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rear subframe mounts

PostPosted: Tue May 30, 2017 1:31 pm
by Jin
Need to replace the rear LH subframe bracket, how much of a pain is it to do? I’m thinking access etc., do i need a double jointed midget to assist or is it straight forward?

This is a mk4 but im hoping 3s will be similar?

Cheers

Re: rear subframe mounts

PostPosted: Tue May 30, 2017 8:11 pm
by ACourtney
It depends on who built the car and whether it went through an SVA test. I have a hunch that yours was an early Cortez and may predate the SVA?

The SVA testers are not happy with the original system of three bolts with penny washers and ask for a fish plate to spread the load better. As they used to say on Blue Peter "here's one I made earlier"

ImageIMAG0151 by Alistair Courtney, on Flickr

Sensible builders will have welded the bolts to the fish plate (My Excelsior was built by the Redditch outfit who didn't weld them). With the bolts welded to the plate you only need to lean through the speaker hole once to push it into place. If you are unlucky then you will be having to buy a drink, or two, for your double jointed midget.

Re: rear subframe mounts

PostPosted: Tue May 30, 2017 11:07 pm
by Jin
Cracking idea grommet
Don't know why I didn't think of it myself.

Looking at mine I doubt it's the same as from outside I can see bolt heads and not the nuts.
I'll make a pair of them brackets up and maybe just drill the heads off the old bolts to save bringing the midget into service (pesky midgets always wanting drinks anyway )

Cheers mate

Re: rear subframe mounts

PostPosted: Wed May 31, 2017 1:28 pm
by Jin
Can you give me an idea on bolt length?
Cheers

Re: rear subframe mounts

PostPosted: Thu Jun 01, 2017 4:51 pm
by ACourtney
40mm should be adequate, but it is worth checking first as the GRP thickness varies a lot, especially with GTM moulded cars.

Re: rear subframe mounts

PostPosted: Thu Jun 01, 2017 11:43 pm
by Jin
Ahh haa
So I went ahead and blindly made the brackets (45mm bolts so not far off )

Image

And began stripping out the old brackets.

Penny washers not good enough?
Lol these aren't even nylocs never mind washers. ....

Looks like I've some work to do. The lower bolt wasn't even tight presumably because it's drilled too close to the Base of the sill or the laminate is too thick there, had similar issues with the front subframe. So not too sure about the way forward here , it dosent look right but has potentially lasted 22 years like this?

Image

Re: rear subframe mounts

PostPosted: Fri Jun 02, 2017 1:05 pm
by fozzza
Im quite interested in this topic as I am working on the rear end of my MK3 at the moment and wondered if it was now imperative to use fish plates instead of penny washers or is the SVA tester suffering a little OCD, but now I have seen how someone has bolted Justin's subframe on Im some what speechless. :o

Re: rear subframe mounts

PostPosted: Fri Jun 02, 2017 2:05 pm
by Jin
There's no way I'd personally use anything less than heavy duty penny washers however theres no denying thst the car has lasted well with nut 2 plain nuts and nothing else lol

Re: rear subframe mounts

PostPosted: Fri Jun 02, 2017 3:52 pm
by ACourtney
The GRP is pretty thick there so penny washers would probably be okay, but having the bolts welded to the fish plates makes fitting the subframe mounts a lot easier.
Judging from the photo, the GRP is not only thick, but rather uneven. I suspect Justin is going to have to trim back the edges of the fish plate to get it to fit. I think that I would take the old nuts off and then make a paper template of the area inside the sill (looks like you may have to by the double jointed dwarf a drink after all).

Re: rear subframe mounts

PostPosted: Fri Jun 02, 2017 5:56 pm
by Jin
Ha ha.
Yes the plate I made up and neatly painted will have to be cut down considerably, however I think it's a must as the lower hole is right on the Base of the sill meaning I'll have to cut into the bolt head to get it to fit in sill so I'll need as much steel in the rest of the plate as possible.
I'll see how I get on tonight.