R380 gearbox oil change

Barry Martin posted a note on the V8BB saying he found changing the gearbox oil on his RV8's R380 gearbox a much less arduous task. Here he explains how. (Aug 07)

I agree with everything Peter Garton has written in RV8NOTE271 but find it a less arduous task than he describes and one I can complete in 30 minutes or so. One most important point for anyone contemplating changing their gearbox oil on their own is to be aware that the later R380 gearbox has a Torx socketed filler plug (on the offside/UK driver's side of the gearbox) which will actually allow a certain sized allen key to fit and feel reasonably correct. Beware, if the plug is very tight or 'heat secured', you can very easily end up stripping the Torx socket and have a plug which is now next to impossible to remove as it is almost flush with the gearbox casing. The Torx bit required is very large, not commonly stocked by many motor accessories shops, but Halfords do have them. From memory I believe it is a T55. Needless to say, ensure the filler plug is slightly loosened before draining the gearbox, if you drain first and then have problems removing the filler plug you are up the proverbial creek! Incidentally I think the earlier LT77 box has a square headed (male) filler plug.

Finally, thanks to Stuart for the excellent advice on updated gearbox and diff lubricants (posted 2-3 months ago) which I followed on my last change.

As this method seemed much easier, the Editor of the RV8NOTES series, Victor Smith asked Barry to post an additional note which would add more detail to help explain why he finds the oil change fairly straightforward. Barry Martin sent in a prompt note alongside..

As a sequel to the three notes on gearbox oil changes - the useful RV8NOTE213 contributed by Martyn Selwyn back in July 2004, RV8NOTE271 above from Peter Garton and this RV8NOTE272 from Barry Martin - we checked with Brown & Gammons at Baldock as to how they do an R380 gearbox oil change. Ron Gammons notes "we of course have the RV8 up on ramps and then you must remove the heat shield. We do not remove the cats as there is always a risk you will damage a cat in that process and they are a costly item to replace. Filling with an oil pump as Barry Martin suggests is right or you can use an oil syringe for filling the gearbox to the correct level".

He added that "as gearbox oil changes are not a frequent activity, surely it would be an item where many RV8 enthusiasts would prefer to take their car to a specialist like B&G or Clive Wheatley who have the ramps and the necessary sockets and oil pump to enable the job to be done easily. It is the type of job you can book in for early morning, arrive early and allow the exhaust system to cool down and then the car can slip into the workshop so the job can be done rapidly and then very soon you will be on your way home!" It is a thought although Barry Martin comments "some members do gain satisfaction from working on their own classic vehicles".
R380 oil change with a fluid transfer pump
I first warm up the R380 gearbox to allow better oil flow when draining the box. Then I use axle stands either side at the front of the car (chocks at the rear wheels with the handbrake on) to gain easy access to the front couplings of both cats. Undo the two bolts on each coupling release the cats. As they are still attached to the rear section of the exhaust, so support carefully without allowing them to drop thereby breaking the sensor wires. It also helps to remove the forward most rubber exhaust hanger on the right hand side.

The bolts can now be removed from the cat heat shield - don't miss the one in the centre at the back - and then the heat shield can be carefully moved away. At the right hand side of the gearbox the fill plug is now accessible on the gearbox casing side and the drain plug close by at the base of the casing. Place a suitably large container underneath the gearbox drain point and then remove the filler plug (Martyn Selwyn says it is a Torx T55 socket in RV8NOTE213) and then the drain plug and allow the oil to drain. The car can now be raised and the axle stands removed to lower the car to level ground. Allow a few minutes for the gearbox to drain completely. Raise the car and replace axle stands to gain access to the filler and drain holes once more. The drain plug should be refitted, using a new copper washer available from any Land Rover dealer at £1.00.

Refilling the gearbox is difficult if you use the 1 litre tubed container in which the new lubricant is supplied because the space at the side of the gearbox is limited. I would recommend a fluid transfer pump (available on ebay at around £10 to £20) or a smaller container with a tube. The manual states that the gearbox is full when the lubricant starts to flow out of the filler hole of the gearbox but this, of course, is with the vehicle level. The RV8 Repair Manual states the capacity for an R380 is 2.9 litres without the oil cooler. If you wish to be spot on with the oil level, the only sure way is to slightly overfill the gearbox, by lowering only the left hand side of the car, which tilts the gearbox away from the filler hole. Removing the right side stand and gently lowering the car to level out completely will allow the excess oil to drain from the filler hole to achieve the correct level. I feel it is a dangerous practice to use four axle stands (one at each corner) to achieve a level car as a way of saving the constant raising and lowering of the car and would advise against. So having achieved the correct oil level, then raise the car from the right hand side first to prevent the oil from tipping out of the filler hole. Once the car is on one stand (the right hand side) the filler plug can be fitted. Then raise and fit the left hand side axle stand and start a reversal of procedure by refitting heat shield and cats.

Phew! - that was much worse to write than to do, but I hope it makes sense.

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