Motor oil vs gear oil..(sorta)

[kafka45]

Ok.. I've got an 89 Dodge Dakota 3.9L with a manual trans. I'm gonna change fluid and the manual says 10 30 motor oil. Was just wondering in 33yrs if anything better has come along. I think it has Redline MTL 75w80 in it now (from the 5 year old receipt I found in the glove box).
thanks.......

 

[GR_CoB]

Redline MTL is good stuff, I like Redline MT90 though. My manual spec's MTL, but I used MT90 instead and never looked back. Improved shifting compared to original fluid (Honda MTF, which is comparable to Redline MTL) and more linear performance when running through the gears in the middle of summer (aka spirited driving). Original fluid made the transmission a little more audible as fluid warmed up, MT90 kept it smooth and quiet from freezing cold to scorching hot.

 

[MolaKule]

Ok.. I've got an 89 Dodge Dakota 3.9L with a manual trans. I'm gonna change fluid and the manual says 10 30 motor oil. Was just wondering in 33yrs if anything better has come along. I think it has Redline MTL 75w80 in it now (from the 5 year old receipt I found in the glove box).
thanks.......

Most MT's of that era used a 10 cSt MTF. A 5W30 falls into the 10 cSt range:

Redline MTL 75W80
Amsoil MTF (9.7 cSt)
GM and AC/Delco Synchromesh’s
Volvo MTF 645
Fuchs TITAN SINTOFLUID SAE 75W-80 synthetic MTF (Carries a GL-5 rating as well)
Lodexol (Morris Lubricants) MTF
Motylgear 75W-80

For a well worn MT the next higher viscosity MTF would be a 12.0cSt@100C and SAE 75W85 such as Redline's MTL-85.

 

[BMW Dom]

Just stick with the Redline MTL 75w-80