Gearbox oil...

[Sandspider]

Hi guys

Firstly, Happy New Year! I hope you too are nursing hangovers.

And secondly, a gearbox oil question. My father got me some gearbox oil for Christmas (bless him!), but he appears to have got one litre each of two slightly different forms. Both are Castrol 80W90 grade, but one is EPX 80W90 (differential transmission fluid, API GL5) and the other is EP 80W90 (manual transmission fluid, API GL4). I have a vague thought that one of these may be for open gearboxes, and the other for sealed...?

Anyway, can I mix them and put them both in my Lux gearbox? Or I should I stick to one type or the other? (From looking on Clark's garage, it looks like both are suitable, but when mixed...?)

Thanks,

Giles

 

[Hilux]

Swepco or Redline are recommended for 944 transmissions by many.

GL4 rated oil is OEM spec its just that some oils to that rating and recommended by owners seem to quieten the box more.

GL4 and GL5 shouldnt be mixed and note also there is some evidence that GL5 attacks bronze synchro`s and (I believe) is designed for seperate diffs etc whereas GL4 is designed for manual gearboxes/diffs.

Someone will be along to agree or shoot me down in flames regarding some of the above but I`m positive GL4 is what you need.

 

[944 man]

Youll need more than two litres too. Some manuals incorrectly stated the gearbox oil capacity. IIRC its 2.5 litres, not 2 litres.

 

[Sandspider]

Thanks Paul.

What you say makes sense, and no disagreements so far! Looks like I need another litre or two of the GL4. Why do I always decide to do these things when it's sooo cold and grim outside? [&:]

 

[Hilux]

Also, always make sure the filler plug can be undone BEFORE you undo the drain plug.

 

[AntB]

ORIGINAL: Hilux

Also, always make sure the filler plug can be undone BEFORE you undo the drain plug.

So a good soak in plus gas the night before then

 

[zcacogp]

Drain plug and fill plug check is a good idea before you start ... although it wasn't a problem on mine.

I haven't used Swepco, but it is VERY expensive for what it is. I change the gear oil on mine with good quality stuff which costs about £3 a litre (if you know where to buy it from) and it works a treat. I reckon a change every 15k miles or so is about right. (Swepco costs about £40 a change, for comparison.)


Oli.

 

[Alexw]

I'm planning on doing this... when I can be bothered. I was talking to a fella at Hartech about the gearbox oil, he said many he has seen have what he assumed was the original oil in there [&:] and described my stuff as looking fine. God knows how they checked it though..... lickle dipstick?

 

[Copperman05]

ORIGINAL: zcacogp

Drain plug and fill plug check is a good idea before you start ... although it wasn't a problem on mine.

I haven't used Swepco, but it is VERY expensive for what it is. I change the gear oil on mine with good quality stuff which costs about £3 a litre (if you know where to buy it from) and it works a treat. I reckon a change every 15k miles or so is about right. (Swepco costs about £40 a change, for comparison.)


Oli.

£40 on a good quality synthetic gear oil isnt really that much to spend every 15k or so, especially when compared to how much one would spend on petrol over the same period (about £2,600?). Invest for the future I say.

Edd

 

[zcacogp]

Edd,

I am using good quality synthetic gear oil! Just not expensive branded stuff ...

Fair point about the cost being low given the frequency of change tho'.

AlexW - good Q. There is no dipstick built in. Perhaps they took the fill plug out (easy job when the car is jacked) and stuck a finger into the gearbox.


Oli.

 

[Sandspider]

Hi Scotty.

No! I just have difficulty changing from first to second and back again when the gearbox oil is cold - hence the need to change it.

Oli, are you getting the Vauxhall trade discount stuff?

Giles

 

[zcacogp]

ORIGINAL: Sandspider
Oli, are you getting the Vauxhall trade discount stuff?

Yes. I think it's Castrol (it comes in the same design of bottle as Castrol gearbox oil, but of a different colour and with a different label.)


Oli.

 

[barks944]

Recently changed my oil from newish (I think) swepco to some castrol or w/e from halfords to see if it cured a gearbox squeek, I didn't really notice any difference except the swepco was green and wierd. Kind of a waste of expensive oil I know but I guess it was worth a go to see if the squeek went away. It didn't cure the squeek, which I now think is TT no 4 bearing closest to the gearbox.

 

[AntB]

Had my gearbox oil changed at GT One in Cherstey a few months ago.. They used Mobil synth stuff - Pete (GT One guy) says its the best that they get for the 944's gearbox on quality v value for money.

With you Oli - regular changes with half decent stuff has to be the way forward (or reverse [])

 

[awattam]

ORIGINAL: sc0tty

It defo makes a difference to the gear shifts. I spent about a year driving my S2 before getting the gear oil changed, now my gear shift is superslick and most satisfying !

One strange thing I have noticed however is I do find the gear change a bit stiff if I have been on the motorway in 5th for a long time, and then come off the motorway and change down through the gears. Anyone else notice this?

I had this when I first got mine, it would take a bit of effort to get out of 5th gear after being on the motorway for a while (at least half an hour I would guess). A while since I studied g-box design but I believe this is down to 'cone jamming'. Anyway it was cured with a change of gearbox oil. The shift improved a lot too, especially when cold.

A hint if you can't get the gearbox filler out, I was able to fill mine (VERY slowly!) through the speedo drive. Adding the amount stated in the manual. Easier if you warm the oil so probably best not to do it this way at the moment.