Removing BC Coupe taillight lens?

[Redline]

Sorry for the rather dull question, but is it correct that I need to first undo the two knurled nuts from the back side of the taillight assembly in order to remove the lens and change a bulb? First time I've had to change one, and I have no owner's manual.

[DUCeditor]

Assuming the coupe uses a similar method as the Spider, yes. And once the elongated bolts are removed the lens(es) come free by swinging them away from the ends that have tabs.

On my `77 Spider the gasket material was so badly deformed and disintegrated that it appeared to have been merely white goop squeezed on out of a tube. But in fact it was a formed gasket made of white foam material, since replaced.

Be prepared to clean the reflectors and lenses. Glass cleaner or well diluted ammonia with a drop of dish detergent shod do the job.



-don

[Redline]

Thanks

[kmead]

Yes the knurled knobs inside the trunk need to be removed which allows the chrome bar to move outward which frees the bottom of the upper lens and the top of the lower lens. There are tabs that engage the tail light body on the lenses and corresponding slots in the body of the taillight.

A little petroleum jelly makes a good sealant into the old foam seals. Not gobs, just a thin layer applied to the back of the lens where it contacts the foam material.

You don't have the upper amber/orange lens on yours do you? I have always wanted to change over to those (same part used on some Lambos from the same period).

[Redline]

Yes, I tell everyone that I drive a Jarama.

[ace124]

Yeah and i a Lamborghini Espada or an Iso Revolta

[Redline]

I guess the bulbs hadn't been changed in years, as one of the bolts snapped off. Time to find a creative solution now to put it back together; drill and tap the bar to hold a normal long M4 bolt?

[kmead]

Bummer. I should go have a look at mine. That is going to be a fussy part to fix as its likely a zinc casting.

[DUCeditor]

I guess the bulbs hadn't been changed in years, as one of the bolts snapped off. Time to find a creative solution now to put it back together; drill and tap the bar to hold a normal long M4 bolt?

I made a replacement for mine quite simply, I found an appropriate nut and epoxied it to the end of a hollow metal tube of sufficient interior diameter to allow the threaded 'bolt' section to pass through unimpeded.

The parts were easily found at a local hardware store's nuts, bolts, and doohickey aisle.

-don

[Redline]

The threaded rod snapped only about 6mm (1/4") from the bar, so not enough left to fit through the clearance hole in the tail light assembly and engage a nut.

Is it not possible to drill and tap the zinc casting to take a blind threaded hole for a M4 machine screw? We have a machine shop at work, so alignment and good cutting tools / oils is not a problem. Is zinc too brittle for tapping?

[kmead]

You should be fine. Castings are always a bit difficult. You might be able to weld an additional piece of metal to the stub and turn out the existing piece. Its worth trying.

I doubt they over cast the bar over steel threaded parts so they should remove.

[Redline]

In the end it was no problem. Drilled and tapped the boss on the bar, threaded in a new M4 stud and cleaned up the threads on the knurled piece. Good as new. Despite the small problem with corrosion (it is 40 years old), it's a really nice design and a lot of modern cars could learn a lesson in ease of replacing bulbs.