I've been beating my brains out trying to fit a new fiberglass front bumper on my 75. Seems like no matter what I do, it just won't fit. I have some very specific questions, and hope that some of you have done these and can tell me what I'm doing wrong?

1. The factory retainer strips were very difficult to place in the bumper. I had to flatten out the inside of the mounting areas a little before they would fit. The side ones would not go because of the shape of the bumper, had to notch the holes so they would fit. I would have to assume the original urethane bumper was flexible enough where these would fit okay?

2. The bumper won't tighten up to the body. Even with the nuts fairly tight (didn't want to go too much, thought they might break) there is a small gap on drivers side, and nearly a 1/4" gap on the passenger side. I haven't been able to get many of those nuts started yet.

3. I read a recent post that someone mentioned the honeycomb insert has to be removed for a glass bumper to fit. This might explain why I'm having such a tough time, and things are going to get a lot worse if I start removing material from the bumper to get a tight fit to the body. Is it true the honeycomb needs to be removed, or does it need to be modified somehow? If it were removed, how can I mount the big center "pad" because it sandwiches on the front side of the honeycomb?

Any help you people can offer here would be greatly appreciated! :eek:

 

Also, block the bumper installed to be sure you get it smooth in the installed position, I didn't and when I installed it and tightened up the nuts, the cover warped a tad at each corner. Not noticable to most people, but I know it's not perfect. GOOD LUCK! :cheers:

 

Yeah I know what ya mean.I have installed alot of those bumpers.Usually you have to pre fit them and fill the gaps and uneveness with some fiberglass and body filler.Now you know why it is so expensive to have bodywork and paint done. :yesnod: :seeya

 

74-Roadster covered well the first 2 question and I try to give the third qestion a go.
I'm doing this same thing on my 79 and I just got rid of both, the honeycomb and the big heavy pad. The fiberclass bumber is tough enough as is to mount th front licence plate etc. And that pad and honeycomb are just for the 5mph impact, when using fiberclass, it'll crack anyway, so no need to use that pad anymore... :cheers:

 

I am doing a fiberglass bumper on the front of my 75 right now. The instructions say the honeycomb must be cut down, I left it out. The 2 braces in the center of the car running back to the vacuum tub also interfer. My bumper fit fine on the drivers side but on the passengers side was about 1/2 inch too short. I had to cut the bumper in two, attach it to the car then refiberglass back together. I also had to fill in alot on the passengers side to get the gap closed.
It is not a simple bolt on deal and I believe it is not the pumpers problem but the fact that the bodies are not all the same.
Good luck

 

I removed the honeycomb on my '75 when installing one of the Truflex bumpers. I also had trouble with the stock retainers but managed to get them in. At that point the only way to close the gap (1/8 -> 1/2)was to crank the hell out of the nuts and I didn't want to leave the fender in such a stressed condition, so I ended up filling the seam with epoxy and cutting a faux-gap with a hacksaw blade.

 

If you look at the inside of the bumper I'm sure you will NOT see the Ecklers brand name. Ecklers bumpers fit PERFECT! (at least mine did) I bought an Ecklers front bumper and also a rear bumper from ACS Glass (I don't know who they are either cause I ordered it through a vette shop). The front bumper did require sawing the holes into slots on several of the holes (not all), because the original bumper was flexible rubber and the lip could be folded back to slide the bracket under.

The Eckler's bumper slid right in and matched right up...no filler or shifting it around required. The honycomb stayed where it was.

I was not so pleased with the non-Eckler's rear bumper. The rear bumper (ACS GLASS) required that I remove the tail lamp brackets, and grind away material from the bumper reinforcements, and add about 1/4" of filler to one side of it...a very poor quality POS! I was in a hurry to finish it, but if you have the time, then send that non-fitting bumper back to where-ever you got it and order one from Ecklers...I got the "flexi-glass" bumper which has a nice smooth outer skin with the rigid fiberglass reinforcement inside.

Hope this helps.

 

Mine came from Ecklers's. I'd say you were lucky!

 

Mine too, says Eckler's on the back...

 

I appreciate the help everyone has been here. I just came back from a visit to my body shop friend, and I would like to share with you what he suggested. Try bolting or clamping the cover where you want it for best fit, then glass it to the car. Before the glass is totally hard, use a razor knife to cut the bumper away from the front edge of the car. Remove and then build up the bumper a lttle over the top of the "new" edge using glass mat and resin. Then with only a little light grinding or sanding the bumper should fit perfect. Bolt the bumper back into position and sand the whole assembly to blend perfect with the front end. He uses a DA with 36 grit, then blocks and sands to smooth out everything prior to priming and final blocking. He said the whole process sounds difficult, but it's not really all that bad once you get into it. I'm going to tear into this today, I'll let you all know how it came out, hope this might help some of you with the same situation. :skep:

 

Weird, mine was just the opposite. we had to work the ecklers bumper like hell to get it to fit right. All the ACI stuff i got fit great. i was actually very impressed with ACI. i guess you win some, you lose some?

