Replacing gearbox oil

[sawood12]

I'm gong to replace my gearbox oil with Swepco which seems to get rave reveiws from those who have used it. It seems a pretty simple operation - I am going to employ the long length of hose & funnel technique to get those last few drops into the gearbox, however I have a couple of queries:

1. I've read that it is pretty important to get the right quantitiy of oil into the gearbox as too much or too little will cause later problems. Is this true?

2. I've also read that you are better off replacing the oil when the gearbox is warm. Why is this and do people on ths forum agree?

3. Do I need to have replacement washers for the plugs at the ready or are the ones fitted reuseable?

Cheers.

 

[SteveSJS]

Drain plug on the bottom, filler half way up.
Filling to the point where oil is just oozing out of the filler is the right amount.

Carrying out the task when the gearbox oil is warm means it dreains quicker and easier as it flows more easily.

The washer should bea copper one - remove it from the plug then heat treat it. i.e. holding it in a mole grip or similar heat it with a gas torch or over a hot ring on the gas cooker. The flame will turn green as the washer heats up. When the washer is glowing plunge it into cold water to quench it. The washer will then have regained the necessary elasticity to be retightened to the correct torque and be leak-proof.

HTH

SteveS

 

[Kevin Welch]

On my S2 the plugs are a taper fit and therefore don't have copper washers. Make sure the allen key 'holes' are cleaned out to enable the allen keys to seat home properly as the plugs might be very tight. I needed a four foot scaffold bar used as an extension to undo mine.Remember to undo the top (filler) plug first as you don't want to drain the oil then find that you can't remove the filler plug to put oil back into the box.

 

[Guest]

i have just done mine , what a prat of a job finding my 17mm allen key , so i improvised , got a long bolt with 17mm head popped it in the vice and bent the bolt half way attached a pair of molegrips to bar and hey presto , ,,,,,, then after topping up a small oil bottle with a nozzle several times and hanging upside down trying to get it in the gearbox i finally filled it up ,,,,,, put the oil back on the shelf and found my allen key ... hahahaha ,,,,,, short and stubby i like my new one better so popped the one i made back in the vice with a long bolt along side it and welded them together , then grinded it clean and made a handle for it ... i now have a long reach 17mm bolt head on a long bar with handle ,.,,, does the job super ..

 

[John Sims]

ORIGINAL: porker9xx

.......got a long bolt with 17mm head popped it in the vice and bent the bolt half way attached a pair of molegrips to bar and hey presto ....... found my allen key ......i like my new one better ......

I thought you were going to say that you then turned your allen key into a bolt. []

Beaky is being refilled with Swepco while he is away. []

 

[Mikie_gb]

Hellfrauds sells a 17mm hex socket attachment. The infill plug was very tightly wedged and had me all but dragging the car backwards out the garage by the gearbox to loosen it. Then getting the sulpher stinky oil in was even more of a treat. It went everywhere and the smell managed to permeate the whole house. Did it make a difference? Nah. It was silent before and is still silent. (having said that it will immediately start to howl)


See http://www.clarks-garage.com/ under garage manual - Transmission

 

[sawood12]

ORIGINAL: SteveSJS

Drain plug on the bottom, filler half way up.
Filling to the point where oil is just oozing out of the filler is the right amount.

Carrying out the task when the gearbox oil is warm means it dreains quicker and easier as it flows more easily.

The washer should bea copper one - remove it from the plug then heat treat it. i.e. holding it in a mole grip or similar heat it with a gas torch or over a hot ring on the gas cooker. The flame will turn green as the washer heats up. When the washer is glowing plunge it into cold water to quench it. The washer will then have regained the necessary elasticity to be retightened to the correct torque and be leak-proof.

HTH

SteveS

Don't you want to anneal the copper i.e. to soften it, rather than harden it thus making it more brittle? Annealing makes the metal softer which is what I thought you would need to create a good seal and is achieved by heating up the copper to cherry red colour and allowing it to cool down as slowly as possible (in industry they just switch off the oven and allow it to cool naturally over 12 hrs or so) to give the metallic grains maximum time to grow and enlarge. Quenching the copper will lower the metal temperature instantly therefore resulting in very small mettalic grains therefore making the copper brittle and susceptable to cracks.

Anyway i'm hoping i've got the tapered plug without the copper washer.

The method for getting the oil into the gearbox I was planning on emplying is to use a length of flexible transparent plastic pipe and a funnel. I would therefore raise the funnel to a height that is taller than the gearbox filler hole then pour the (warmed) oil into the gearbox (measured quantity from a jug). Once full I can then lower the funnel to just below the filler hole and any excess will pour back into the funnel which I can then pour back into the jug. Sounds simple in principal but I bet I end up with gearbox oil all over my drive!!!

