I checked with various BMW garages and part stores but nobody knew what it was. It wasn’t shown in any of the part drawings.
BHPian Jeroen recently shared this with other enthusiasts:
Time for an update on the Mini. The Mini had developed a small problem with its window spray. It would not! So time to check and see what is going on. The obvious first cause of action is to check the fuses. But the fuse was fine.
So time to pull the little pump out and see what is happening. I put the Mini in my garage, jacked it up and put two jack stands underneath it.
The pump and the reservoir are accessible via the left wheel well, so the liner had to come out. Well, I just peeled it back a bit.
I pried the water reservoir pump off.
Put my multimeter on the wires. The Mini has two nozzles at the front window and one at the rear window. These pumps are pretty simple, they can turn in both directions, and the turning direction determines which window gets sprayed.
I got 12 VDC and it also changed polarity when switching between front and rear window spray. So it all looked good. Cleaned the contacts and put everything back on and everything worked again. So whether the contacts were dirty, the little pump got stuck a bit or a combination, we will never know. It’s working again and that is the important thing.
If you have followed this thread you will recall I wanted to change the transmission oil on the Mini. Only to find I could not get the filler-bolt out. It had been damaged badly by somebody in the past. I tried twice with the Mini on the lift at my friend Bernd’s garage.
Here you see it, notice the image is 90 degrees tilted.
As I had the Mini in my garage and up on the jack/stands I decided it was time to have another go. I bought several sets of different bolt extractors.
The filler bolt is an Allen bolt and the inside was stripped. I decided to drill a slightly larger hole into it and then use one of my new bolt extractors. The challenge on these Mini’s is accessibility. It is very difficult to get to anything and to this bolt in particular. No way any drill would be able to get in there. But I have my right-angle pneumatic drill. The good news, it runs at very high RPM, the bad news, it runs at very little torque. In the end, I had to use about 6 drill bits, each 0,2mm larger than the previous one to get a proper hole.
Rammed in my new extractor and voila!!!
Very happy with that. I bought two new bolts, one for the filler, and one for the drain plug.
Look at that:
As I had the filler bolt out, I could now safely remove the drain plug. Not much fluid came out, which was concerning! But I plugged it up and started to fill the transmission box with fresh transmission fluid
I used my special transmission fluid pump canister thingy
After I had pumped about a litre of transmission fluid into the box, all of a sudden I had fluid running past the shaft seal!! So the Mini had a busted shaft seal.
Which might be the explanation for there being so little fluid left!
So I ordered a new shaft seal and it arrived the next day.
Next, I had to remove the complete right-hand drive shaft. Which means taking a couple of things apart, starting with the right suspension. Undid two nuts and you can move the complete brake and suspension assembly sufficiently to also pull the shaft out of the box.
But before being able to pull the shaft out I also had to remove one of the engine mounts.
Used a simple block of wood wedges so the engine more or less stays in position with the engine mount loose.
Next, the intermediate shaft bearing mount has to be unbolted.
Now I could just push/pull on the right brake set/suspension and the shaft popped out of the gearbox!
So far so good! I had only been at it for about one hour and everything had come apart easily, so I was optimistic.
Managed to extract the old seal. It looks pretty much damaged, but that is due to the extraction. It is impossible to extract these seals without damaging them. No issue as I was going to replace it anyway.
Old and new seal, checking for size and dimension.
You might have noticed that large plastic ring around the shaft. let me show that image again:
Initially, I thought it was some sort of cover for the seal. I checked with various BMW garages and part stores but nobody knew what it was. It wasn’t shown in any of the part drawings. Eventually, I found a BMW mechanic who told me it was the remains of the shaft insertion tool. BMW used to supply these tools with the new seat. It allows for easy insertion of the shaft through the new seal and is supposed to avoid damaging the rubber inside the seal. He told me they never used it as it was easy to install the shaft. But when you do, you are supposed to cut away the remaining bits, which the previous mechanic must have forgotten.
Installing the new shaft seal required a special BMW insertion tool. Which I don’t have, so I made one on my lathe!
You will have seen me use all kinds of different aids to install these seals. Often a socket will do and I have used other ring-shaped bits from my tool collection. But the Mini shaft seal was larger than anything I have in my shop. The trick of installing these seals is to be able to hammer them in straight. That only works if you have something that covers the entire circumference of the outer ring of the seal.
I did have to remove another bracket as I could not swing my hammer enough.
One new seal was installed!
So far, including making my seal insertion tool I had been working on the Mini for less than three hours. Things were going well. Right up to this point!
I thought it would be easy to re-insert the shaft and bolt everything down again. Whatever I did and tried I could not get that shaft back in!! I struggled for several hours, lying on my back working that heavy shaft above me.
Time to call spanner mate Peter, to give a hand. I thought it might be due to the fact that on my own I could just not manoeuvre the shaft properly. Plenty of guys on YouTube can however.
Anyway, Peter came and we decided, just for good measure, to remove the complete front drive shaft. Till now, it had still been attached to the wheel hub. Which also makes it more difficult to move it around.
So we removed the locking nut on the drive shaft. This is always tricky because, in theory, the shaft should come out easily. In practice, it usually takes a bit of violence, if not outright force.
Mine came out after a couple of good whacks with a heavy hammer.
We tried for hours to get this shaft back in. In the end, I had to tow the Mini to a nearby friendly workshop. With the car on the lift, the shaft finally popped back in. But when we started filling up the gearbox with fresh transmission fluid it leaked again.
Time to consult the real Mini Specialist. I called the guys at Ben van Leeuwen.
Ben has been working his whole life on Mini’s. Initially on the various original Minis but these days a lot of what he does is on the new, current, variant as well.
He confirmed my fear/thinking. The way the transmission fluid in the gearbox is sealed is by means of the seal (which we replaced) but also the shaft itself sits in a very tight bush. That bush was most likely worn.
Long story short. With only one liter of transmission fluid in the gearbox, I drove the Mini to Ben. He put a new re-conditioned gearbox on my Mini. Swapping gearboxes on a Mini without it being on a lift is not for the faint of heart. I for one, was not even going to attempt it. On the old Mini, it was dead easy. And a lot less heavy!
Also, Ben doesn’t sell recondition gearboxes stand-alone. He installs them always himself. As the Mini has done 120K kilometer he also put a new clutch set in.
Very happy with all of that. Although truth be told, the gearbox never gave me any trouble. No noises or anything.
Check out BHPian comments for more insights and information.
