My Manual transmission is making a whining noise, i know i need to add oil to it but what do i add? someone told me i can add motor oil to it but others have told be 80-90w gear oil.

any suggestions?

92 Dodge shadow Es

 

Straight 30 weight motor oil. Or, 10w30 motor oil. The FSM (Factory Service Manual) likely lists which the factory was using at the time. Dodge has a bad habit to change between their ATF and their own MTF in early years, but basically, most MTF's are a 30 weight motor oil. Multi-viscosity may shift better on cold days at start-up, but should be replaced much more often!

 

80-90w gear oil

 

Alldata lists 5w30 for a 2.2 or 2.5L 4 cylinder.
The 3.0L Mitsu is not listing the fluid type. Which would be about right for a Mitsu

 

And researching a Caravan with the Mitsu 3.0L Manual Trans, it uses 5w30 also....
Put 80-90 in it, and you'll kill it!
And, given the warmer climate in this area, the 10w30 would generally hold up better. 5w30 is also recommended for the motor, but only in a climate where it will see temps below 0 Farenheit....