracks from developing further by adding stiffening or handling kits.
In my mind it´s worth a try. But what kit to buy ?
Frode
#1155

Let me pose a question to everyone based upon an observation that I made long ago.

My impression of what I saw was that EVERY Pantera that had been stripped of it's original paint and repainted showed "cracks in the paint", particularly in the roof in the curve near the deck hinges.

I never saw that in an original car. I have them in my car which was striped and repainted. I have already determined that it is the paint that is cracked and not the sheetmetal.

Is everyone sure that the sheet metal is cracked and not just the paint?

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Is everyone sure that the sheet metal is cracked and not just the paint?

It's not the sheet metal per se. It can be from popped rivets, stess cracks in the leading, work hardened cracks in the leading, and just the cracks in the paint.