# Gearbox Engine Oil Change ?



## perm (Oct 26, 2005)

Hi,
Goes anyone change their gearbox oil? This is not part of any service schedule however have heard can be a good preventative thing to do.

Your thoughts?


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## gatecrasher3 (Jul 21, 2006)

Yeah change it, why wouldn't you?


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## Ti22 (Mar 24, 2009)

It should be on one of your service schedules!. I'd change it at least every 2 years, regardless of the schedule anyway. 

It's also worth checking the level periodically.


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## rapidseven (Apr 26, 2007)

I change both every 4,000 miles, including the slave cylinder oil.

Its good practise, as dont forget the transmission is working just as hard as engine.

If you like and care for your car, then yes.

If your going to me moving it on, dont bother - let the next owner do it


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## tmagnet (Feb 27, 2009)

I wouldn't bother.
Engine oil has combustion gases in it from the way the engine works, which is one of the reasons why the oil is changed. 
A gearbox doesn't have combustion gases in it nor does it get as hot as engine oil does. So why change it?
Most cars now don't even have drain plugs on the bottom of the box as manufacturers don't even think it should be changed. The only time i can see it being changed is due to a driveshaft being replaced or if you are having problems with the gearbox.
I recently did an oil change on a 40year old gearbox...made no difference having new oil in there and the oil that came out didn't look too bad tbh, just smelt horrible


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## perm (Oct 26, 2005)

thanks for the views.
On the BMW MINI the view is the gearbox oil is for life so does not form part of the service schedule. ( regardless of age / mileage )

I have no reason to change it.... just want to keep everything working well as the car gets a little older ( 70K miles now ).... 

Can not work out if I should change it or just let sleeping dogs lie.


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## Bigpikle (May 21, 2007)

Changed the oil in the gearbox of my '69 MG last year but what came out looked no different to what went in! I was working on the overdrive so did it anyway but makes no difference in feel etc, but it is a 40 year old car :lol:

Won't bother on my modern cars if levels are fine.


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## trenchfoot (Jan 11, 2007)

Change it. Gears slowly flake metal off, and eventually you have yourself a load of sludge and particles wearing away at the selectors and other moving components.
Helicopters get their rotor gearbox oil changed and flushed regularly for that very reason. :thumb:

Some G'boxes don't have drain-plugs. If that's the case you'd have to remove the G'box, turn it upside-down and drain it through the filling point! If you can't be ar5ed to do all that then just make sure the level is okay


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## Judas (Jul 3, 2008)

trenchfoot said:


> Change it. Gears slowly flake metal off, and eventually you have yourself a load of sludge and particles wearing away at the selectors and other moving components.
> Helicopters get their rotor gearbox oil changed and flushed regularly for that very reason. :thumb:
> 
> Some G'boxes don't have drain-plugs. If that's the case you'd have to remove the G'box, turn it upside-down and drain it through the filling point! If you can't be ar5ed to do all that then just make sure the level is okay


no helicopters have it done because if they crash - everyone dies.........:doublesho

gearboxes........the risk is a bit less.......!


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## Neil_S (Oct 26, 2005)

I changed mine about six months ago, bit tricky, but worth it. I'd probably consider once every 5 years enough.


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## patmac (Apr 17, 2009)

I change mine every 6 months. On some cars the plug has a magnetic insert, when i changed the gearbox oil for the first time on my old MG zs i go some fright with the amount of iron filings on it. Since then with my new(old) car diff and gearbox oil is on a 6 month rotation. Only takes an extra 15 mins with the pit:thumb:


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## tmagnet (Feb 27, 2009)

patmac said:


> I change mine every 6 months. On some cars the plug has a magnetic insert, when i changed the gearbox oil for the first time on my old MG zs i go some fright with the amount of iron filings on it. Since then with my new(old) car diff and gearbox oil is on a 6 month rotation. Only takes an extra 15 mins with the pit:thumb:


Shouldn't have been that many bits of metal in the plug unless you're a bit of a gear cruncher? Sure there wasn't something else wrong with it?
As said before, I did a change on a 1960's g/box and the magnetic plug had very little metal attached to it...and i've heard the driver crunching the gears (and done it myself) plenty of times lol


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## PJS (Aug 18, 2007)

Assuming you use a top quality oil, rather than engine oil (often they'd use a standard 5W-30 or 40) then yes, change it periodically.
For the total cost of what it is for the oil and changing it, versus the cost of dropping/inspecting/repairing/refitting a gearbox, it's £30 (typically for an indy) well spent every 20-30K miles, especially if the car is older/used/being retained rather than traded at the 18-24 month mark.

I've used a couple now in the Accord, and after about 15K on the previous oil that was used, having just replaced again this time with Motul 300 Gearoil, by christ is the change much smoother, and less notchy.
So, if my experience is typical, then changing gearbox oil, even AT's, is definitely something that should be done without even batting an eyelid.

Let's put it this way, in whose interest is it to keep the gear oil in the box forever and a day? Yours or the manufacturer, who'll happily replace worn parts for a profit-improving fee?
I think it's high time people stopped conning themselves that lifetime oils, longlife oils, etc, etc are provided by the manufacturer for altruistic reasons, but because they figure by the time the car's out of warranty, the replacement parts aspect will kick in, under the "wear & tear" label.

If you're punting the car on within the warranty period, then you've nothing to concern yourself with after it's sold, but if it's a used car, or you'll be hanging on to it, then you should be proactive about maintaining the more expensive elements - engine and gearbox being but two.


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## Techgeek (Jun 7, 2007)

PJS said:


> Assuming you use a top quality oil, rather than engine oil (often they'd use a standard 5W-30 or 40) then yes, change it periodically.
> For the total cost of what it is for the oil and changing it, versus the cost of dropping/inspecting/repairing/refitting a gearbox, it's £30 (typically for an indy) well spent every 20-30K miles, especially if the car is older/used/being retained rather than traded at the 18-24 month mark.
> 
> I've used a couple now in the Accord, and after about 15K on the previous oil that was used, having just replaced again this time with Motul 300 Gearoil, by christ is the change much smoother, and less notchy.
> ...


agreed, i also think they say lifetime fluids to appeal to fleet buyers to keep the servicing costs down, as fllet buyers tend to sell before they are 5 years old so arent too worried about longevity past then.


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## trenchfoot (Jan 11, 2007)

Judas said:


> no helicopters have it done because if they crash - everyone dies.........:doublesho
> 
> gearboxes........the risk is a bit less.......!


Exactly my point - *not* changing the oil leads to wear/damage/failure


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## patmac (Apr 17, 2009)

tmagnet said:


> Shouldn't have been that many bits of metal in the plug unless you're a bit of a gear cruncher? Sure there wasn't something else wrong with it?
> As said before, I did a change on a 1960's g/box and the magnetic plug had very little metal attached to it...and i've heard the driver crunching the gears (and done it myself) plenty of times lol


Like i said, it was a mg zs. AKA rover 45. nuff said, its been replaced with a benz


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## biggriff (Feb 9, 2009)

I never allow gearboxes to just run and run with the same oil. Always change it at about 20k. Thats plenty for a modern gearbox.


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## perm (Oct 26, 2005)

Many thanks for all the advice....
As I intend to keep the car, will get the gear box oil changed at the next service.

Can not do any harm and may just give me a few more years of smooth gear changes.

Cheers


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