IN FROM THE TOP - GEARBOX OIL CHANGE.

[Southernboy]

....After deliberating the necessity of carrying out a gearbox oil change, I've decide to go ahead.
The one aspect of this task is the PITA it is to fill with fresh oil. Those who have done this will know the difficulty in getting sufficient angle to pour the fresh fluid into the filler hole which is situated on the side of the box. The awkwardness generally results in a messy job to some degree.
Having recently been looking at servicing the shifter bushings, and read in the description about being able to do the job without removing the gearbox... Part of the process is to remove the gearshift shaft from inside the car... This led me to thinking that perhaps it will be more practical to fill the gearbox from the top... ie. from inside the car. I have removed the gearknob,the leather gaitor and the foam surround below that, and finally the rubber sealing boot... This gave a clear view down on top of the gearbox... I have used a 500mm long piece of flexible hose which passes through the lid of the bottle of oil and needed to be heated to soften it to pass over the plastic pour spout / tube which comes as part of the oil bottle. I have used a strong cable tie to secure it below the lip of that tube, and then drilled a 12mm hole in the plastic cap of the oil bottle and refitted that to the bottle. I have tested the set-up for leakage by turning the bottle up and plugging the flexible tube whilst giving the plastic bottle a squeeze... it's perfectly sealed, and no oil has managed to pass anywhere...
I took the other half of the 1m of flexible tubing and passed it through the gearshift hole and down the right side of the gearbox... it passes through and around without much fuss and is more than long enough to reach the gearbox filler plug with about 250mm still inside the car and above console level...
So, afetr a short sprint tomorrow morning to heat things up, I will drain the box and do the refill from the top... Unscrewing the plastic cap and removing the complete product tube to which I have cable tied the flexi-tube and simply popping it into the next full bottle... I'll place a catch pan under the gearbox so that by the time I've pumped 1,5 lt of oil down, it should be overflowing below and the excess being caught in the catch pan... Also, it can be done with the car in it's normal position - ie. standing on all fours and level...
I'll take a good rag into the car with me though - just as a precaution...

[Del]

Sounds an ingenious method. I agree it is an awkward little job as the Z3 is like a tightly sandwiched E36 with the gearbox closely fitted in a recess under the car. I used a 100ml syringe and a bit of plastic pipe to get the oil in, but as you say it was messy

[Southernboy]

.... I'll let you know tomorrow how good this method actually was... "the best laid plans" and all that...

[Daz3]

Sounds like a good plan I'll keep watch as it's on my agenda.

[Southernboy]

......here's the bottle I've prepped for tomorrow...
You can see the "lip" of the bottle tube just above the cap... under the cap is the cable tie holding the fleexi-tube onto the hard plastic bottle tube...

[Del]

Definitely worth doing in my view to care for your important parts in the drivetrain i.e. the gearbox and diff. Changing these fluids is not on the service list at all for modern BMWs I was in my local BMW main dealer a few weeks back and a concerned X5 owner (car 7 years old) was querying why the gearbox oil hadn't been changed and the rather "limp" response from the service manager was that "it simply wasn't on the servicing list". Seems a similar situation for their fuel filters.

[Southernboy]

.... well generally the transmission oils are "Lifetime oils"... meaning they don't get changed - ever ! In my experience, there's nothing in this life which lasts forever...

[Bonzo]

.... well generally the transmission oils are "Lifetime oils"... meaning they don't get changed - ever ! In my experience, there's nothing in this life which lasts forever...

Except your wife's memory!

[Southernboy]

.... Yes, that would be true... fortunately she lives in Vancouver...

[Southernboy]

.... After a 10km run to warm the box up...
Raise car and remove the gearbox drain plug... lower car and allow 45mins to drain while haveing a traditional bacon & eggs with toast breakfast...
Raise car again, re-fit drain plug & remove filler plug... feed the flexitube from the top and into the filler hole about 130mm...
Place catch pan under filler plughole... lower car and get seated inside...
Tip up first bottle and squeeze gently to get the oil going down the tube... Once about 1/2 the contents are out the bottle, use a Stanley knife to cut the bottom off the bottle...
Let gravity do the work...and keep filling with the 2nd and 3rd x 500ml or until you hear the overflow trickling into the catch pan...
Prop the filler bottle in the gearshift / console hole while you go back under after raising the car... remove the tube ffrom the fill hole, and allow it to drain into the catch pan while replacing the filler plug...
Make sure the flexi pipe is empty of oil and wipe the end off.... Clear everything from under the car, and lower...
Remove the aparatus by withdrawing from inside the car, and replace the gearshift rubber boot, the foam plug, gaitor and knob...
It's the easiest way to do this... from the top... and not a drop of mess !!!

Tools:- 17 socket and 1/2" ratchet drive / Stanley knife / 1.1m of flexible hose / Catch pan and a rag / Hydraulic jack.

Prepping the first bottle:- 1.1m of flexible plastic hose which will fit tightly over the hard plastic spout which comes with the product.
The flexi-hose needs to be pushed over the hard plastic spout all the way down it's length but leaving aprox 15mm of the bottom of the hard plastic pipe spare. That 15mm will clip into the bottle top insert which comes with the product... You will need to drill an 11mm hole in the center of the bottle cap so the flexi-hose can pass through it tightly
The cap is screwed back onto the bottle securely... and you're ready to go...

Obviously, one could simply use a funnel to which you can securely attach the flexi-hose too...

Feed the flexi-tube into the filler hole...


First bottle... agentle sqeeze..


Allow gravity to do it's part... and keep topping up with bottles 2 & 3...


Until you hear it trickling into the catch pan...

[Mint]

Brilliant Barry, well done. But that's not a catchpan it's a saucepan

[Southernboy]

..... yeah.. It was handier than digging down to retrieve my plastic one...
I must say, going in from the top is the only sensible way to do this task... There just isn't any room under the car to tilt the bottle up enough to get the stuff in... This way it's a breeze...

[Althulas]

I love improvisation it's a good job your wife is in Vancouver so as not to use that pan around your head . I once needed a small trowel for a small plastering repair and did not have one to hand and I could not be bothered with the trip to Wickes so I improvised with a silver cake slice the expression on my wife's face was priceless.

[Daz3]

Great work Barry I'll be stealing this one soon

[Southernboy]

.... Boy will be boys....

[pingu]

Well done. I'll use this method next time. Just two points...

1. ALWAYS undo the filler plug before the drain plug.
....Two reasons -
.... a. You may not be able to undo the filler and you are left with a car with no gearbox oil
.... b. Air can get in and avoids glugging.

2. Instead of lowering the car to get it level, raise the rear. It means that you have undercar access all the time and their is less jacking (which is a PITA).

[Southernboy]

I did consider point #2... but with a power bar on the socket it was dead easy for both plugs...
Raising the car means raising both sides to get it level left to right, but not front to back..... I guess if one has access to a pit that would be first prize..
Oddly, it didn't glug... just gushed warm oil, but I get your point...

Thankfully, I can forget about this task for a few years now...
Someone asked me the cost of the oil... around £11.50 for 3 x 500ml. Castrol MTF 75-85 GL4.

[Southernboy]

...... for those guys who are looking at doing this....

[bertiejaffa]

I'm going to be doing this shortly Barry - I know there is no ring to replace so what if anything did you put on the drain and filler plugs when you put them back in to make them tight? Or did you just torque them up?

[Southernboy]

The drain plug has a copper or aluminium washer... can't recall if the filler has one too.. But obviously replace the drain plug before filling and keep filling until it overflows out the filler hole... then let it settle and replace the filler plug.