what type of fluid should be used in my b2s trans. Its a 5 spd. stanard. When I drained it it had GEAR OIL, and a friend with the same trans. told me, that I should use ATF. Which is it????

 

It's in chapter one of your Haynes manual. 1983-1987 takes 80 weight gear oil. I've been using 80-90 Amsoil synthetic in mine since it was new. I think thats why my trans is still going strong with 221K miles on it.

 

I changed mine 2 weeks ago and put 80 weight oil per the Haynes Manual.
Draining the oil was not a problem, but getting fresh oil into the unit was interesting. After laying there under the little beast for a while wondering how to get oil from the gallon jug to the fill plug, I got the idea to use one of the oil bottles with the pointed cap that I had left over from a previous project and my air compressor. I ended up jamming some clear tubing over the pointed end of the cap on the bottle, and making a hole in the bottom of it. I inserted a basketball needle into the hole and turned the regulator on my air compressor all the way down (10 psi or so) and ran the other end of the tube through the fill plug. Then I pressurized the bottle which made the oil flow into the tranny. It wasn't messy and it didn't take long to fill the tranny. My only concern was blowing up the bottle with oil in it, but that didn't happen. I am not sure if the plastic bottle would have stood up to more the 10 psi I put into it, so if you try this, please be careful.

 

The mitsubishi transmission (FM145, FM146) will take 80-90 gear lube. The Mazda transmission (M5OD) will take ATF. An '87 BII would have the Mitsubishi transmission from the factory. Is it possible someone has replaced it with the Mazda tranny?

 

For 88 thru 91 Haynes shows that the Mitsubishi trans uses 80 weight gear oil & Mazda uses Mercon ATF. 009Bronco the Ford spec in your owners manual should be ESP-M2C83-C. which is 80 weight gear oil. My 87 Ranger has a Toyo-Kogyo 5 speed & the owners manual & Haynes both show Ford spec ESP-M2C83-C. Russ, great idea with the compressed air, i'll have to remember that little trick.