24k-30k-60k Service - Gearbox oil change


Here are links to the other parts of the servicing:

1. 60k service schedule
2. Spark Plugs
3. oil and all filters
4. dizzy rotor & cap & belt
5. gearbox oil
6. ISV valve clean
7. PAS belt check



A gear oil or transmission oil change is recommended by Porsche at 60k miles. If you're finding that your shifts are a bit stiff, that they possibly crunch a little then changing the oil can help. Replacing the engine mounts also can help here too.

This is a very simple job but it's best to devise a method for getting the oil into the box before you start. First of all there is good old gravity which is very time consuming. Better still is converting something like a brake bleeder kit like the type sold by Gunzon. For myself, I hacked a brake bleeding kit with the use of compressed air which made it all even easier. My tubing was a bit thin though and when I do this again I will be sure to use much wider diameter tubing to help speed up the filling process even more.



You will need a decent 10mm hex socket on a ratchet with a long handle or alternatively a breaker bar. You might get awayw ith it with an elley L key but its far from ideal.

You'll need 4 litres of oil. Mobil 1 SHC 75W-90 is vey common as is offerings from Redline. Also, a bucket or tray or container to catch the old oil.

A Phillips screwdriver for your gearbox undertray.

A length of tubing, around 3/4" ID. You can get this sort of thing very easily form somewhere like from Homebase. Alternatively modify a brake bleeding kit. A funnel will help on the end of this as well.

Finally you will need 2 new sealing rings for the drain and fill plugs. These are the exact same items used on the oil drain plugs: 900 123 118 30


First of all go for a short drive and get the oil up to working temperature.

Jack the car up and get it on stands so that it is level. Remove the gearbox undertray undoing the Dzus fasteners. Straight up on teh underside of the box is the drain plug.

And to the nearside or left side is the fill plug.

Crack the fill plug open first and just loosen slightly or oil might start to pour form here. It might need a sharp tug. best to use a long ratchet or a breaker and a 10mm hex or allen socket driver.

Crack loose the drain plug and then undo and whip away quickly. Have your container directly below at the ready.

With the car level allow it all to drain out. I left my car for well over 30 minutes.

Here are your two plugs. The drain plug has a magnetic stump on the end which will have attarcted and collected metal shavings from the gearbox. This is normal, just clean them off. If there is an excessive amount there however then maybe take a good look at the oil as well and consult a specialist if necessary. Obviously a large quantity of metal shavings would indicate that all is not right.

Fit the new metal sealing rings to both plugs, give them a quick clean and then when all the oil is drained fit the lower drain plug back on and tighten it to 22 ft/lb (30 nm)

Here is my Gunzon brake pressure bleeder, the type that fits to a car tyre and uses its pressure to force brake fluid through the cars system. I modified it by screwing the lid onto the oil bottle ... just by chance it was a lucky fit.

I then went a stage further and attached an air hose to it.

I took the precaution of lowering the pressure to around the 20psi mark. You do NOT want 110psi going through a thin little plastic bottle !

Whatever you use, the trick is simply to feed the hose a little way inside the fill hole and then get the oil down the tubing and into the box. If you use a straight hose and funnel then you can run the hose through the nearside rear wheelarch, have the funnel up high and pour the oil in slowly.

With my method I was able to press the gun and force the oil in at a much quicker rate. I could also see the little slit window on the side of the bottle and see how much had gone in and how much was left to go.

All in all, I put around 3.6-3.7 litres in and then it started to drip back out of the fill hole. That's the exact right amount that is stated in the workshop manual. Pull away your hose and then replace the fill plug with its new sealing ring and again, tighten to 22 ft/lb.

Replace your undertray and then you're done.




The Jackals Racetrack http://www.jackals-forge.com/lotus 1998 Richard Morris