i have a modifed 1985 4x4. The trans has bin upgraded before but after an oil filter change and the addition of some new oil the trans dose not shift as well as when it was filled with only B&M shifting oil.

The good guys at NAPA told me to try a tractor oil reated at 10 wight for my C/6 trans it cost 15 bucks a gallon much less then the B&M stuff.

Should I try the tractor trans oil or just get the B&M again?

Also how much oil will i need if I have the transmission oil flushed out ?

 

I could be wrong on this but I believe that older ford trannies had to have a friction modifer in them. So if the other fluid you bought did not then that is why the difference in shifting. b and m makes some really good stuff and if you have much money in that trans I personally would go back to b and m fluid.

 

Well to be honest I was leaning that way, Its just that the owner of my local NAPA was soo sure. I wanted to run it by the forum.

Ya I have put some money in the transmission, but the tendency is to push it as far as you can.

I will ask my local shop how much oil to buy for the flush.

BTW, nice truck.

 

I believe the C6 uses type F transmission fluid, the mercron/dextron is not interchangeable with type F.