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Reserve fuel tank - Spare Wheel

Posted: Mon Apr 13, 2015 12:43 pm
by Ubercoupe
Inserted my (new to me) Reserve fuel tank into my spare wheel, and the treaded bolt is just shy of the metal disk, I can't get the wing bolt attached to secure the Reserve fuel tank/ Tyre. Any help appreciated! The OEM Alloy is late highline 195 TR 415 CH.

Posted: Mon Apr 13, 2015 6:11 pm
by JCS
Try the tank in first, then the tire.

Posted: Mon Apr 13, 2015 9:55 pm
by Ubercoupe
Thanks for the reply, I think it's the metal disk, RealOEM references three different types. I know these tanks are rare outside Germany. maybe someone will chime in who has one.

Posted: Mon Apr 13, 2015 10:13 pm
by JCS
I mean put the tank into the spare tire well, and put the tire on top, facing finish side up.

Posted: Tue Apr 14, 2015 2:14 am
by sansouci
Could the spare tank fit OVER (rather than under) the spare tire hold down?
Or is the hold down bolt longer with the spare tank? Did the spare tank come with the car and the hold down or did you add it?

Posted: Tue Apr 14, 2015 9:43 pm
by Ubercoupe
The spare wheel tank is a retro fit. They were compulsory in Germany. An OEM part branded BMW. not available now. Mercedes had similar, Internet pictures seem to display the tank sitting in the wheel well face up.

Posted: Tue Jun 30, 2015 11:18 am
by Ubercoupe
That worked, cheers for the reply

Re: Reserve fuel tank - Spare Wheel

Posted: Thu Feb 09, 2017 2:35 pm
by guido

Re: Reserve fuel tank - Spare Wheel

Posted: Sun Apr 23, 2017 2:57 am
by DRPM635CSi
The spare wheel must go in upside down when you have one of these. The instructions even state so. If you fit the fuel tank first and then put the spare wheel over it, the retaining washer/bolt will only hold down the spare wheel from moving around, not the fuel can underneath, so you'd be hearing the canister going clunk-clunk-clunk and getting all scratched up as it smacks around against the inside of the wheel rim as you brake and corner.

https://www.dropbox.com/s/5oumb44kptquq ... .pdf?raw=1

The reason your retaining washer doesn't allow the threaded bolt to protrude through far enough to get the wing nut on is because a special washer is needed in conjunction with the fuel canister. It's part number 82-11-9-413-201 and is long since NLA. I have one but have been unable to find anyone who can reproduce it economically. It's a special profile shape with a deep recess for the wing nut to reach the threaded rod of the hold down bolt. It also has an unusually small Ø80mm OD to perfectly match the centre-bore of the fuel canister and sits perfectly flat & flush. It is also completely circular without a slot interuption like some of the wheel hold down plates.

Probably your best option to find a retaining washer that looks genuine is to scour some wreckers and see if you can find a plate from other model cars with a deep enough centre recess to expose the thread for the wingnut if it were turned down to Ø80mm on a lathe and then get that done.

On this subject... does anyone know the part numbers for the twin retainer washer plates for the spare wheel hold down assembly employed in the M635CSi? The twin plates that sandwiched the flimsy little piece of driftwood chipboard used to maintain a flat boot floor above the spare wheel in the M635CSi exclusively? The top one of these plates could be turned down to Ø80mm OD to produce a workable OE looking retaining washer for the auxiliary fuel canister in place of the unobtainable 82-11-9-413-201.

Re: Reserve fuel tank - Spare Wheel

Posted: Wed Apr 26, 2017 5:45 pm
by Ubercoupe
thanks DRPM635CSi, great research work, thanks for the PDF.

Re: Reserve fuel tank - Spare Wheel

Posted: Fri Apr 28, 2017 11:05 pm
by Steve Corbett
Thanks DRPM635CSi, I've been looking for that info. Can you post a few pictures of the hardware and washers used?

Re: Reserve fuel tank - Spare Wheel

Posted: Sun Apr 30, 2017 5:47 am
by DRPM635CSi
As requested:

82-11-9-413-201
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The M635CSi washers I want to know the part numbers for:
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