[MetroMPG]

Looks like the gearbox may have had the wrong weight oil in it! I just "fixed" it by replacing the oil with a lighter weight mixture.


Back story:


I knew when I got the car that shifting gears was a little problematic -- 2nd gear was occasionally reluctant and/or crunchy. I figured that was the price for buying a car that the previous owner admitted was her first stickshift.


But with fall temperatures getting closer to freezing, resistance shifting into 2nd gear (and sometimes 1st and 3rd) became a real problem. Double & triple-clutching didn't solve it, either.


Molasses:

When I opened the drain plug, almost no oil came out. (Ambient temp around 5C / 40 F.) For a moment I thought it might actually be empty! I had to remove the fill plug to get it to drain properly.


Comparison to factory spec oil weight:

The car calls for 75w-80, but the lightest my local parts store had was Redline synthetic 75w-85. I took a chance and bought some.

Then just for fun I compared the viscosity of the new & old oils by timing how long it took to drain half a litre of each through a container with a smal hole poked in the bottom.

I also tested some 5w20 synthetic motor oil for reference.

Time to drain 0.5L @ 5 C ... Oil type



2 min 25 sec ... old gear oil

1 min 22 sec ... Redline MT-85 synthetic gear oil 75w-85

1 min 13 sec ... 5w20 synthetic motor oil


Shifting problems fixed!

I mixed together the synth 75w-85 with some lighter Royal Purple "Synchromax" MT oil and re-filled it.

What a difference! The car is a pleasure to shift now. (Well, as much as a Mirage can be.)

It looks like someone may have put the wrong oil in it. It was manageable in the summer, but would have been almost undriveable in winter temps. Makes me wonder if the shifting problems contributed to the previous owner getting rid of it. She said it was only ever serviced at her local Mitsu dealership, too.