Z floor pan replacement

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Z floor pan replacement

Postby gmac708 » Mon Jun 08, 2009 6:28 pm

I recently replace the floors in my 1970 240Z. I used the Zedd findings floor panels and the Baddog parts frame rails. Both are quality manufacturers but they do not supply the finished product. It’s more like they supply the raw materials, and you supply the “fab” skills. I recently purchased a MIG welder for the task. Originally I had planned on purchasing a used welder, using it for the project, selling it for what I paid for it after I had completed the repairs. Makes sense. I could not find a good used welder until I purchased a new one (figures), and now, I won’t sell it (probably why there were so few for sale). The people I talked to said get the MIG over TIG. Less temp, better for bodywork.

Again…most of the pictures are of the drivers side. I completed the passenger side earlier.

I elected to replace the original frame rails with the Baddog frame rails. You could do both, or just the original frame rails, your choice. My originals were beat to crap and I can only imagine how they would fit. Here you can see that they fit the cross section perfectly.

Spot weld removal. Every spot weld must be drilled out…

…pried apart…

…leaving this (notice I made a boo-boo and drilled all the way through)…

And this… which is later ground down flush with the base sheet metal.

OK. Seat brackets are out.

Corrosion is in red, cut on green line, remove spot welds along blue line.

Here is detail of front looking outboard.

From below… You get the idea

Purchased a “nibbler”. Works great. Otherwise, I used hand shears.

Floors out. Notice I did not have to separate the old frame rail from the floor. It was because I had cut it off at the firewall. You can see what is left over sticking out.

Here is what is left over on the back. Notice gusset in the aft rear corner. This required a few extra “son-of-a-b****es” to find all the welds.

Another view of up front.

Here is new rail going in.

Cut-fit-cut-fit-cut-fit…you get the idea.

Notice the red line is the separation of the old floor and the door sill.

The floor is starting to fit in much easier. Take your time and don’t rush. Sneak up on it.

Now roll the edge. This bead rolling tool is a leftover from the FMIC tubing I used on the 240SX. Makes a nice edge.

OK…I used these funny little things called “cleco’s”. They are used in the aviation manufacturing industry. They are used to secure sheet metal together. I’m sure you could use PK screws as well, but these keep spring tension on the area and are easy to use.

Inside edge fits good…working along the front edge

Along the back…

…along the outside edge. Remember to take your time and trim off a little bit at a time.

This is the Badd dog seat support. It did not follow the contour of the floor, but it was flat where it needed to be. I had to trim and grind the radius on the inboard side too.

Everything is flat.

Time to start welding! Start off by tacking around, using a criss-cross pattern. Do not stay in one place. Move around.

One you have several welds located it the same area, you can use a hammer to stretch or shrink the metal together.


You will be done…with the welding. I still need to attach the rear seat brackets and apply the seam sealer, but you get the idea. I learned a lot, burned the crap out of my skin welding upside down, but I did have some fun. Make sure you measure everything several times. Did I mention to take your time?I will post up pictures on the Bad dog frame rails soon, now where are those seats brackets….?

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Re: Z floor pan replacement (gmac708)

Postby boro drift » Fri Jun 12, 2009 2:19 pm

Well done Gordon. Makes me wish I had bought that Z a couple months ago I was looking at. Now it's gone.

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Re: Z floor pan replacement (boro drift)

Postby NSR_s30 » Sat Jun 13, 2009 3:29 pm

Want to do my floorpans? You make it look really simple my friend. You did a great job.

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Postby evildky » Sun Jun 14, 2009 4:44 pm

why didn't you take the pans to the pinchwelds?

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Re: (evildky)

Postby gmac708 » Mon Jun 15, 2009 4:44 pm

evildky wrote:why didn't you take the pans to the pinchwelds?
I centered the floor "bump" on the frame rail. Not really much room either way to move off center. I was having troubles getting the outboard edge to stay level, flat and square using the provided or pre-fabricated bend. I figured the old floor on the outboard side met all three requirements and was really solid. I cut the provided bend off, and everything started to fit better. I hope that helps.

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Re: (gmac708)

Postby bigred240sx » Tue Jun 16, 2009 5:13 am

nicely done. i need to do mine but i dont have the time or the patience. i would end up rushing and screwing it up.

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