Rear Bumper "Finisher" Delete

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Delia

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There is a '74 3.0CS project in our shop that is getting a '73 bumper conversion. Since the rear bumper "finisher" part (in the center at the seam) is unavailable, we're planning to do a "smoothie" one-piece variation, welding together the two halves and chroming the entire piece.

As you know, the two bumper sections are held by the "finisher" a certain distance apart. In order to fill the gap to create the one-piece bumper, I need to know the distance between the two.

Has anyone done this? Do you know the dimension?

I apologise to the purists on the forum.

Delia
 
Hang on,
the original set up is by means of an overlap, hence the special screws with a square section for the first 7mm of the thread. I would not attempt to cut the original halves.....
I would spend some time searching for the overlap part.
If I remember correctly there´s one for sale on Ebay Germany under BMW e9....

Good luck !
 
I appreciate your concern, and as I mentioned, my apologies to the purists.

This one's "not my call," so if you could indulge me with an answer to my question, I'd be most grateful.

Delia
 
Delia:

I'm not a purist, and frankly, I think the e9 would look cleaner without that trim piece. However.....

Expecting a single dimension to be correct for all e9's is pretty optimistic - BMW built these things in low quantity, pretty much by hand. One of the reasons for designing the rear bumper in two overlapping pieces was to allow each bumper to be individually fitted to give consistent gaps. If I told you that the "gap" (of course, there is no gap on an overlapped seam) was .2311" on my car, that dimension would probably be irrelevant for your customer's car. Especially after 35 years of rear-enders.

If your customer is committed to going the "smoothie" route, my suggestion is to fit the bumper halves to his car's body once the bodywork is complete, and to tack weld them while mounted. Note that the two-piece design allowed the bumper to be adusted in the fore-aft dimension, as well as in width (in other words, how deep/shallow of a "U" the bumper makes when viewed from above). Frankly, I think it's going to be tough to get the gaps right doing it this way, and that the number of hours consumed will far outweigh the time/expense of finding and installing the trim piece. But hey, the customer is always right.
 
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Rear Bumper

Delia,

The finisher doesn't hold anything together, it merely covers the carriage bolts that holds the two pieces together, one bumper fits inside the other. Without the finisher you would see the upper and lower bolts. Look in RealOEM for the diagram.
 
The long rubber part and the screws pretty much holds it together, so that it can be moved around in one "steady"? piece.
Have done that many times before actually mounting it.
 
Just a quick thank-you and a brief update...

I took the pieces down to Superior Chrome in San Jose and discussed the project with the guys down there. I was buoyed up by the fact they recognized the bumper bits as being from a CS coupe so I discussed the possibility of having them make a smoothie bumper.

There were several concerns:

1. Overall strength of such a long piece being able to hold together without cracking/breaking at the weld.

2. The precise "bow" of the bumper and where/how it would attach to the rear quarters. Too much/too little would not be acceptable (as mentioned above)

3. How to make (if necessary) a "finisher" cover in the manner of the NLA factory part.

They will get back to me in a day or so.

Meanwhile, I logged on to German ebay and put in a bid on the correct, NLA "finisher" part.

Again, thank you all for your help.

Delia
 
Delia:

Did you see nyccsi's post, where he mentions Carl Nelson at La Jolla Indepenent? Check out www.bimmerdoc.com for contact information. Carl parts out CS coupes, and is likely to have a rear bumper finishing piece. That German ebay auction might also be a source, but La Jolla is a lot closer to San Jose.

Another source would be to place a "Wanted to buy" message in the "Parts" section of this board.
 
As the writing in the ebay offer is in german, perhaps I should point out that the buyer states that the part is covered with small hairline cracks of old age.
 
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