Do you bother torquing up the gearbox plugs or just tighten them as much as you possibly can??

 

[Diver944]

ORIGINAL: sawood12

Sounds simple in principal but I bet I end up with gearbox oil all over my drive!!!

Can I recommend a good friend of mine http://www.cobbleclean.com/ []

 

[944Turbo]

I think here is the answer and for under a tenner
http://www.porscheclubgbforum.com/tm.asp?m=133994&mpage=1&key=tools&#133994

 

[John Sims]

Not wishing to scare people but I was advised by a mechanic that gearbox oil can be carcinogenic (as is Coppaslip). Best to wear gloves.

 

[Fen]

I think I knew that on gear oil. Certainly hydraulic oil is as that was impressed up me on a forklift course I did nearly 20 years ago. I can't say I knew about copper grease, but I do tend to wear gloves to use it as it's such a pig to get off again if it gets on hands. Experience tells me it's a really bad idea to rely on a towel to get the last of it of...

 

[PRJ]

ORIGINAL: John Sims

Not wishing to scare people but I was advised by a mechanic that gearbox oil can be carcinogenic (as is Coppaslip). Best to wear gloves.

Triffic - I had to apply Coppaslip to vitually every component when I assembled my Caterham a couple of years back and often just used my fingers. Better get my Will updated then []

 

[Guest]

ORIGINAL: sawood12

ORIGINAL: SteveSJS

The washer should bea copper one - remove it from the plug then heat treat it. i.e. holding it in a mole grip or similar heat it with a gas torch or over a hot ring on the gas cooker. The flame will turn green as the washer heats up. When the washer is glowing plunge it into cold water to quench it. The washer will then have regained the necessary elasticity to be retightened to the correct torque and be leak-proof.

HTH

SteveS

Don't you want to anneal the copper i.e. to soften it, rather than harden it thus making it more brittle? Annealing makes the metal softer which is what I thought you would need to create a good seal and is achieved by heating up the copper to cherry red colour and allowing it to cool down as slowly as possible (in industry they just switch off the oven and allow it to cool naturally over 12 hrs or so) to give the metallic grains maximum time to grow and enlarge. Quenching the copper will lower the metal temperature instantly therefore resulting in very small mettalic grains therefore making the copper brittle and susceptable to cracks.

The alternative (which I have always gone for) is to buy a brand new shiny copper washer and use it. I've never heard of anybody trying to save the few pennies by trying to re anneal an old one before.

 

[berg944]

achieved by heating up the copper to cherry red colour and allowing it to cool down as slowly as possible (in industry they just switch off the oven and allow it to cool naturally over 12 hrs or so) to give the metallic grains maximum time to grow and enlarge. Quenching the copper will lower the metal temperature instantly therefore resulting in very small metallic grains therefore making the copper brittle and susceptible to cracks.

I think you are getting confused with hardening and tempering steel. Copper "work hardens", this means it goes brittle through any movement within its structure. Heating to cherry red will relieve the stresses and normalise the structure and make it soft again (annealing), so no need to quench.

[8|] Hope you did not mind the lesson.[X(]

Mike[:'(]

 

[sawood12]

That's what I said. To anneal (soften) the copper you heat it up and allow it to cool as slowly as possible to soften it. If you were to quench it then you would end up with a harder but more brittle material. Work hardening is a product of manually working the copper where it becomes stiffer and harder through fatigue therefore you need to periodically anneal the copper to soften it again and once you've finished working the material you might want to quench it again to toughen the final product. For a sealing washer you would want a soft material that wouldn't crack under the stress of tightening the nut against it. Cracks in seals isn't a good thing!! But I agree with James - best just to buy a new washer.

 

[sawood12]

Replaced my oils today. The gearbox was a doddle in the end although I had to buy a 17mm allen key. I used the oil syringe pump thing in the link above which made the job easy. The old oil came out looking like it was new - clear as a whistle. Does it get dirty like engine oil? I was also unprepared for the colour of Swepco - it is bright blue just like windscreen washer stuff. Couldn't get my oil filter removal tool around the oil filter though due to the pipe that runs right next to the oil filter. I'll have to get myself another type that I will be able to get around the filter and replace that in a couple of days.

All in all a two hour job max, thanks for the advice above.

 

[Kevin Welch]

Glad you managed the oil change OK. Engine oil discolours because it picks up all the contaminants from the combustion process. Hopefully you haven't got any combustion in your gearbox.[][][]