Hi all.

Bought a new battery tray which was pre drilled to fit the existing BUT my existing holes look like they have blanking plates over them. Do the press out or are they screwed in? Or are they even BMW fitment at all and somebody has added them?

Pete

I am thinking that the"blanking plates" are broken rubber vibration mounts.  They should unscrew from the transmission.

Ah okay. Thats good news. Didn’t want to start destroying things trying to remove them and then have to make them look good again

Thanks for the reply

Hmm, no. Seems that they are metal. 

Point-Seven-five wrote:I am thinking that the"blanking plates" are broken rubber vibration mounts.  They should unscrew from the transmission.

Are you looking at four metal discs about 2cm in diameter?  If yes, what you see are the metal parts of the vibration dampers after the rubber bit comes off.

This is what the "new improved" version looks like:





It's not uncommon for them to be broken from the weight of the battery and the forces on it pulling against them.  Corrosion also leads to them breaking. 

If you want to remove them, it will probably take a lot of penetrating oil and heat.  Then grab them with vise grips and unscrew them from the top of the transmission.

That makes sense now I’ve looked again. I thought that someone may have siliconed them in place but that’s obviously the remains of the rubber mount. Thanks for your responses, I’ll bet busy with the wd40 and the blowtorch

Point-Seven-five wrote:Are you looking at four metal discs about 2cm in diameter?  If yes, what you see are the metal parts of the vibration dampers after the rubber bit comes off.

This is what the "new improved" version looks like:





It's not uncommon for them to be broken from the weight of the battery and the forces on it pulling against them.  Corrosion also leads to them breaking. 

If you want to remove them, it will probably take a lot of penetrating oil and heat.  Then grab them with vise grips and unscrew them from the top of the transmission.

As noted, Vise-Grips are good for removing them. However that plate is very thin so it helps if you push down on the Vise-Grips to make sure they're flush with the transmission.  Use the side of the Vise-Grips to get the teeth to bite into sides of the lip.

When installing replacements use anti-seize and don't uber tighten them.

With a little care you can TACK WELD a nut to the plate then use a socket to remove .This way gets heat well into the stud and is far better than a blowtorch

Another way to get it out would be to use a center punch radially near the perimeter of the little round disc. Once you get it started turning a bit then you can just be able to unscrew it by hand.

WD40 is not a real penetrating oil.  You would be better off getting a real penetrating oil or better yet making your own. 

There are tests that show the best lubricant for loosening corroded fasteners is a 50/50 mix of acetone and Automatic transmission fluid.  If you don't want to buy a whole liter of acetone, get a bottle of nail polish remover and use that.  The bonus is that many of them come with a small brush that you can use to apply the mix to the rusted part.

Don't worry about having nearly all of a liter of ATF hanging around.  What you don't use for penetrating oil makes an excellent fork oil.  It's the right viscosity, has viscosity stabilizers, corrosion inhibitors, and seal preservative, too.  I don't know about their current bikes, but I know Honda used to specify it for the forks and rebuildable shocks on their competition bikes bikes back in the 70's and 80's when I was riding them.

Point-Seven-five wrote:There are tests that show the best lubricant for loosening corroded fasteners is a 50/50 mix of acetone and Automatic transmission fluid.

Nope. It's a 50/50 mixture of carbontetrachloride and ATF. The guy that originated that test is really hacked off with seeing 'acetone' written down. ATF dissolves in CTC but not in acetone. I had the link to his results once but... It also turned out to be only marginally better than the commercially available Kroil which is... expensive. Very expensive in the UK. I paid £23 for 250ml and that was cheap compared to most prices I was seeing.

Also, another way to get buggered anti-vibration mounts out: https://www.k100-forum.com/t15894-bike-to-good-home - post 18. You'll need to click on the image links.

https://www.youtube.com/watch?v=xUEob2oAKVs

Personally, I have been using Liquid Wrench for over 50 years, ever since I worked in a gas station at the tender age of 19.  One of my tool boxes still has the now empty can I bought back in 1970. 

BTW, in this test the mixture he used was acetone/ATF. 

And the real winner is...

...HEAT!

I've started a 1983 K100 resto. The ECU vibration dampers are similar to the battery tray dampers. The ECU threaded steel posts at each end of the rubber damper are M6 thread. Mine were stubbornly stuck. Because of the rubber damper I did not to apply heat from a gas torch for fear of weakening or destroying the rubber. My application of liquid penetrating fluid did not do the job. Eventually I removed the dampers by inserting 2 flat blade screwdrivers at 180 degrees to one another and gently driving their blades in under the bottom metal washer and levering with gradual increasing force. The rocking motion led to success and the shallow thread in the frame mounts are still able to be used. If the female threads in the frame mounts were damaged I could have fitted a clip type panel nut. 
One earlier forum post suggests cutting parallel sections out of the two metal end washers on the damper to allow you to use a spanner or pliers and exert enough torque to break free the seized threads. does this method not risk destroying the rubber part of the damper?
I'm replacing the vibration dampers anyway because of their 39 year old age. BMW originals are expensive. I've purchased on eBay some machinery vibration dampers with M6 threaded metal posts for a good price. I selected 10mm thickness for the dampers which allows me to fit rubber washers as shims to match the original thickness of the dampers. I'm going to apply anti-seize paste to the threads when refitting - ancient machines with threads of different metals invite corrosion and stuck fasteners.

redrockmania wrote:One earlier forum post suggests cutting parallel sections out of the two metal end washers on the damper to allow you to use a spanner or pliers and exert enough torque to break free the seized threads. does this method not risk destroying the rubber part of the damper?

As per the OP (post 6), there's no rubber left, just the bottom plate. You also don't need to be quite so accurate with the aftermarket anti-vibration washers as, IMNSHO , it depends more on the battery height. I've fitted 15mm x 20mm replacements and I use a Motobatt AGM but I did have to mod the securing bar over the top to hold the overflow tank because the Motobatt is taller than the OEM battery. Additionally, because the battery tray threads on LFB were pretty close to being toast, I tapped to 8mm and made new securing posts.

(Yes, I'm laughing at myself)