Bumpers

The bumpers on the car had gotten mounted by someone who didn't know what they were doing.  There was no U-shaped rubber between the overriders and bumper, and the escutcheons that cover the bumper strut hadn't been put on.

So I removed the front bumper to fix these problems.  The PO had made new T-shaped pieces that attach to the bumper and fit into the struts.  However, the holes weren't exactly in the right places so I had to pry off the bumper thread by thread.  I'll relieve the holes as needed so the bumper will fit on easily before I reinstall it.

The next thing was to dig out the escutcheons and figure out which one fit on which corner.  It turns out that I seem to have three for the front and perhaps one for the rear (I won't know if it fits until I remove the rear bumper).  The first problem was the paint on the strut.  I had to remove most of it before the escutcheons would fit.  After that and removing a couple of bumps on the struts, I got two of the escutcheons to fit.

Now I have to glue the U-shaped rubber on the body side of the escutcheons and the overriders, but I'll have to continue on another day.

Fitting the U-shaped rubber just takes time.  For this project, there are two sizes, a small size for thinner metal like the escutcheons and a larger one for the bumper overriders.

For round objects, I carefully cut the rubber to length and glue the two ends together with instant glue.  That prevents the ends from wanting to straighten out and pull away. 

Once that is done, I clean the glue surface on the rubber with lacquer thinner to remove any of the mold release used in making the rubber.  Then it's a thin coat of rubber cement on the rubber and metal where the rubber will cover it and after a drying time, stick the two together.  One always ends up with excess rubber cement so you have to clean it off with paint thinner.

The PO had made new T-shaped pieces to hold the bumper to the car, but they didn't fit very well.  I spent an hour or so adjusting them and lengthening the holes with a Dremel to try and get the bumper to slide easily into the struts.  I finally got frustrated and quit for the day.  Tomorrow will be a new day and I will start with more patience so hopefully will get the front bumper completed and on the car.

I ended up taking the pieces back to my neighbors and used a 1/2" end mill on his big drill press to lengthen the slots.  Then everything fit after bending one of the arms so that end of the bumper would align with the side hole in the fender.  I don't have any rubber pads to go between the fenders and the bumper ends so that still needs to be done.  Actually, I do have pads, but they are on the 330.  Pininfarina used special pads on the 330 and I finally I got the correct ones, but need to install them so I can use the old ones on the coupe.

After getting the front bumper to fit, I took apart the rear one.  At least the T-shaped pieces fit better back there.  The rear bumper is a three piece with a center section and two tips that fit along side the fenders.  For now, I just took off the center section which had the overriders attached to it.  One thing I inherited with the car was a dent in the lower side of this center section.  From the location, I think that it got dropped onto a sharp surface after the re-chroming.  The chrome surface was fractured, so it will need to be chromed again, but I spent some time trying to minimize the dent until then.  The left picture is the before, the center is where I was using a slap hammer and a sand bag to remove the dent, and the right one is after I was done.

Then I attached the rubber pieces to the overriders and after polishing everything, got the center section ready to install.

One other thing I had to do was to drill and tap holes in the T-shaped pieces to accept a bolt that tightens those pieces in the struts jutting out from the car.  The PO had done this on the front pieces, but used 1/4-20 thread bolts and the holes weren't in the right places once the escutcheons were installed.  I used a 6x1.0mm tap so those bolts would be metric.

One thing that I noticed was that the inside of the overriders is stamped with a PF body number of 161.  Since 849 is the body number for my car, these bumpers must have come from another car.  According to Hilary Raab's red serial number book, 161 belongs to a series 1 coupe, 1365GT.

I needed the rubber pads that fit between the bumpers and fenders.  These are just plain pads about 2" in diameter and 3/4" thick.  I had used similar ones on my 330 GT many years ago.  Since then I found out that there are special pads for the 330, so after I got them, I put them on and now have the plain ones to use on the coupe.  I also sand blasted the T-shaped supports and primered and painted them.  Once they are dry, I'll be ready to put the bumpers on in final form.

I put everything back together on on the car.  The pads worked fine in the rear, but needed an additional piece in the front.  The front fender curves away from the bumper, so a flat pad doesn't work well.  I took a piece of 3/8" thick piece of rubber and cut a 2" diameter disk and then sawed that disk on a diagonal, so I ended up with 2 wedges with no thickness on one side and the full 3/8" on the other.

I glued each wedge onto a pad and then oriented it so the thick portion was below the fender where it curved away.  You can see the before and after.