It became clear as we began the disassembly of our 1976 Datsun 280Z that we were going to have to strip it down to the bare necessities in order to deal with our rust issues. The lesson learned in this is that for every place you see visible rust on your car, there’s probably another 60% or more you can’t see. Here’s our list of trouble spots:
- Frame rails
- Driver’s side hood mount plate
- Lower front section of both quarter panels
- Hatch windows frame
- Fuel door area
- Floor pan
Most of our rust problems were the result of a previous restoration. What were probably minor rust problems at the time were made worse by taking shortcuts on body work. In the case of one front lower quarter panel, someone had shoved bondo into a rust hole until the cavity behind it was full then sanded it down. Not good! This time around we’ll take care of the rust the right way.
I already talked about our Datsun Z-car frame rail solution from Bad Dog Parts in a previous post (link). Here’s how we dealt with the rest:
- Hood mount: This is the kind of repair where our ‘74 Datsun 260Z parts car has proven invaluable. In this case we were able to “borrow” the needed, pre-formed sheet metal portions from the donor car (it’s not getting them back :-). We used a spot-weld drill and sawzall to remove this section from the 260Z intact and then used this piece to replaced the rusted part in our 280Z. We re-welded the new part in place using a halon MIG welder, placing our welds in the same holes where we drilled out the previous spot welds.’
Original hood mount rust damage
After replacement panel installed
- Floor pan: There were only a few, small trouble spots in the kick panels on both sides. We removed all the rusted panels and replaced these with new sheet metal, MIG welding them in place.
- Quarter-panel sections: These were no good in our parts car so we had to bite the bullet and purchase ’70 – ’78 Datsun 240Z / 260Z / 280Z patch panels from Motorsport Auto. The fit was decent but it took some coaxing to get these in place perfectly. We created tabs where the new patch panel met the old quarter panel in order to create a tight, water-proof fit.
Quarter panel after removing rusted area.
Quarter panel after installing patch panel.
- Fuel door: This one’s too tricky to fully describe here. Suffice it to say that we fully disassembled the fuel door and separated the two layers of sheet metal in the area surrounding the door in order to remove all the rust. Then we welded the parts back together with a new piece of extra sheet metal around the fuel door on the inside of the quarter panel for added strength.
Fuel door opening ready to weld.
Fuel door after re-fitting and welding.
In all cases we used a wire grinding wheel to remove all the rust we could from our stripped parts and then applied a high-quality rust converter to completely neutralize any that remained. After welding the new parts in place, we used seam sealer around them to ensure no water could make its way between the new sheet metal pieces. Finally, we used several cans of Eastwood’s Internal Frame Coating spray system to coat the inside of our new parts, frame rails, rocker panels, quarter panels, door posts, etc. with rust inhibitor.
Coating all internal surfaces with rust inhibitor.
One of the hundreds of decisions faced by those looking to restore a Datsun 280Z is what to do about bumpers. Starting in ’75, Datsun had to meet new US crash-test rules with the result that 280Z bumpers weigh more than I do and are twice as ugly. To make matters worse, all the rubber parts for these gems are hard-to-find and expensive. After the nearly $1,000 in rubber parts and another $600 or so in chrome repair, you’re still left with a set of bumpers that look like something off a ‘70s-vintage Cadillac.
What we're starting with.
I presume this is why you see so many 280Zs either fitted with body kits that replace the bumpers or retro-fitted with the smaller-style bumpers from earlier Datsun 240Z and 260Z models. Not only are these solutions much less expensive and better looking, there are a wide range of manufacturers with various adapters and other options to fit your needs and style.
As for us, we’ve decided to refurbish the smaller-style bumpers that came with our 1974 Datsun 260Z parts car. Though we haven’t installed them yet (more on this later), it appears that we should be able to adapt the 260Z bumpers and shock mounts to our 280Z with some minor modifications. I’ll fully document how this works out when we get to it.
Clearly this solution isn’t the best or only way to deal with your Datsun 280Z bumpers. Purists would say we aren’t doing an authentic restoration because we’re not using original parts, blah, blah, blah. For us it came down to this: We can’t see spending so much money to restore bumpers that we don’t like in the first place. When a solution that looks better is also less expensive, it’s hard to argue. We’ll see if I still feel the same way after we get them installed.
One of the many things I learned from Gary (the machinist who rebuilt our motor) is that with original vintage Datsun Z motors and transmissions, the original parts are much higher quality than most new parts you’d buy to replace them. For example, the original Z motors came with forged pistons, which means in almost all cases you’re going to end up with a stronger motor by using the old pistons with new rings than buying the cheaper, cast pistons available in the aftermarket. The same general rule applies to the crank and many other engine parts. In the end we’ll pay about the same amount we would have paid for an off-the-shelf motor but we’re going to know that everything has been fixed first-rate.
With our engine and transmission, “in the oven” so to speak, it was time to dig into the rest of our 280Z. Not surprisingly, after stripping out the interior and starting to remove body pieces, it became clear our rust problems were worse than originally thought. The driver’s side floorboard was rusted through and the driver’s side fender is like swiss cheese. Both will have to be replaced. However, compared to other Z rust horror stories, I’m still feeling lucky.
Our next research item was frame rails. Ours were no longer sound, to put it mildly. Our first thought was that we were going to have to drill out the spot welds on the old ones and buy replacements. This was the job that had us quaking in our boots (a little). Once again turning to the trusty ZCar forum and doing a few searches, a name came up with an ingenious solution: Bad Dog Parts . The proprietor, John, an obvious Datsun Z-car nutcase, fabricates brand-new frame rails that fit neatly over your old ones and are then welded in place. Genious! They’re twice the thickness of the original frame rails, providing a solid, good-looking fix that appeared to be an easier solution than taking the old rails completely off.
In our case, getting these rails on was a little more tricky than originally planned. Both our frame rails were not only rusted out but dented in, with the tops of the old rails mushroomed out, making it so the new ones wouldn’t fit over. Overcoming this required cutting away the bottom half of the old rails with a saws-all. It wasn’t all that hard but it caused us to wonder if it would have been just as easy to replace the complete rails rather than use the slip-over solution. It seem like if your rails are just rusted, the Bad Dog rails are a great solution. However, if your rails are damaged and rusted, you might consider replacing them entirely. The other problem we faced was that the rusted-out floor panels were right above the frame rails. To do it right, we had to first repair the metal on the floor so we’d have a solid surface to weld the new frame rails to.