17/09/2009

How to change transmission oil on a Porsche 944



THE WHY?

If your 944 is 25 years old like mine with just over 120,000 miles on the clock then you may have noticed that the gear changes are not as smooth as they once were or maybe your gearbox is whining a bit. Then it's quite possible your gearbox / transmission needs some fresh lubricant.

THE TASK

Quite a simple one really. This is what you'll need.

17mm Hex bit
Torque wrench
Anti-seize thread lubricant
Swepco 201 gear oil (Approx £50) - You get 3.8 Litres in the bottle, the transmission needs 2 Litres
A large syringe
Bowl to catch old lubricant

THE HOW TO


(Amateur mecahnic Job Time approx: 1 hour)

If your transmission is still attached to the car then it's probably best to give it a 10-15 minute drive to warm the old oil up so that it flows out more easily. My transmission was already off the car so I just had to make sure it was on a level surface. The transmission is located under the rear of the car. Take an empty bowl and place it under the left hand-side of the transmission ready to catch the old oil. On the left side of the transmission you will find two identical oil drain plugs situated to the right and below the drive shaft mount.



Start by cleaning off any dirt or rust around the threads on both drain plugs, give them a spray of penetrating oil too. Remove the upper plug first (in case the lower one is seized then you haven't lost all your oil with no way of putting fresh oil back in). Then remove the lower plug using a 17mm hex key, the oil should then start to flow out. Once all the old oil has flowed out stick your finger in the hole and feel around checking for metallic particles left in the bottom of the transmission. If there are then your tranny may need a little more attention than just an oil change. Now is a good time to inspect the condition of the drain plugs. Mine were pretty old and roughed up so I decided to change them for new ones, only a couple of quid each from Porsche. Notice the tapered thread on the drain plugs.



Now apply a little anti-seize thread lubricant to one of the drain plugs and tighten it into the lower hole to a torque of 20Nm. Now fill the syringe with Swepco 201 gear lube which I bought from here and pump it into the upper right hand hole. Repeat until the oil comes level with the bottom of the hole you are putting the oil into. Once you're there apply the same anti-seize thread lubricant to the remaining drain plug and tighten to 20Nm. Job done.

18 comments:

  1. How much oil does it take to fill the box?

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  2. The transmission takes 2 litres of oil. You get 3.8 litres in the Swepco 201 bottle.

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  3. what does it mean if there is metal at the bottom of the transmission?

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  4. Means you've got some kind of impending problem on your hands I would say, most likely the pinion gear gradually disintegrating if it already hasn't. Is the transmission working?

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  5. yes it works but there is a small whining sound coasting at speeds above 40. I hear a transmission fluid change should clear that up.

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  6. Well you can only give it a go and see if it works, I think if I was in the same situation I'd probably do the same thing.

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  7. Ok. What is your opinion of mobil 1 or royal purple transmission fluid? I was thinking of wither one for the fluid change.

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  8. I have used neither of those, everyone I spoke to on the forums used Swepco which is what I used. Been smooth so far.

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  9. What is the transmission fluid capacity for a 1988 944 n/a? I've heard 2 quarts and 3 quarts.

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  10. You need 2 litres = 1.75975326 Imperial quarts

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  11. What is the oil capacity for an 88' 944?

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  12. Should be the same, as far as I am aware the only differences between early 944 transmissions and later ones is the addition of a speed sensor, different mounting brackets and maybe some slight differences with the gear ratios. The only big differences occur with the turbo models where you have the addition of an oil cooler too I believe and stronger internal components to cope with the increased torque.

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  13. I have recently had my 944 serviced and there is now a small oil leak from the transmissions drain plug. Does the drain plug have a washer/seal which may have been damaged when the oil was changed? Or could the plug just need tighting or have been damaged?

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  14. There is no washer, the drain plug has probably been removed loads of times before so the thread won't be as air-tight as a new one. The garage should have coated the thread in an anti-seize sealant anyway before re-inserting it which should also act to seal the plug too. But if the thread is worn enough the sealant won't be enough on its own. Best thing to do is replace the drain plugs with new ones and coat the threads with anti-seize. Problem you have now is that if it is the bottom drain plug that is weeping you risk having to replace that brand new transmission oil, top one not so bad as that's only the filling hole.

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  15. MY transmission turned out to take 3 quarts of fluid not 2 like you said. Is it different from yours to my 88' non-turbo?

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  16. I'm just going by what the official Porsche manual says, as a guide when the car is sitting level the oil should come almost level with the upper filling hole.

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  17. I suggest removing the top plug first. If you drain it and then find the top plug is seized, that will be trouble.

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    Replies
    1. Yes, makes sense, I've updated the procedure.

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