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Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 10:34 am
by 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.
Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 10:47 am
by 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.
Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 10:48 am
by 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.

Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 10:52 am
by 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 !

Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 12:20 pm
by J90rdn
pacerpete wrote: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?
Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 12:38 pm
by pacerpete
J90rdn wrote:pacerpete wrote: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'

Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 12:44 pm
by J90rdn
yep, just surface rust. Took the grinder to it after taking this photo
This was the worst side.
Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 1:02 pm
by pacerpete
J90rdn wrote: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

Re: Rust and hole on top coil spring perch
Posted: Wed Jan 15, 2014 1:42 pm
by 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.
Re: Rust and hole on top coil spring perch
Posted: Tue Mar 04, 2014 12:05 am
by 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

Re: Rust and hole on top coil spring perch
Posted: Tue Mar 04, 2014 12:47 am
by E30cabalan
Put a bit of waxoyl in the hole for good measure
