964rh

Hi

I'm looking at changing my engine oil DIY and was going to have a look at doing the gearbox as well.
Tried to get some info on this and couldn't find any. Has anyone got a DIY for the C4?
Also, is it just a case of changing the gearbox oil as per the C2 or is it different?

Thanks

Rob

Johnny G Pipe

Hi Rob
I changed my gearbox oil last year for Mobil 1 SHC 75W90. No big problems specific to the C4 as I understand. I used a funnel and a length of garden hose to fill, with an assistant holding the funnel from memory above the engine, with the hose fed down to the gearbox filler.

Number one rule is making sure the filler plug isnt seized before draining out the old oil of course. I think the filler is an allen socket.

Rocket Rob

One addition - the drain and filler plugs require a 10 mm allen socket.

964rh

Thanks everyone.

I got a bit confused when I read the capacities page on porsche964.co.uk and it quoted front axle (1.2LTR) and rear axle (3.8ltr). Thought I'd got two gearboxes to drain and fill.

What is the capacity for the gearbox when refilling?

Rob

Johnny G Pipe

Ah, right: Again from memory the gearbox (rear axle) was indeed around 4 litres. The front axle refers to the front differential, which afaik is the same principle, just smaller amounts. Its on my to do list, but pretty low down, so I can't offer any practical tips.

I havent seen many threads on rennlist the necessity or process of front diff oil change. I've heard of gearbox failures but never C4 front diff failure..

Rocket Rob

Rob,

This is the procedure that I used. I had looked up the "rated" capacities of the front and rear axles. I then purchased 7 quarts of Mobil 1 gear oil just to be safe. I heated the oil in hot water to make it easier to pour. I didn't keep exact records of how much was used but 7 quart bottles were sufficient and I have some extra to top off in the future.

964rh

Thanks Rob

Stupid question but how do you know when you've put enough oil in the gearbox?

Rob

Johnny G Pipe

The filler is the upper level. When it starts overflowing, thats enough! Just take it easy towards the end of the 4th litre bottle.

This wouldn't be so bad if trans oil didn't smell like tomcat pee, and have the amzing ability to get absolutely everywhere..

tgage

One more thing.... Change the oil on a day when you want to get out of going somewhere with the CFO. You just need a few drops of old gear oil on you before she is suggesting she can go w/out you. BTW... the CFO had me pitch my work jeans after that.

I've found changing the front to be a bit faster then the back.

tom

964rh

Tom

That's partly why I wanted to try DIY

ThunderboltVIII

No kidding. Gear oil smells like an NYC subway elevator.

I use an electric pump now, and elbow length gloves.