Repairing rear axle beam mounts
The rear axle beam mounts are a notorious rust trap on Scirocco Mk1 and Mk2 and can lead to MOT failures and owners deciding to scrap their cars.
Repair panels are available from after market suppliers such as Hadrians and Crazy Quiffs in the UK. These panels are mainly listed under Mk1 Golf, as the chassis is the same on both Mk1 Golfs and Sciroccos.
There are various methods and approches to repair, this is the one that worked for me on a Mk1 Scirocco. I was repairing the os (UK drivers side) mount.
Before tackling the repair, you will need to jack the car up and rest it on axle stands. Best place the axle stands beneath the two potruding brackets just ahead of the rear valance as you will require plenty of access. Remove the rear road wheels, disconnect the rear brake flexy lines, remove the rear suspension struts and undo the rear axle beam by undoing the four nuts that hold it in place. Be careful not to snap any of the studs (if you do, I will be tackling this below, more to come…). Once the rear axle beam is free you will need to remove the fuel filler neck, the fuel tank and any pumps, flexy lines etc. If fuel lines are left in situ, make sure that they are not left exposed -as you will need to cutting and welding in this area. SAFETY FIRST!
You can then finally get to fixing your rear beam mounts.
os mount rusty -stud snapped!
(click image to see larger pic).
I did this repair whilst the car was on a chassis tilter, so some of the pic angles may seem a little odd. But it is perfectly possible to condust this repair from under the car, its just a bit more uncomfortable!
The beam mount above is pretty rusty, that is what it looked like after attacking for a bit with a wire cup on a grinder, so i could see what i was looking at.
Start by cutting away the rusty metal. I used an angle grinder, hammer and chisel and mole grips.
os mount cutting away
removing metal
You will end up with something like this:
os mount
As you can see, the mount is two ‘bolts’ fixed into a thick ‘U’ shaped bracket. This piece is generally just pitted with surface rust, only in isolated cases does this piece fail, its usually the metal around it that collapses! If ths piece is terminal, it is is possible to replicate the mount and repair, but this is beyond the scope of this article, as the mount itself here is sound with a bit of surface rust and attached where it should be. We are looking at replacing the external axle mount cover here.
Begin cleaning up the mount and surface rust using a grinder with wire wheel and 80 grit sanding wheel attachments. You will also need to remove some of the underseal and take the paint back to metal to give a clean base to weld to.
removing surface rust
Once you are happy with the removal of the surface rust and the remedial care given to the surrounding metal, give the parts that will later be inaccessible a coat of rust killer to try and ensure that the nasty stuff doesn’t come creeping back.
rust killer applied
At this point I also drilled the snapped stud out following the instructons given in the Haynes manual. The hole will be tapped for a bolt. The outer sill cover rail was also drilled to plug weld the sill to the rear of the repair panel.
This is the repair panel as purchased:
rear mount repair panel
The panel is measured and cut down to fit the repair required. At this stage you can never do enough trial fitting and measuring. Use the axle nuts to help you align the panel where you want it.
aligning os mount
The panel required cutting flaps at the top to allow it to be shaped to fit the countour where it will be welded in place. Tin snips and a hammer are your friends here! I also drilled some holes to plug weld it into place to help the strength both at the edges and where the repair panel meets the mount itself. The edges of the panel were taken back to metal ready for welding.
repair panel prepared
The repair piece is clamped up, tacked to hold in place, then fully welded into place.
repair panel welded
The welds can then be dressed as much as possible to end up with a clean repair (hopefully!)
dressing welds
The repair is completed and primed to protect the welds from surface rust.
in primer
Seam sealer and stone chip to follow.
hi.. i see the rear awle mounting bolt has sheered off – what is the best method of repair for this??
Thanks for comment and Q -it will be repaired following the guide in Haynes, which is quite specific. the old stud was drilled out and has been tapped for a bolt. I will add this to the article one done.