Transmission oil change

[bossboy2]

(06-12-2018 )Rawze Wrote:  I use 75-90 or 80-90 in mine. Always have. Tranny has more than a million miles on it and still is tighter than most I have driven with half the miles.


there are many who disagree with this, claim lower fuel mil,eage and such. I have not seen lower fuel mileage on mine, maybe it is because I don't run 70+ mph. 50-wt makes them wear out much quicker.

Just my own opinion, no one has to agree.

Rawze, is this a synthetic that you are using? Or conventional?

[bossboy2]

(06-20-2018 )Nilao Wrote:  Funny thing is all other countries like Australia, Europe, Asia, India, etc alk specify 50w or 75w90/80w90 as approved viscocities. Only here in the land of the free are we restricted to one weight by the manufacturer.

:big_smile2::big_smile2::big_smile2::big_smile2:

[Shandro]

Anybody have experience running 75w90 in minus 30 or colder? Or will it be the same when cold range selector is a little stiff but will be fine after.

[Nilao]

That might be a bit extreme for 75w90....I'm not sure. Could be fine if you never shut the truck off as the heat off the engine would keep it warm enough to flow. But a cold start would probably require an extended warm up period.

[Shandro]

That's what I was thinking could take awhile. We try not to haul when it's that cold but when they phone and say you can bring grain in its hard not to say no. We usually haul when it -20 to -25 celsius not sure what that converts to Fahrenheit

[Chamberpains]

-25c is -13f. I've had no problem with mine at that temp. Just a little slow at start up. So ya, a little longer warm up to get the oil warmed up. I also flip all selctor switches multiple times after warm up, but before I attempt to move the truck. This gets the cold thick oil off of the synchronizers. They may grind a little is you skip this step. And it may not be the oil on the synchronizers as much as its frozen moisture in the air solenoid or selector donut being a little stiff and slow.