big problem with floor rust, how to fix the cause

[moparmat2000]

you know a big problem with the floor rust thru on these A and B body mopars besides a leaking windshield gasket which is actually pretty rare if its installed properly, is actually caused by leaking wiper arm shafts. after all you can fix the floorpan, which is just the result of the leak and years of soggy carpet padding eating away at the metal, or you can fix the floor, then take the necessary steps to prevent a future leak

the seal for the rotating wiper arm shaft to the cast pot metal housing dries out and lets water inside the car since the back half of this part is inside the cowl behind the dashboard.

what i did with mine on both of my 2 old dodge charger restorations was to remove these parts from behind the dash when i took each car apart, drilled a hole in each of the housings in an angle that would be accessable when they were remounted, installed a grease fitting in each hole, and pumped a small amount of ball joint grease in each one. this not only lubes up the shafts for the wipers, but makes a seal to keep the water out of the interior.

if there isnt too much room to install grease fittings, you can still drill a pin hole with a #40 or 1/16" drill bit , and use a pin oiler that attaches to a grease gun to fill these housings with grease.

works like a champ

i will be doing this on my 67 cuda as well when the resto starts. not sure if theres enough room on the A body housings to install grease fittings, or if i will have to just make a pin hole to grease them up. i guess i will find out when the car gets pulled apart.

hope this helps
matt

 

[MtNemoMopar]

Yes. That and moving to Arizona both work.

 

[moparmat2000]

that much may be true, as little rain as arizona gets, and the fact that the roads are not salted like in the notheren climates in the winter. even living in AZ you will still have this problem even if its to a lesser degree. the floors still get eaten away as the water from even those scarce rainstoms in AZ, or even washing your ride will allow the water to get under that carpet. being that its trapped between the carpet padding, the metal floorpan really doesnt get a good chance to dry out. it will eventually rust thru.

most floorpan rust thru i have seen and repaired in all my tinkering with cars seems to be caused by water / moisture trapped between the carpet padding, and the floorpan.

my 67 cuda was a west texas car all its life, 42 years worth. we get some rain in the spring and fall but its mostly a dry climate. i still am dealing with 2 fairly large holes in the front floorpans from a soggy carpet caused by leaking wiper seals. it must be said that the framerails, rockers, lowers in the doors, fenders and rear quarters in my cuda are all solid only needing minor body work and no rust repair. even the front fenderwell on the battery box side is solid.

trunk floor has the usual rusty spare tire well caused by a leaking back window gasket. they make patch panels for this type of damage so its no big deal, tho i may run a fuel cell anyways in which case i will remove the tire well and sheetmetal the floor flat.

matt