Porsche Enthusiasts Club Forum

Hi Folks -

Seeking advice here - I can accomplish most things on my S2, like engine oil/filter/air/plugs etc changes as the tools to do these things are pretty simple and are in my garage tool kit. The belt changes I leave to my local Porsche know-all who has all that of all knowledge to do a good job.
The gearbox oil change looks like a simple job and I would like to do it myself but am lacking the buster tools to do it - it needs a 17mm allen key for the two lock bolts, or the suitable size ratchet-wise. Both I can purchase but what technique is the best way to approach this tool wise...?
This oil change is supposedly done every 60,000mls by Porsche service advice...

Much appreciated -

Dave
CT

a very high quality Allen key and a long strong tube, they will be very tight "very tight" and make sure you can undo the filler before undoing the drain plug.

Go to http://www.clarks-garage.com, click the link on the left hand side for "Garage shop manual" and scroll down to "Changing Manual Transmission Fluid" and the whole procedure is on there. Even I managed it without messing it up. I did need a LOT of force to get the plugs out though. I tapped the end of the ratchet with a lump hammer in the end. I can't image being able to do it with an allen key. I used a cheap ratchet and a 17mm hex bit - see item number 160657796725 on ebay

Cheers,
Bryan

The thing to note is that they shouldn't be tight at all, the plugs are tapered and should only be tightened to 25nm. I would recommend that you use the correct allen key and clean out the plugs to ensure a good fit because if they are too tight it's very easy to split the sides of the plug.

Thanks all for advice and comments. I have got myself today a 1/2" 17mm allen socket and wrench bar.

There is a German fellow on YouTube I have found (under 944S2 maintenance) that did a gearbox oil change and ended up having to remove the back box and then using a hammer bolt driver to release the stubborn bolts, when all other attempts had failed (worth a watch).

I will post progress...

Dave
CT

Hi Folks - Progress report thus:

Both allen bolts loosened! (loads of WD...) I had jacked the back end up (on the flat part of the diff housing) but allowing the tyres to be still slightly grounded. With my 17mm allen socket and 1/2" jemmy bar plus a similar length of tubing, the bolts came loose. Very satisfying!

On inspection of the bolts, one seems to be magnetic (previously fitted incorrectly at the top...?) and both seem have a non standard allen key drive fitting. It would appear that the correct removal of said bolts is by way a Porsche tool, specific for the job...



Pic show the bolts removed, the l/h from the drain plug and the two splits. The r/h came from the filler hole and not too bad condition, but I need to replace both - if you look closely, you can see why a normal 17mm allen key/socket doesn't effectively grip the sides of the plug...

Hoping you are all having a great weekend...

Dave
CT

To change my gearbox oil I used a standard sump plug remover I had in the tool box and slowly released it with socket and pry bar and adding pressure to the bar slowly.
Make sure you replace the plugs with fresh ones every time, they're approximately a fiver each from an OPC. As stated previously, make sure you removed the top plug first in case of threading.

Good job! Looks like that's progress of the right kind. FWIW, I have never had a problem getting the plugs out of my S2 gearbox and have re-used them many times without problems. But I do change the gear oil every year so they are never in there long enough to get very tight. Getting the new oil in is always harder than getting the plugs out!

New gearbox oil should mean tighter, smoother shifting and a slightly quieter and smoother car. If the existing stuff has been in there for a long time then the improvement should be significant.


Oli.

Thanks Oli for your reply.

I am waiting for the new allen bolts to arrive as OPC are out of stock but they should be here shortly.

I have a few quick questions that perhaps you can help me with in the meantime:

1. When tightening the allen bolts - do you torque them or just 'nip' them tight? Is using Loctite or plumber's tape necessary?

2. What is the best way (that you use) to refill the trans-axle? I don't have one of those pump kits...

3. What level should the oil be once filled? Porsche spec says somewhat below the filler (10mm?), others' advise when the oil dribbles/overflows from the filler itself. NB: I can understand that the car itself should be on level ground...

Thank you for your advice...

Dave
Cape Town

Dave,

Good Q's.

- I just nip the plugs tight. I notice that AndyG has quoted the official torque of 25Nm, but I don't use a torque wrench on them - just a short ratchet.

- Refilling the casing is the hardest part of the job. The oil that I buy comes in 1l bottles with a plastic nozzle on the top and I attach a long length of clear plastic tube onto the nozzle and poke the other end of the tube into the top hole of the gearbox (don't forget to put the lower plug in first!), turn the bottle upside-down and let it drain down the tube. Making a hole in the bottom (i.e. highest part) of the bottle is necessary. It also helps immensely if you stand the bottle of oil in a tub of boiling water beforehand so it is warm and thinner and runs more easily.

- I fill until it dribbles out of the fill hole and have never had a problem. You'll have the car jacked up and the wheel removed so you can tilt the car toward you (i.e. lower than if it had the wheel on) and thus slightly lower the fill hole but it doesn't make much difference.

Let us know how you get on.


Oli.

That's cracking advice Oli!

I am sure any oil degrades over time and although engine oils have to work a lot harder, so much so gearboxes also. But neglected!

Thank you for the sage advice -

Dave
CT

I'm told that oil doesn't degrade much over time; the problem with using it for longer periods is that the long chain hydrocarbons in it get munched up and shorter chains are formed. These are less effective as lubricants and need to be changed. The munching is a simple mechanical process; a long molecule gets caught between a piston and cylinder wall, or in a pair of gearwheels, and is cut in two.

Whatever the explanation, if your existing oil is more than a couple of years old and the new stuff is half-decent, there should be a good improvement in store!


Oli.

Hi Folks

Transfusion for the gearbox. 2.7 litres of 80W-90 GL-5 EP

Quite an amazing test drive after the oil change today! I always thought that my S2 was quite quick, relatively speaking, but crikey, I am impressed...

Dave
CT