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JFW Tue Jul 07, 2020 4:19 am

Hi guys,

I'm continuing the work on our '89 Caravelle Syncro (JX, PS, 2xdifflocs). There's quite severe rust in the cross beam that runs above the transaxle + in the firewall down towards the floor panel. Before I start choppin' it would be extremely valuable if any of you have advice/procedures or pictures (or threads) that cover this spesific repair.







Thx!

Truls Erik Johnsen
Norway
www.johnsenframeworks.com

MarkWard Tue Jul 07, 2020 8:32 am

Sorry, can't point you anywhere. I converted a 2wd to syncro last year and had to fabricate a syncro tank mounting. Swapping the factory mount from the donor was not practical and you can see what a mess it makes. This was somebody else's idea and I copied it.



It is backed up on the inside with 1/8" flat plates. I used the original mount to locate it and the weld nuts you can't see for the tank strap. I chose to bolt it vs welding it to keep as much as the stock paint intact. I thought this might give you an idea about how to deal with remounting your tank.

JFW Tue Jul 07, 2020 11:03 am

Thanks Mark. I might go for the replacement tank bracket made by TH-Parts. In regards to the firewall I'm going for a full dissection now. Starting with drilling out the weld spots in the floor, then cut a part of that out to access and repair the cross beam from the top + repair the firewall before practice putting it all back in the right order.




Cheers,

Truls

T3 Pilot Tue Jul 07, 2020 11:09 am

http://wiki.club8090.co.uk/index.php/Areas_that_rust_-_Rear_cross-member

JFW Tue Jul 07, 2020 1:21 pm

T3 Pilot wrote: http://wiki.club8090.co.uk/index.php/Areas_that_rust_-_Rear_cross-member

Thanks a lot, Mr. Pilot. That is a really good description. I thought I had searched through the Club 8090 pages properly, bi I had apparently missed this one.

Cheers,

Truls

djkeev Tue Jul 07, 2020 6:03 pm

Who knew?!?

First I've heard of Syncro fuel tank area rust.
Always Something new to learn.

Dave

JFW Wed Jul 08, 2020 12:42 am

djkeev wrote: Who knew?!?

First I've heard of Syncro fuel tank area rust.
Always Something new to learn.


Haha. Well, I don't think that rust in the Syncro's (plastic) tank have been mentioned anywhere in the thread. However, given all the weirdness going on in the world right now you never know!

For future reference: This one also covers repairs in the same area well: https://www.vwt3.at/index.php?/topic/50022-sanierung-motorraum-incl-blecharbeiten/

Truls

JFW Wed Jul 08, 2020 7:46 am

So, I decided to move on with the floor-removal process. All spot welds where drilled out and then the floor was cut out with an angle grinder with a 1mm disc. Super easy, really




Not surprisingly the cross-beam where filled with old crud and rust, and after a proper vacuming it's easier to plan the next steps to repair it. The plan was to do most of the work on that from the outside (under the car) but after opening up it's evident that the bottom U-shaped piece also needs to be repaired due to severe rust damage. I'm still trying to figure out how to do it properly while keeping all the bolt mounts
+ brackets aligned and in the same spot as original.

More to follow!

Truls

MarkWard Wed Jul 08, 2020 8:07 am

When I did my conversion, I had to add those securing nuts. I was able to make nut plates and slip them into position through one of the factory cutouts.

From memory, its a pretty stout part already. You might be better off, dealing with the rust and adding some stout 3/16 th custom nut plates in place of the original nuts. This will help to maintain the original position and probably out last the van. Use the brackets to maintain the position doing one nut at a time.

You have the access I didn't have. I secured my plates from below and then rosette weld them into position.

JFW Thu Jul 09, 2020 12:56 am

The plan now is to make a replacement piece much similar to the one TH-Busparts had available earlier (he's working on an improved version now). So it'll be a process to transfer the securing nut positions to the new piece + the location of the brackets. Should'nt be too much of a problem, really.






Br,

Truls

MarkWard Thu Jul 09, 2020 6:45 am

Looking at your pictures, there looks to be a lot more good metal. Its at least double wall and possibly 3 wall in a couple spots. I think you could reinforce really well from inside after you treat the rust and maintain the subframe brackets and trans mount locations.

