Rear Bumper tube support End Removal

[carl]

Once you remove the bumpers on your X, you are stuck with the bumper tube supports sticking out. Most of us just leave the rubber boots on and leave it at that. On the front I have round Hella fog lights bolted to my supports and they get hidden. On the rear though, they just sit there and stylistically aggravate me. Soooo, I decided to remove the ends that stick out beyond the body surface so I can just attach a flush mounted panel to hide the mess. Of all the power tools I had, it seemed the 4.5" angle grinder with cutoff wheel was the way to go. On TV, the custom car techs are wizards with this tool and can do anything. With me, not so much.

A lot of collateral damage but nothing that can't be fixed. Also, the repair panel will hide a lot of this even after the Bondo fix. Yes, I am welding up the slice I made on the driver side. A steel ruler indicated that it's all cut back behind the rear panel. I was going to try welding in a patch panel but I need access to the tube to slide in the bumper tubes when I need a hook up point for the engine hoist to get the rear of the car high enough to drop out the motor if need be. I'll pop rivet in the panel, it's OK, it fits with the tone of the car.

 

[Dr.Jeff]

When I removed those bumper mounts (front and rear), it was a mess. I wanted to cut them out as far inward as possible, removing as much of the no longer needed metal as possible. That was a mistake. For one thing they consist of multiple layers of sheet metal coming from every surrounding panel and overlapping one another. Furthermore much of it goes into tight recesses that the cutting tools cannot access. I used every tool in my vast selection and still made a royal mess that will require a lot of repairs and patches to make right.

For anyone that desires to do this, I'd highly recommend doing it the way Carl did here. Only remove as much from the outside as needed to make them flush. Trying to remove any of the material beyond that gets extremely involved. Granted I was able to get rid of a lot of unwanted excess metal. The idea for doing that was two fold; reduce weight, and clean up the appearance. But the weight difference really isn't that significant, and the appearance of the resultant damage is worse than leaving them in.

I'll be patching over mine and finishing it to make the holes completely disappear. That means finding another method of raising the rear of the car when doing engine swaps. I think I might add a couple of small tabs inside the trunk on either side (where these bumper mounts were) to allow lifting chain attachment. But that's just my preference for cosmetic reasons.

 

[Jefco]

One of the things I miss about Stingray 250's deleted thread was his innovative (to me) wooden bumper blocks painted with bedliner; I thought they were a great solution to empty protruding tubes; sorry we can't see them anymore.

 

[Dr.Jeff]

I've gone back and forth on various bumper ideas. I really like a shaved body with no bumpers, marker lights, extra holes, trim, etc. I also like the small Euro style bumpers in chrome, but I think I'd make custom ones a little different. The "rubber blocks" were used by a lot of Euro car makers in that era to meet US safety standards inexpensively. So at that time I viewed them as a cheap shortcut by the manufacturers and did not like them in general. Unfortunately that sentiment still remains for me (only a personal opinion), but it is a good option otherwise.

 

[Bjorn Nilson]

When I removed those bumper mounts (front and rear), it was a mess. I wanted to cut them out as far inward as possible, removing as much of the no longer needed metal as possible. That was a mistake. For one thing they consist of multiple layers of sheet metal coming from every surrounding panel and overlapping one another. Furthermore much of it goes into tight recesses that the cutting tools cannot access. I used every tool in my vast selection and still made a royal mess that will require a lot of repairs and patches to make right.

There is another method that doesn't create much mess and damage but requires a little bit time and patience:

Start with cutting the mount from inside all way round with a Dremel

Then use a cutting saw to split the bottom end of the mount,

And it will look like this. Now there's room enough for the last step...

Cut the flat part like this, -No damage on panels, even no need for repaint unless you want it a little bit cleaner...

A towing strap is nice to have. The old mount tubes can easily be temporarily set back if you need to lift the car for an engine swap etc.

 

[beezee]

Sweden 1
USA 0

Sorry, I just couldn't resist...

 

[DanielForest]

And Canada remains neutral...

I have to admit Bjorn method is much more elegant!

 

[Dr.Jeff]

There is another method

Very clean job Bjorn. In my case however I was cutting MUCH more than that out - I wanted to remove all of the box structure leading up to those mounting points, not just that last 15mm or so. But like I said, it wasn't worth it. Your approach is much better.

One comment I will make has to do with Dremel brand tools. I haven't had much success with them; I've had three burn out or otherwise break. And I rarely used them, plus never for anything this heavy. The last time I bought a different brand of this type tool and so far it is holding up much better (in your picture yours looks to be another brand as well). I don't know what it is with the Dremel brand, but they have proven inadequate to me, despite costing more.

However regardless of brand, I think it would be very slow to cut through this thick of metal with these small cutters? I tend to be ADD and HAD, so I'm not patient with slow tools.

And Beezee you are right. Some of the best metal fabrication I have even seen has been from Sweden. I guess having to keep inside the garage for 10 months of the year gives them plenty of time to practice?

 

[dllubin]

I'm using a Dremel tool that my Dad bought in the 60s. I think it was the original model. The only thing I don't like about it are the different size collets needed to hold the different bits in the chuck. The collets have three spring like fingers that like to break off. The newer ones use a much different system. I had a much newer one but it burnt out. I guess they don't make them like they used to.

 

[Bjorn Nilson]

I did not use a real Dremel. I find the Dremel weak and too pricy. I have a 19$ Multi Tool from "Biltema" wich is much stronger and durable than the Dremel. Unfortunately it's available in the Nordics only. It also has very durable cutting blades. -It took me approx an hour to cut all 4 mounts and just 2 or 3 blades. This thing has certainly become one of my favorite weapons in the garage. It is very handy for cutting, grinding and polishing small details.

