Y60 Rear Bumper and corner chop

[Peter Connan]

For the last couple of years, one corner of my car's rear bumper has been pointing out at a rather sad and sorry angle.

Every time I straighten it, the very next trail I hook it again.
Both corners have also been bashed pretty hard from the bottom.

Early in December I decided that the time had come to do something about it.

So I did some drawings.

Basically, my bumper is also intended to be a three-part construction consisting of separate corners and a centre section.
Obviously better protection is the primary goal, as is improving the clearance angles somewhat (if something doesn't bump it can't bend), but keeping the weight down is always important.
I also wanted to make it strong enough to carry a spare wheel on a swing arm, but the swing arm itself will come later.

Complete bumper, from the top:

And from the bottom:

Right-hand corner:

It attaches to the car in a number of places. Firstly it mounts to the same two holes as the metal bracket for the factory corners. This plate is 10mm thick and incorporates a place to mount a recovery shackle.
Secondly it mounts to the ends of the rear chassis cross-member, same as the rubber bumper blocks of the standard bumper.
But it also clamps around the chassis leg at the front end, which should hopefully add a lot of strength.
Lastly, the centre section primarily consists of a piece of thick-walled steam tubing, and this slips into a machined thick-wall socket which is part of each corner, for a length of 125mm.

It also incorporates a hi-lift jacking point at the end closest to the wheel.
This relies heavily on that additional rear mounting point, and time will tell whether it's strong enough to actually jack on.

Expected total weight is around 22-25kg. Not sure what the standard stuff weighs.

[SJC]

Cant wait to see the end product

[Peter Connan]

Of course I got my timing wrong and had to wait until this week to get the parts due to year-end shutdown, but the bumper is tacked together.

Now comes the scary part. Chopping the corners...

[Steele]

Man I wish I had those kinds of skills! Looking good Peter!

[Peter Connan]

Yesterday morning at 06h00 I started dismantling. Renoved the old bumper, the rear wheels, removed the tail lights and removed all the interior bits giving access to the corners.

Then the scary bit: chopping the corners. Never ground on a car's body before.

Tijmen gave me a good idea here. Apply 25mm masking tape with it's top edge where the end of the body needs to be.

But cut along the bottom edge. The make vertical cuts the width if the tape at all the corners. The tabs left behind are then folded inwards. The tape not only guides the cutting but also protects the paint during the bending.

Next step was to fit that corner's bumper, and fix all the design faults. Because I had anticipated some issues, the corners had only been tack-welded.

The process was then repeated on the driver's side. This side is quite a lot more difficult as the shape is more complex and there is wiring below the level of the cut. Check how much mud was in here:

Cutting completed.

[Peter Connan]

The next step was to complete the welding on the bumper pieces, and then prep for paint.

After that all I had time and energy left for was to cut cardboard templates for the filler plates.

This morning I started by painting the bumper corners. But I ran out of paint and had to dash to Builders for some more.

Now there are two ways to close the holes left by the corner chop. The best way is to weld in plates, but I don't have the skill or the equipment to weld tin metal like that, so I used the other method: Sikaflex and rivets. So I decided to use Aluminium as filler plates.

On the driver's side the shape is too complex, so for a portion of the cut I just clamped down on my thumbs and squirted in masses of Sikaflex, then stuck some Duct tape over it to stop the Sika from running out.

At some stage I will have the corners rubberised from the bottom up the the crease in the body which should seal everything up much better than what it was before.

Now just waiting for thr paint t9 dry before attempting to fit the bumper.

[Peter Connan]

And it's done...

[Alex Roux]

Lyk netjies Piet
Nou gaan jy dit kommersialiseer?

[SJC]

Ek hou hiervan, baie nice...

[Peter Connan]

Dankie Alex.

Ek is heeltemal gelukkig om die bumpers te verkoop, maar ek is nie bereid om aan ander ouens se karre te sny nie.

Lank gelede toe ek dit begin oorweeg het, het ek by Oom Jan van Quantum 'n kwotasie vir die corner chop aangevra. Die prys was heel billik, so dis wat ek sou voorstel as iemand belang stel.

Die res van die bumper is net vasbout, geen modifikasies aan die chassis nie.

Dankie Fanus.