If you cut the entire section out to replace with a part similar to above, you are triple complicating the job in my opinion. I spent hours trying to locate the subframe ears and the transmount holes. It required installing and removing the engine trans and sub bars mulitple times. It has to be correct.

Do you have access to a media blaster?

T3 Pilot Thu Jul 09, 2020 7:04 am

Looks like you are effecting a thorough repair job.

Those images of the interior of the cross member make me want to blast and vacuum and then flood the interior with wax/oil on my Vans.

JFW Thu Jul 09, 2020 7:17 am

MarkWard wrote: Looking at your pictures, there looks to be a lot more good metal. Its at least double wall and possibly 3 wall in a couple spots. I think you could reinforce really well from inside after you treat the rust and maintain the subframe brackets and trans mount locations.

If you cut the entire section out to replace with a part similar to above, you are triple complicating the job in my opinion. I spent hours trying to locate the subframe ears and the transmount holes. It required installing and removing the engine trans and sub bars mulitple times. It has to be correct.

Do you have access to a media blaster?

Thanks, Mark. Yeah, I have access to a media blaster. The challenge here is that there is severe bulging between the layers when seen from below as well, and as you can see from my pictures there's litterally a few millimeters of rust between the layers seen from the top. In additon the outer rear wall of the beam is rusted through in several spots. I could perhaps rebuild the whole piece as it was original, but that makes no sense since it would be both overly complicated as well as it would reintroduce the original problem where water is captured between the layers. Cutting out the original piece with a thin disc and then measuring and transfering the subframe ears and mounting holes should'nt really be that hard when the piece is out of the van. I have a fullsize surface plate + precision measuring equipment in the shop. All of that detailed work can be done inside with full control, and then it's just to MIG it all in place again when it's ready. Hopefully the profile is ready tomorrow. More to follow!

Truls

JFW Thu Jul 09, 2020 7:19 am

T3 Pilot wrote: Looks like you are effecting a thorough repair job.

Those images of the interior of the cross member make me want to blast and vacuum and then flood the interior with wax/oil on my Vans.

Haha. Yeah, I think this area is most likely hidden and forgotten by most van-owners. I would'nt have captured it either if I did'nt remove the transaxle and tank to change the tank straps.

Br,

Truls

MarkWard Thu Jul 09, 2020 8:07 am

Then I would tack up a couple tabs from the chassis that locate the mounting holes before you cut the piece out. This will give you a way to reposition it correctly. Lower brace tabs can be added later with the trans and engine installed.

JFW Thu Jul 09, 2020 8:53 am

MarkWard wrote: Then I would tack up a couple tabs from the chassis that locate the mounting holes before you cut the piece out. This will give you a way to reposition it correctly. Lower brace tabs can be added later with the trans and engine installed.

Good idea. I'll make some temporary jigs to make sure that it goes in at the exact same spot as it where originally.

Truls

howardvw Thu Jul 09, 2020 10:26 am





after welding in a new wall, i made the tank mounts out of L shaped stock metal, maybe 10 gauge, i cut a slit in the wall then welded on the inside the flat against the wall so when it pulls down its pulling the wall. i cut a hole in the bracket and welded a bolt for strap hookup.

JFW Fri Jul 10, 2020 2:43 am

howardvw wrote:

after welding in a new wall, i made the tank mounts out of L shaped stock metal, maybe 10 gauge, i cut a slit in the wall then welded on the inside the flat against the wall so when it pulls down its pulling the wall. i cut a hole in the bracket and welded a bolt for strap hookup.

Thanks Howard! Was this done just to avoid making a replacement piece like the original bracket?

Truls

JFW Fri Jul 10, 2020 2:52 am

Just a quick one with the dimensions for the replacement piece:

Truls

howardvw Fri Jul 10, 2020 5:09 am

yes, and i only had a non syncro body to cut donor metal from. from what i can remember, 10 yrs ago, i was looking at the original bracket and thought the wide size of it is more for the actual positioning of the tank than for hanging of the tank, so i went with a small bracket. heres a pic of the inside i took today-



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