Technical Gearbox oil change

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Technical Gearbox oil change

murphyv310

No Fiat now unfortunately
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Hi.
Well I was about to do an oil change in my 1.2 Panda's gearbox. First thing I did was to loosen the filler plug, then remove the drain plug that doesn't exist!!!!!
I don't have a suction pump so the change was shelved in the meantime.
I did though remove the level plug and nothing came out I struggled to actually dip the tip of my finger in and get some oil on it. So I have topped it up and for any to drip out it took 450ml. So this looks like an under fill from the factory. Since topping up I went for a run and there is definitely less gearbox whine and down changes seem an awful lot smoother, will need to wait and see what it's like cold as on occasions I've had to double de clutch to do a down shift.
 
APOLOGIES
I put the car on the ramps this time and found the drain plug :eek:
So I have since drained off the oil and refilled (on level ground), not been for a run yet as I'm having a cuppa.
The oil was really quite dirty looking and one or two little bits of metal came out too. No doubt the low level was hard on the oil, hopefully I have caught this in time for no lasting damage. :)
 
Hi.
Interestingly prior to buying new oil I read the handbook and under lubricants it stated "Tutela Transmission Gearforce" on looking up this oil it states it is a GL4 of SAE75 classification, fully synthetic. Reading a few threads it seems that GL5 is recommended. TBH I have bought a GL4 75W-80 fully synthetic to exactly the same spec as the Petronas Tutela oil.
Having never opened up a Fiat box nor is there any info as to the materials used in the synchro cones so I have no idea if a GL5 oil would be more harmful in that case.
I remember the gearbox in my 2001 1.2 Doblo MPV had a dreadful leak when I got it (turned out to be driveshaft inner gaiter) and I was topping it up every two days before I was able to do the repair, in that box I used 10W-40 semi synth cheap engine oil and the box was a delight, quiet and smooth and that was approaching 130,000 miles!!
 
I think the use of GL4 or 5 relates to whatever metals are used in the 'box and what sort of load on it.

I think 5 is rated for extreme pressure and has a much higher copper content to account for the load.
I think the trans in my old Rav4 AWD took GL5 but the 2wd took 4.

Gear oil can start to go black due to the Sulfur and Phosphorous that is added to coat the gears and protect them, when they start to get hot, it almost cooks the stuff.

If you strip a 'box down, you often notice the oil can be quite clean that spills out, yet the oil clinging in between the teeth is dark grey or black.
 
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