I am going to change the fluid in my 95 F150 tranny, it has the M5OD. With a little over 86K on the clock will switching to synthetic be asking for leaks or will I be ok? I was hoping to go synthetic to work better in low temps and keep wear to a minimum.

 

Synthetic Mercon III should work fine.

 

No need to worry about leaks?

 

The only leak problem with M5OD is the rubber plugs in the shift rails. I would change them. You could have a seal leak but I wouldn't blame synthetic oil for it.

 

Alright, that is what I thought. Thanks, if it ever warms up any I will do that on Monday.