 

You know, I'm completely convinced that fit with after market bumpers is a crap shoot at best. There are so many variables, like the cars being mostly assembled by hand could cause some variations, and body repairs done to the car can cause major variations. I know mine was hit in the front end, and the drivers side must have got the worst of it because that is where the largest gap is. The passenger side also has a substantial gap, but I think this repair and fitting method I described above will work pretty good. All in all, the bumper didn't fit too bad, the top seam is pretty reasonable. Mine was made by American Sports Car Design, I understand they are out of business now?

 

You didn't mention where you purchased the bumpers. I orignally bought front and back for my '79 from Vanacor and neither came even close to fitting. The quality was crap and the guy that owns the place is a jerk. I sent his junk back and he charged me a 15% restock fee. I then went with ACI and they fit like a glove. The customer service was outstanding also. It is true that most Vettes have some degree of body variances, but a good quality repop should at least come close. I used the little stainless steel retainers as previously mentioned and I removed all honeycomb bumper material and the plastic tail light housings that attach to the big metal bumper on the back. Good luck....

 

My 75 came with an Eckler's rear 'glass bumper.
The Aluminum reinforcemnets in the back had to be removed to fit.

... the front remains to be seen. You guys are scaring me.

BTW - only a few bolts to get the honeycomb out of the way for a test fit.
:seeya

 

"Ecklers bumpers fit PERFECT!"

Both of my bumpers are from Ecklers; the rear one fit pretty well, but the front is so off it's not even funny. The entire angle is wrong, so no matter how you have it, one side is always two inches away from the body. We're still working on it here and there, between other stuff.

We also put down a layer of fiberglass behind the rear bumper to strengthen it, and will do the same with the front. It seemed flimsy, like it would crack if someone leaned on it. Of course, nobody will be leaning on my car... but in case someone does when I'm not looking. :D

Jerry

 

You guys are on the money - these bumpers fit every car a little different. The key is massaging the bumper to fit the car. Here's my routine:

Front bumper - Remove honeycomb and center plate. You may be able to reinstall later, particularly by trimming the honeycomb and grinding the inside "bumperette" area of the new bumper so it will slide over that center plate, but I left mine off. Use some large squeeze clamps with those rubber tips on them (Home Depot) to carefully position the bumper for best fit. You'll probably be able to get a great fit across the top and on one side. The other side (usually the "triangle" at the corner) will have to be re-glassed for an exact fit. You should be able to use the stock retainers or stainless bolts, nuts and washers. You really don't need the retainers to spread the load as the bumpers are plenty strong. As a matter of fact, I would rather the bolts pull through on impact (perish the thought!) than wreck the fenders. Used a fine point sharpie to carefully trace the bolt holes (elongated already) and remove the bumper. Start the holes with a drill and finish by elongating with a "rat-tail" file or a carefully guided "Roto-Zip" (works great!)

Rear Bumper - Similar to above, except remove all shims on brace, remove tailight plastic supports, and re-use metal tailight retainer rings sandwiched around bumper to retain tailghts. (I also removed two corner braces on impact bar)

I use ACI exclusively - great products, service, and specials at Carlisle.
Hope this helps.
:smash:

 

In case anyone is interested, here's how I finally got the front bumper cover to fit. First I glassed the mating edge up and got it close, best I could. Areas of the outside and inside of the bumper were built up for strength and more than expected grinding or fitting. Then I taped wax paper to the front fenders and hood mating surface. I laid glass mat on the bumper with resin, then clamped it in place. The mat and resin kind of oozed into molding the bumper for a perfect fit. I will the remove it for final detailing and installation of all the bumper hardware components behind. I'm still not sure whether I will get the honeycomb to fit, but would like to for increased safety. This is a link to the final fitting photo of the bumper:
http://home.earthlink.net/~steverieb...s/vette37s.jpg

I Sincerely hope any of you doing bumper covers don't have the fit problems I had, but as long as you keep at it things will eventually work out. Sorry, I just fixed the link problem to the picture.
:cheers:


[Modified by Big Fish, 11:44 AM 1/4/2003]


[Modified by Big Fish, 4:45 PM 1/5/2003]

 

Since I am in the process myself of doing the front bumper on my 79, what did you use for the filler to build up the sides to fit? I have a flex glass cover that I just got and laid it up against the car and it will need to be built up some on the ends. I'm also considering just filling the gap and making it seamless while I'm at it. I will try taking the honeycomb off to see if that helps the fit too, but it actually isn't too far off now.

 

Mobile; this thread is from 2002.

 

And he is asking about flex bumpers and in multiple forums... Holy dead thread revival batman...