Rust Repair Trunk Area Above Shock Supports 1973 Sport Dart

[dart14]

Got the front floor pans welded in and started the rust encapsulation process. Moving towards the back of the car -1973 340 Sport Dart - the rear floor pan area above the rear shock support after the axle hump is rusted through (about a 14 inch run). Although I have not removed all of the rusted metal on the rear floor pan, the shock support looks intact. Looking for advice / ideas for repairing this. If the shock support is only surface rusted, I was going to make a patch panel and weld it into the rear floor pan and mesh with the shock support. It seems like some additional bracing for the shock support area would be a good idea and looking to see what others have done in this situation. The trunk floor is in pretty good shape and is only rusted in the tire well. I plan on changing the entire trunk pan though as I don't see much positive feedback on just changing the tire well and installing a new trunk pan will save a lot of labor for cleaning the top and bottom of the old trunk pan for paint prep.

 

[Jim Kueneman]

There is a reinforcement plate under that. Doubt that is rusted out. Deep in the throws of that myself...

1968 Barracuda Formula S 340 Spring Special

Jim

 

[azaustin]

There are people far more qualified to answer this on the forum, but what I ran into with rust like this is the hidden rust. My shock mount was rusted through on the trunk side, but didn’t look too bad otherwise. When I removed it however, it was much worse inside than I thought. It’s a tough piece to replace, but I did. Not the same year car, but similar. Photo of how I replaced mine attached. Note that I later also replaced the package tray due to hidden rust. In my experience rust is usually much worse than it appears once you get inside a part.

 

[dart14]

After tearing out more rusted metal, I think the support plate is salvageable. AZAUSTIN - it looks like you got a part from a donor vehicle. Nice installation job. I am planning on fabricating a replacement plate to replace just the rusted out piece of the floor pan starting from just under the shock mount bolts and running about 1 inch short of the trunk pan. If the shcok support bracket needs to be replaced, is there any other option other than a donor vehicle ? I think I remember a previous thread where circle track guys replaced the shock support with 2 inch square tubing.

 

[dart14]

just saw this from Retro-motive......

67-76 Mopar A-Body Upper Rear Crossmember (Shock Mount) #860-1067

67-76 Mopar A-Body Upper Rear Crossmember (Shock Mount) #860-1067​

$219.99

 

[Jim Kueneman]

You can have this one for $50 plus shipping or pickup at Carlisle or Moparty. Will be out next week.

 

[George Jets]

Scary how deep people go into these cars.

The 74 Dart was a Rust Free Florida car, but the spare tire well had a minor issue that I was able to return to factory pristine condition.

The next owner put a supreme paint job on it being the body was so nice.

Kind of a Maroon/Red Sparkling Metallic.

Show Finish

Makes a person appreciate a clean rust free car, if you can ever find one.


☆☆☆☆☆

 

[azaustin]

After tearing out more rusted metal, I think the support plate is salvageable. AZAUSTIN - it looks like you got a part from a donor vehicle. Nice installation job. I am planning on fabricating a replacement plate to replace just the rusted out piece of the floor pan starting from just under the shock mount bolts and running about 1 inch short of the trunk pan. If the shcok support bracket needs to be replaced, is there any other option other than a donor vehicle ? I think I remember a previous thread where circle track guys replaced the shock support with 2 inch square tubing.

Thanks. Looks like you have some good options. I attached a better picture of the mount going in. If you want a shot of the underside I can get it for you tomorrow. It’s up on the lift. Not the same year model but very similar.

 

[dart14]

Yes. please take an underside view picture if you can. Again, are you using a piece from a donor vehicle ? My original question was looking for advice on using a patch panel as to make it look factory original looks like it will be somewhat difficult, at least for me. Thanks for your input.

 

[azaustin]

Patch panels can work too, if done properly. Some people may not care about originality, it just depends on what you want. I wanted my car to look as original as possible, and patch panels weren’t available for a lot or what I needed (everything) so a donor car was the way to go for me. Some pictures attached. Hope they help. The mount was in two pieces, upper and lower lower, and, as I recall, I had to do some sliding around and fitting to get it in for welding. As you can see, it’s a work in process. Lots of people on this site who are better at this than me.

 

[dr dodge]

Patch panels can work too, if done properly. Some people may not care about originality, it just depends on what you want. I wanted my car to look as original as possible, and patch panels weren’t available for a lot or what I needed (everything) so a donor car was the way to go for me. Some pictures attached. Hope they help. The mount was in two pieces, upper and lower lower, and, as I recall, I had to do some sliding around and fitting to get it in for welding. As you can see, it’s a work in process. Lots of people on this site who are better at this than me.

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that looks very good

 

[dart14]

that looks very good

great photos !

 

[azaustin]

Thanks. You caught me at just the right time. I had just put the coupe up on the lift for the summer because we were leaving today for our summer cabin. I’m hoping to get back on it in the Fall after I finish up the interior in the convertible.