Changing the oil on a type R380 gearbox

Peter Garton (Woodcote Green 1238) from Germany provides a useful guide to a gearbox oil change. (Aug 07)

At first sight this simple job is certainly not so simple since without a ramp or pit, the job is impossible. In addition one requires a blow-lamp plus adequate tools to get the gearbox nuts undone. The heads of the two plugs - the gearbox filler and drain - are located out of sight on the driver's side of the gearbox as you can see in the photo above.

Removing the righthand cat. (Photo: Peter Garton)

They cannot be accessed without first dismantling:
> The right hand cat and part of the exhaust which has to be removed completely (heat required to loosen the joint and get the thing off) plus the cat connections/sensors.
> Loosening the left hand cat at the front end.
> Removing the cat heat shield completely.

Cat heat shield is removed completely. (Photo: Peter Garton)

The heads of the two plug are different - the top one (filler plug) is square and a quite a challenge to undo and the bottom one (drain plug) requires a 32 mm spanner! To undo the square filler plug requires an exact sized socket otherwise it will round off the faces of the nut very easily! It is done up extremely tightly and requires penetrating oil. Firstly, slightly tighten and only then attempt to unscrew it!

Remove the drain plug which is again tight but is at least a normal headed bolt. This drainage bolt has a magnet on it and so one should withdraw it very carefully. As one can see from the photo, there is a "shaving brush" coating of fine metal shavings attached to the magnet after only 20,000 kms.

Shaving brush coating of the magnetic drain plug. (Photo: Peter Garton)

After cleaning the magnetic surface, replace the drain plug with a new compressible washer. The capacity of the R 380 gear box is approximately 2.5 litres. New oil used is Castrol fully synthetic manual transmission oil: SMX-S SAE 75W-85 API GL1-4.

Filling the gearbox with the plastic bottles and plastic tuning. (Photo: Peter Garton)

As the photos show, the fitter at my workshop is squeezing the 500 ml plastic bottle after inserting it into the filler hole. One fills up the gearbox until the oil flows steadily from the top hole. Wait a short while for the oil to spread itself around in the gearbox and reach a natural level and then top up again to be sure. Then reassemble the parts removed to gain access to the filler hole and drain plug!

Frankly speaking, since carrying out the gearbox oil change I have not noticed any difference in the gear change itself. The gearbox change is notchy anyway and one has to watch the change from 3rd to 2nd making sure the clutch is really firmly pressed right down to the floor!

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