Rust and hole on top coil spring perch

[J90rdn]

Started pulling the rear suspension and trailing arms out last night and noticed some right cruddy metal on the drivers side rear upper spring perch.


I'm going to grind back to see where the good metal starts, but I assume I have 3 options;

1. Patch the hole with a made up plate.
2. Buy a new "right side member" from BMW, which includes this part, and find some way of welding it in.
3. Cut out from another car and weld in.

Are these my only options? I'm guessing I could also go coilover at some considerable expense, but I've already shelled out for new bilstein b4 struts all round and new eibach springs.

[Grrrmachine]

Either bash out a repair patch, or cut the appropriate area from a brand new member. Scavenging metal from a wreck is false economy.

It's not a hard repair if you've got a MIG and an angle grinder.

[J90rdn]

Rule out option 2. BMW have just got back to me saying no-one in the UK has one, none in Germany, and no ETA on when they would have one.

[pacerpete]

Local repairs are fine but be sure to have a really good look in that general area . That will not be your only issue.
You also need to remove the spring and top rubber pad and take a wire wheel equipped grinder to the area where the spring perch meets the chassis rail. You will make a hole, I guarantee it . Then check the other side

When you do, we need pics !

[J90rdn]

Local repairs are fine but be sure to have a really good look in that general area . That will not be your only issue.
You also need to remove the spring and top rubber pad and take a wire wheel equipped grinder to the area where the spring perch meets the chassis rail. You will make a hole, I guarantee it . Then check the other side

When you do, we need pics !

You worried me, so I've just been out and removed the springs. Can thankfully report than no further rust under the top rubber on either side. Funnily enough the passanger side is completely rust free top and underneath.

Just ordered some sheet metal so looks like I'll be patching it up. Just out of interest, what is the hole for on the top perch (the one that is plugged with a plastic bung)? Is it just an inspection hole?

[pacerpete]

Local repairs are fine but be sure to have a really good look in that general area . That will not be your only issue.
You also need to remove the spring and top rubber pad and take a wire wheel equipped grinder to the area where the spring perch meets the chassis rail. You will make a hole, I guarantee it . Then check the other side

When you do, we need pics !

You worried me, so I've just been out and removed the springs. Can thankfully report than no further rust under the top rubber on either side. Funnily enough the passanger side is completely rust free top and underneath.

Just ordered some sheet metal so looks like I'll be patching it up


. Just out of interest, what is the hole for on the top perch (the one that is plugged with a plastic bung)? Is it just an inspection hole?

Have you taken a grinder to that area ? Any rust stains / flaking underseal usual turn into a hole when 'investigated'

[J90rdn]

yep, just surface rust. Took the grinder to it after taking this photo



This was the worst side.

[pacerpete]

yep, just surface rust. Took the grinder to it after taking this photo



This was the worst side.

Where the 'plate' joins the chassis rail is where the holes are usually to be found

[jimmyspeed]

get yourself one if these for you grinder -

http://www.toolstation.com/shop/Power%2 ... 920/p21989

they're properly vicious so keep you digits out of the way ! and wear google as they sometime shoot out wire that stick into you, on the plus side they do remove all the paint and loose metal.

[J90rdn]

Just as an update this is how the repair turned out


There was thankfully no rust anywhere else on the spring perch or chassis rail, and the passenger side was rock solid.

Thanks again to all that contributed

[E30cabalan]

Put a bit of waxoyl in the hole for good measure