HOW TO: Changing 5MT Gear Oil (Manual Transmission)

[davidricardo86]

I'm at 106k miles and I'm planning on changing the manual tranny oil. I took ownership of my Mirage at 75k and never changed it, i think I'm due.

I decided to try out this $14.97 Triax Gear Max MT 75W-80 GL-4, Full Synthetic Manual Transmission and Gear Box oil.






What intrigued me about this oil is it's claimed 500k mile service interval. I'd be happy with 250k with the number of miles I'm putting on my delivery Mirage.

Triax Performance Highlights:

• Exceptional frictional stability, even in off-road severe service.
  
• Long drain service up to 3 times that of most other gear oils, up to 500,000 for passenger cars, SUVs and trucks.

I consider my deliveries to be a "severe service" on my Mirage. I want something that'll hold up.

Two quarts shipped to my house came out to $33.16. I like that the oil is Made in the USA and the company is based out of Dallas, Texas. I'm still missing a funnel but otherwise i wanted to try out something different besides the tried and true Red Line MTL. I'm sure either oil is fine regardless.

I'll be sure to report back.

Edit 10/28/2021: changing the MT oil is such a messy job, what a PITA. When you remove the drain nut the oil comes out very fast and with pressure. My advice, use a large oil pan and be ready to move it quickly.

Edit 11/05/2021: i haven't had any hard shifts like i used to. At times i would grind between shifts. Not sure if it's a placebo effect or I'm just shifting better but it's been noticably less difficult.

[MetroMPG]

Draining

When you remove the drain plug, have a full-size drain pan in place! The transmission fluid will come shooting out of the drain hole several inches just like when you are changing your oil. For some reason I was expecting it to come out more slowly like heavy gear oil. As a result, it looks like the Exxon Valdez ran aground on my garage floor. Unless you are doing this job when it's really cold, the fluid is not thick.

No shooting in my case! Point of reference: 5C / 41F ambient temp & cold drivetrain.

The trans oil in mine drained out SO slowly when I removed only the drain bolt, for a moment I was afraid the transmission was empty!

I had to remove the fill bolt for it to drain properly.

NO danger of oil shooting anywhere at this temperature.

Unfortunately, I don't know what weight of oil was in there. The previous owner said it was only ever serviced at Mitsubishi, but I don't have the full maintenance records. So I don't know if this is factory oil or not.

[Top_Fuel]

The trans oil in mine drained out SO slowly when I removed only the drain bolt, for a moment I was afraid the transmission was empty...

Interesting! I'm sure it was 80+F when I changed mine. But 41F isn't that cold?!? I still would have expected it to drain quickly at that temp.

So how's your special trans fluid mix working out? Have you had a chance to drive it yet?

[inuvik]

No shooting in my case! Point of reference: 5C / 41F ambient temp & cold drivetrain.

The trans oil in mine drained out SO slowly when I removed only the drain bolt, for a moment I was afraid the transmission was empty!

I had to remove the fill bolt for it to drain properly.

NO danger of oil shooting anywhere at this temperature.

Unfortunately, I don't know what weight of oil was in there. The previous owner said it was only ever serviced at Mitsubishi, but I don't have the full maintenance records. So I don't know if this is factory oil or not.

Makes you wonder from the way you described it that somebody put some old school 90w-120 in it.

[MetroMPG]

^ That's along the lines of what foama thinks too.

[Mark]

Two quarts shipped to my house came out to $33.16. I like that the oil is Made in the USA and the company is based out of Dallas, Texas. I'm still missing a funnel but otherwise i wanted to try out something different besides the tried and true Red Line MTL. I'm sure either oil is fine regardless.

You can make your own funnel with the right size hose, but I found this cheap one at Auto Zone that also works perfectly for this job.

https://www.autozone.com/shop-and-ga...nel/557785_0_0

[davidricardo86]

No shooting in my case! Point of reference: 5C / 41F ambient temp & cold drivetrain.

The trans oil in mine drained out SO slowly when I removed only the drain bolt, for a moment I was afraid the transmission was empty!

I had to remove the fill bolt for it to drain properly.

NO danger of oil shooting anywhere at this temperature.

Unfortunately, I don't know what weight of oil was in there. The previous owner said it was only ever serviced at Mitsubishi, but I don't have the full maintenance records. So I don't know if this is factory oil or not.

How is your oil mix coming along?

When i removed my fill plug and then drain plug, the MT oil shot out of there like a racehorse! I LOL'd at TOP_FUEL's Exxon Valdez oil spill joke! The oil was definitely not thick, it was very runny and watery-like. Could've just been old.

In my opinion you probably should've warmed up the engine and transmission. Take it for a spin and bring the oils up to temperature. That way when you drain the trans the oil flows out of it more fluidly, less viscous. When oil cools it's viscosity increases. You want to get as much of that old oil out of there, warm it up and let the good times flow!

[MetroMPG]

How is your oil mix coming along?

Perfect! It's a different (much better) car to drive now.

Thread: Gearbox had the wrong oil in it? 5MT shifting problems fixed with thinner oil.

[Christopher_B]

Does anyone know the thread size for the manual transmission drain and fill plugs? I'd like to pick up a couple of magnetic plugs when I change the trans fluid in the next week or so.

[Christopher_B]

The fill plug is M18-1.50.