And yes, our climate allows us to spend a lot of time in the garage, but it is not as bad as you think.

 

[carl]

I thought about using my Dremel. The metal there is thick and the reinforced cut off wheels are not cheap but I probably should have gone that route anyway. I just aimed my angle grinder wheel in about a 45 degree angle and that got me just behind the panel. I also cut the pieces in section using vice grips to grab and flex sections till they came off. I was going to use my air cutter but the blades seem to be a lot thicker than the ones on my electric grinder and took forever to cut through...and it didn't have the torque to get the job done.

I had also thought about cutting the tube from inside the trunk but as Doc noted, it's a very complicated area with everything connected.

Plan is to weld in a patch panel in the lower slot where the tow hook was and make a removable rectangular panel where the tub came through.

Making a lift chain attachment point inside the trunk is another great idea. Any rear hook attachment for a flat bed would probably be on the rear A-arm.

 

[Bobkat]

The tow hooks are so handy on these things. I am torn on what to do with the bumpers. I have made the little versions but the car does look great without any bumpers. I wonder about a smaller rubber insert?

 

[Dr.Jeff]

but it is not as bad as you think

Ya, I was just giving you a hard time. But I have seen some amazing automotive fabrication work from your country. Honestly some of the best in the world. I think another factor relating to that (besides the long winter) is you likely are raised with a stronger work ethic than we tend to be. Unfortunately we Americans are spoiled and lazy - myself included.

It's interesting how people in general seem to want what we don't have. For example I've found American car customizers like to build "European" versions of vehicles, while European customizers like to build "American" versions. For example the largest American classic car show in the world is in Sweden, the "power big meet".

 

[carl]

Bobkat, what is it that you find handy about the rear towhooks? I only used them to hoist the car with my engine hoist and then realized I can equally use the shock tubes by sliding them into place, running the large bolt into the frame/tube and hook the hoist chain to the bumper tube. That's why I'm putting a removable cover over the opening.

 

[Bobkat]

Bobkat, what is it that you find handy about the rear towhooks? I only used them to hoist the car with my engine hoist and then realized I can equally use the shock tubes by sliding them into place, running the large bolt into the frame/tube and hook the hoist chain to the bumper tube. That's why I'm putting a removable cover over the opening.

tie-downs for trailering it. If the bumper holes are deleted they there goes that option. Never really thought about it till this thread. Maybe some screw in tow hooks.

 

[Dr.Jeff]

I use the wheels (tires) to anchor the car on a trailer. Loop the tie-down strap around the tire to pull it to the trailer. Anchoring the wheels but no attachments to the body of the car allows it to move on the suspension and smooth out the ride. Kind of like this:

 

[Mechanogeek]

Bobkat, what is it that you find handy about the rear towhooks? I only used them to hoist the car with my engine hoist and then realized I can equally use the shock tubes by sliding them into place, running the large bolt into the frame/tube and hook the hoist chain to the bumper tube. That's why I'm putting a removable cover over the opening.

Some track-day events require tow hooks or straps to be available at both front AND rear. Makes the job of the recovery team much easier (and faster). I am working hard to make mine removeable.

 

[Dr.Jeff]

If I wanted or needed to retain some sort of tow hook, I think I'd do something along these lines. I would create a threaded anchor point off of the remainder of the bumper mount box (as we have been discussing), just behind the surface of the body. Then fill the hole on the body where the bumper mount was, leaving only a small round hole directly over that threaded anchor point. That way I could have a removable tow hook that threads into the anchor point, with only a very small opening in the bodywork.

The hook could be something like this:

The anchor point could be as simple as a internally threaded tube or even a coupling nut, welded to the wall of the box section:

Here is what it would look like when the tow hook is installed. With the hook removed there would only be a small hole:

 

[Dr.Jeff]

After all this discussion about removing the bumper mounts I decided it was time to finish the clean up work on the ones I removed previously. As I said, I wanted to remove the large box section on the inside and not just the rear lip. Looking at it again I have no idea why I decided to do that. It makes no sense to me now. Anyway today I did a bit more cutting, some welding, and grinding to clean up the mess I made when doing it. I strongly recommend that anyone do this the way Carl or Bjorn did.

I also pulled out my rotary (Dremel type) tool and the reinforced cutting wheels to use for some of the trimming work. Honestly Bjorn, I don't know how you did this job with them. You must have much better cutoff wheels for these tools there, because after eating up a couple wheels - and getting very little done - I put it back and returned to using large tools. Like Carl said, these wheels are not cheap either. But I'm sure it can be done and Bjorn's job of it certainly looks fantastic.

 

[Bobkat]

After all this discussion about removing the bumper mounts I decided it was time to finish the clean up work on the ones I removed previously. As I said, I wanted to remove the large box section on the inside and not just the rear lip. Looking at it again I have no idea why I decided to do that. It makes no sense to me now. Anyway today I did a bit more cutting, some welding, and grinding to clean up the mess I made when doing it. I strongly recommend that anyone do this the way Carl or Bjorn did.

I also pulled out my rotary (Dremel type) tool and the reinforced cutting wheels to use for some of the trimming work. Honestly Bjorn, I don't know how you did this job with them. You must have much better cutoff wheels for these tools there, because after eating up a couple wheels - and getting very little done - I put it back and returned to using large tools. Like Carl said, these wheels are not cheap either. But I'm sure it can be done and Bjorn's job of it certainly looks fantastic.

The regular Dremel cut off wheels suck. The Lock cutting wheels cut really fast for Dremels.