Floor Pans and Undercarriage

DSCF0016After I removed my Mustang from Paint Shop Prison II (PSPII) I went to work starting with a Dry-Build to see how the sheet metal would line up and document those issues before I got into the body work and structural issues that remained.

I knew that I had to take a good look at the Mustang floor pan replacement that PSPI had performed. I also knew that PSPI didn’t’ complete the job and some welding had to be done. I was fortunate enough to meet a local Mustang enthusiast that was a welder by trade and he provided me with a way to get the Mustang onto its side so it could be worked on without laying on the ground.

 Notisserie – Totally Average Joe!

DSCF0007To get the Mustang on its side I used what I like to call A notisserie, provided by my local friend and welder. It would be nice to have a real rotisserie, maybe one will magically show up on my porch some day.

The notisserie is comprised of six steel wheels and a length of 2.5 inch 1/8 wall square tubing all welded together to make it all work. To lift the car an engine hoist is used and then the contraption is braced with 4×4’s to keep it stable and secure.

Floor Pan Replacement

Interior_2 015The floor pan on Project Playboy wasn’t completely rusted out and I could have just patched the sections under the passenger feet but I opted to do a full replacement to keep things clean.

The inner floor frame supports where pretty banged up from being bottomed out so the decision was made to replace those while I had the welder on site; the driver side strut rod bracket was also replaced since it appeared to be bent also from getting bottomed out when this old mustang sat low in front.

03112009a 010    03112009a 016


DSCF0004One thing you may overlook when replacing a floor pan is to remove any of the old brackets that you may need from the old pans before they go to the scrap yard. You also need to measure and document where these should be placed on the new pan. The parking brake cable brackets and the back seat brackets needed to be savaged and placed on the new floor pan.


Spot Weld Remover

1780_spot_weld_smlTo remove the floor pan, frame rails and just about any other part that is spot welded together you should use a spot weld remover. Using one of these tools can make things easier and maintain originality of your Mustang since you wont be drilling big holes all over the place or cutting things up get old parts out.

 Sealing the Undercarriage


No, this isn’t the step where I apply seam sealer and undercoating, All I want to do at this stage is apply some epoxy sealer and then get back to the body shell and panel work.


Sanding the surface

I used an orbital with 180 grit sand paper to scuff the major surface and then followed up with a scotch bright pad in all the nooks and crannies. Scuffing the surface insures that the epoxy sealer has something to get a bite into, if the surface was completely smooth the sealer may not adhere to the surface and later begin to flake off. The final step is to mix up the sealer and apply it to the undercarriage.

DSCF0013   DSCF0016

There was quite a few things to finish up on the undercarriage that didn’t get wrapped up at PSPI, although I am very disappointed with PSPI in some ways I’m glad they never finished; there is less disappointment and I know that the work is now being done correctly.

3 thoughts on “Floor Pans and Undercarriage

    DONALD MONTGOMERY — May 27, 2009 11:16 AM

    I would’nt get near that contraption. Looks like it could fall on someone with a light bump.
    Bob — November 23, 2009 3:36 PM

    I have two Mustangs that are complete but because they are in Wisconsin, they are rusted beyond repair. I saw where they can be rebodied but do not know where to get some instructions on how to do it. Any ideas? Thanks
    Eugene McInnis — February 17, 2010 9:43 PM

    i have a 68 coupe 1 owner car 289 from canada it’s pretty rotted out plus has been hit the front frame rails are rusted out some better hints on repair would be great
    jim swhea — February 27, 2010 5:46 AM

    87 Monte SS. Floor is rotted everywhere. Who should have an idea, besides getting a crusher. I cut away all underlayment. Supports still in place. One thing at a time. looking to restructure support. Thanks.
    DAMON J. — October 20, 2010 4:29 PM

    Im planning on replacing the pans in my 66 coupe this weekend.
    I was woundering if it a D.I.Y job or should i take it to a body shop for installation.
    If its a d.i.y job what steps should i take to make sure that i install the floor pans correctly
    floyd — November 8, 2010 9:21 AM

    Where can I get D.I.Y. instructions for replacing the floor pans in my 66 convertible?
    Tom — August 17, 2011 1:00 AM

    Great article. Trying to find article on how to detail the under carriage. Do you know of any articles?
    The project I am working on is 1966 GT Mustang Fastback. The undercarriage has been sandblasted and primed with iron oxide. Engine compartment paint semi-gloss black.
    Gregg Snyder — May 8, 2012 11:13 AM

    I would like to know more about the Notisserie, how to build one and what the cost might be. Any help you can give would be appreciated. I have a 67 Mustang that I’m working on, thanks!
    Kermit Coble — July 18, 2013 5:51 PM

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