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Large MPVs -- Ford Galaxy / VW Sharan / SEAT Alhambra: => Ford Galaxy / VW Sharan / SEAT Alhambra => Topic started by: Orbis on June 28, 2018, 10:11:16 PM

Title: Rust problems underneath
Post by: Orbis on June 28, 2018, 10:11:16 PM

My MK1 is nearly 20 years old en that age is bringing some problems with it :) Got to replace the clutch for the first time as the damper springs are worn and squeaking as I push the car back and fort (in gear). But first of all I have a rust problem uderneath:


As you can see there are some rusty holes  >:(
However I do have the new part from VW:


This is spot welded into place but I would'nt have acces tot the areas in green circle if I would replace the whole part. I would first have to drill the spot welds loose. But that's a lot of work but maybe it's better to leave it and cut out the bad part and make a new part to weld into place? What are your ideas? I don't think that patching another plate over the rust would be a good long lasting fix...

Comments are very welcome and thanks in advance :)
Title: Re: Rust problems underneath
Post by: johnnyroper on June 28, 2018, 10:59:49 PM
I would just cut out the bad bits and make a patch from your new section to weld in if it was me.
Title: Re: Rust problems underneath
Post by: sparky Paul on June 29, 2018, 12:48:24 AM
When mine went, that's all I did - cut out the bad bit above the T-shaped double skinned bit and fabricated a replacement piece to fit.

There'll not be much left above the T plate, and even that may be cheesy. Also bear in mind that the replacement pressing will not be double skinned, as the lower strengthener plate is a separate part.
Title: Re: Rust problems underneath
Post by: brianh on June 29, 2018, 04:56:15 PM
My mk1 had the same failure (though worse than yours, I'd guess ours disolve into rust here quicker than whereever you are) and that was plated over the top, That was fine a year later, The engine failed before it became a problem again on that.

Had the same on the mk2 on the last mot its had, again simple plate over the top was enough for the mot, probabbly worth flushing out all you can from there now if your plating it, welding it up and using some sealer on it. Best thing if you want to keep it longer is to flush out the area with the hosepipe after its been used in poor conditions (salt on the roads etc)
Title: Re: Rust problems underneath
Post by: brianh on June 29, 2018, 04:57:42 PM
Alternatively if you wanted to use your part, if you can bend those two problem flaps to be outside of the box section you could then weld them onto the outer rail as you'd be able to get to them then.
Title: Re: Rust problems underneath
Post by: sparky Paul on June 29, 2018, 06:55:55 PM
It seems a shame to start chopping up such a nice pressing, just to replace something that can be made out of an offcut of 14 gauge and a few bends - and that will be thicker than the original.

Brian is right about keeping it clean, it's a muck trap, and is perfectly placed behind the front wheels. After welding up, body shutz kept mine solid in that area until its retirement.
Title: Re: Rust problems underneath
Post by: daddyfixit on June 29, 2018, 08:39:16 PM
my mk2 also went on the offside one....made up a plate that attached to side of chassis leg..  (did not know repair panels are available either ?)
Title: Re: Rust problems underneath
Post by: Orbis on June 30, 2018, 03:03:11 PM
Thanks for all those replies :) I think I will go with cutting out the bad part an bend some new metal to weld in. Then I still got the new part if it goes wrong :p And yes the parts were available by VW (but not Ford anymore). The part numbers are 7M3 802 203 for left and 7M3 802 204 for right. Replacing the whole part would be the best solution but really not an easy task. I hope to start with it in two weeks and I will post some photos of the repair.

Any idea of which steel I best use? maybe I should visit a car bodyshop and ask there for a piece...
Title: Re: Rust problems underneath
Post by: sparky Paul on July 01, 2018, 11:30:05 PM
I would go for something at least as thick as the original pressing you have, and preferably the next size up - in metric that's probably 1.6mm or 2.0mm - or 16 & 14 gauge in imperial.

Here in the UK, I would go to my local engineering stockholder - as well as all sorts of other metal products, they sell sheet steel, or parts of, and often have an off-cut bin full of pieces trimmed from cut sheets. You can usually grab a few useful bits and pieces for a little beer money.
Title: Re: Rust problems underneath
Post by: Orbis on July 11, 2018, 10:33:31 PM
small update: the part is really too rusty to just weld a patch. So I have no choice and I'm going to change the whole part. I have it so I better use it rather then putting it on a shelve for storage :p I removed the stone ship today to have acces tot the spot welds. Now I'm going to buy a spot weld drill to remove the old part.

I will keep you all updated  ;)
Title: Re: Rust problems underneath
Post by: brianh on July 12, 2018, 12:02:06 AM
You have no idea just how badly things rot over here if you think thats bad. I've had a sill rot in the course of a year from being solid one year, to having a hole big enough to fit your fist inside by the next mot. But still you have the bit so you might as well use it.
Title: Re: Rust problems underneath
Post by: Orbis on October 24, 2018, 07:21:47 PM
It's been a few months now but I've been busy every free moment I had. By looking how many rust there was I became a bit disencouraged. So I started with a lot of other things like maintaining the wiper linkage, fixing a bad engine ground, cleaning the engine bay, deal with every other rust spots I could find. I also replaced the clutch. Why? the clutch disc was actually barely worn but there was a lot of play in the center and the clutch disc springs were worn, loose and rattling. So Im looking forward to drive it again with the play in the drivetrain gone :)

back on topic:

The last few weeks I finally started repairing the bodywork. I had to cut out and weld in three other sections of panels as well.



For the outer part I bought a Van Wezel aftermarket sill to cut out the part I need. Before Welding this I first need to weld in the part I bought from VW. I also closed the big hole by welding in a round plate. Don't know why it is there but it has no function as I see it.


For the oval hole I bought some nice plugs from VW that fit perfectly. Water ingress is now history (or it should be) but there is also a danger that water (that did find a way inside) cannot escape anymore. So in the first place I will make sure that the structure is totally closed but I will check frequently for moisture inside. The part number for the plug is 1K0 899 184. The inside wil also get a 'hollow section wax' treatment.


Feel free to post your comments or remarks :)

Title: Re: Rust problems underneath
Post by: brianh on October 24, 2018, 11:02:18 PM
I'd guess the hole is there to allow them to squirt underseal inside the part. It doesn't really work as a drain hole as its halfway up, so allows all the mud and such to get in there, where it can't easily get back out from. Either that or they were originally filled by something that has long since fallen out of the hole.

Looks like a thorough job your doing there though.