Mounting Bumpers - Rubber Tip Spacers

[jhjacobs]

Orginally my bumpers tips were bolted directly to the car so that it could scratch up the paint.

I am getting ready to re-install them and I have purchased the little rubber tip spacers which were missing. Mounting them is a bit confusing without a reference; my manuals are not helpful and the part book diagrams are not very clear (although they show two bolts). It appears that I must bolt the spacers to the bumper and then bolt the spacer to the car. The spacer has 2 holes, one threaded. I assume the threaded hole connects to the car with a bolt from the inside. The bumper also has a threaded hole which I assume accepts the bolt through the un-threaded spacer hole. When I do this the spacer sits flat against the car but the bumpers ride about 2-4mm from the spacers; e.g., there is a noticable gap.

Is this correct? The rubber spacers seem to be nicely molded to fit down over the bumper but the holes don't make any sense like this.
Are there different spacer types (might I have the wrong ones)?
Any reference photos would be appreciated.

 

[bert35csi]

JJ, the plastic spacers that's in your possession is for the 1973 bumper only.
Due to new bumper regulations mandated by the US DOT, BMW had to extend forward the front and rear bumpers by at least 2 or 3 inches. Basically, the front bumpers are the same between the 73 version and the pre 73 bumpers saved for two differences. The small vertical bumperettes incorperated a newly contour rubber guard. Here are some little details that pertain to your issues. The mounting brackets that mounts to the fenders are welded differently, the pre 73's were attached more closely to the surface whereas the 73 units were a little more recessed. The 73 bumpers mounting holes for the front fenders is about 2 inches in front of the attaching holes for the pre 73 cars, thereby necessitating the new spacer. It was necessary due to the different fender contour of the new mounting position.

Sorry for the long winded history on the various bumpers, but this is what you'll need for your 71 bumper. This application used a thin soft plastic strip
as a protection between the bumper and the painted fender. Its basically a small rod like strip with a small slit that has been cut in the middle. This slit is then slip into the bumper ends. This small plastic part is still available. I bought a few of them from Carl Nelon recently, they are about a few dollars each.

I bought a brand new set of front bumpers a few months back without realizing it was for the 73 cars so this where I've gathered some of my bumper infos and facts from. A quick call to the 'coupe guru', Carl Nelson assured me that the new bumper will mount to my 72 CSI with no problems. The bumper has not been installed yet. Hopefully everything will go smoothly.

Good luck JJ on your bumper project.

Bert
72 3.5 CSi
88 M6

 

[jhjacobs]

Thanks - I think you nailed this one. The bumper mounts do appear to be welded too far out as you say; otherwise it would be fine.

If it isn't one thing it is another. All last week I was struggle with a mis-bagged front window gasket. What a nightmare - fortunately it is all sorted now.

 

[jhjacobs]

I was able to get the bumpers on and secured properly. I wound up drilling the rubber tips so I could run a bolt through them. I also was able to reposition the threaded mount points in the bumper tips (with force) so that everything fits reasonably well.

I fashioned some underlay cushions and bolt covers for the rear bumper using black mouse pads. While not authentic it worked well and it is invisible to the eye. I wound up cushioning the entire mounting area to prevent direct contact with the paint.

I must say the two lower mount bolts on the rear bumper are quite unpleasant. It is on the limits of human capability to get fingers up between the fuel tank and rear body panel. I suppose I could have removed the fuel tank but that would have been cheating.

Thanks for the helpful information.

 

[bert35csi]

JJ, it's good to see that you've mounted your bumpers. I've uploaded some reference pics anyways.

Plastic barrier strip fitted on 72 bumper.

New 73 bumper with barrier strip installed.

Underside of bumper with barrier strip, notice strip needs to be trimmed for exact fit.

Spacer for 73 only bumper.
[Broken External Image]:http://bmwfans.info/original/images/19512_p.png
#2 is the desired part. Part # is 51-11-1-811-180

 

[bert35csi]

JJ, I've a question about the reassembly of the rear bumper. With its limited access, did you have any difficulties in reattaching the two bolts that are underneath the chassis, right next to the gas tank and rear wheel well.

Thanks
Bert

 

[jhjacobs]

Thanks for the photos. At some point I may go and purchase the correct underlay material but, as I said, I abused what had to make it work for now.

With its limited access, did you have any difficulties in reattaching the two bolts that are underneath the chassis, right next to the gas tank and rear wheel well.

No problem at all. I took a 16oz hammer and flattened my hand a fingers so that they could reach up in there.

Seriously, the one behind the spare tire isn't too bad but the one behind the gas tank is inhuman. I was just able to reach the one behind the tank with the tips of my fingers, I got lucky and got the bolt started on the 15th try! The real key for me was a flex-head, ratcheting box end wrench set I picked up at Harbor Freight:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93791

This is a great excuse to buy some nice tools. Perhaps we should start a thread on coupe projects that can justify the purchase of tools along with the proven techniques to explain it to our spouses!