I'm surprised that no matches show up on a "C5" search on this site. Aren't there any C5 trannies out here? I have an '84 F150 302 with a 3 speed Auto (no OD). Searches elsewhere convinced me I have a C5 transmission. I just replaced the modulator which was leaking fluid. The dipstick says to use type "H" fluid and the users manual states type H for a C5 only (also confirmation of a C5). I never heard of it (and neither has AutoZone) and I can't find it anywhere. Some mustang sites with C5's say to use Mercon or Mercon V as a replacement for H. I added some "Multi" type fluid with the leaking modulator and the shifting is a little rough now. I don't think I'm starting in 1st as I get only one shift and often it feels like it goes from 2nd to 1st for an instant (racing the engine) and jerks into 3rd. Using the column shifter, all gears work fine. I hope I have the right modulator, there's no adjustment on it and I do have vacuum on the port. I have only 76K on the vehicle. I want to change the tranny fluid but I want to be sure Mercon is OK in place of the type "H". Also could use some tips on the fluid change. Some sites explain that dropping the pan only removes 1/2 of the fluid as much remains in the tranny and Torque Converter. Thanks! - Norm in Dallas

 

https://www.ford-trucks.com/forums/1...id-change.html Click on this link for a good writeup on changing the fluid. You can use a Mercron spec fluid.

 

Thanks, Lazy K!