I've seen posts on several of the Ranger forums cautioning not to put ATF in the manual transmission if someone mistakenly had used gear oil previously. This is not an issue with my truck, but I find it curious. What is the reasoning behind this? Why wouldn't you just drain the gear lube and replace with the proper fluid?

 

ATF is for Automatic trans nor a M/T
M/T take gear oil like 60 , 70, 80 wt
Kind of like a rear end take uasally 90wt

 

I understand the differences in the two fluids. The specifications on my '93 call for ATF to be used in the M/T. My question refers to posts where people have warned others that once gear oil has been incorrectly been put in the tranny, that they should not drain and fill with the proper fluid - ATF.

 

Bump, I have a bad trans leak in my 91' MT. I recently put in 75W 90 and just found out that I should be using ATF. Now that half of the fluid has all leaked out again, I am looking to refill my trans. Should I use the same gear oil I previously used or should I refill with the proper ATF? The shifts are terrible with the gear oil and the trans takes forever to warm up and then the shifts get better. I am in Chicago and its January, so its pretty damn cold here. Thanks guys.

 

Might wanna do some more research. Most manuals now use ATF. Mine does and even states in the manual. Some even use motor oil. As far as not using the other after one has been used has got me. I've never heard this before.

 

I'm using Royal Purple ATF/MTF fluid in my truck with no problems!

 

I don't see any reason to NOT switch back to ATF if gear oil has been used in the tranny. I would recommend that a drain & re-fill be performed several times after some miles to be sure all the gear oil is gone & not contaminating the new ATF.

 

other way is if its got a cast iron case it takes gear oil....
If it has a Allumimum case it takes atf.

 

Wrong.

If its a Mitzubishi tranny it takes gear oil. And the Mitzu's are cast aluminum. So if your Ranger is from 85-92, there is a good chance it has it.

All other manual Rangers had the M5OD. This takes ATF fluid, and always has.

 

Thanks for all your input. I've read several posts in the past stating, very vehemently, that once gear oil had been introduced that you couldn't go back. I didn't make any sense
to me then, and I haven't read anything here to change my mind.