97 Grand Marquis 79K

I found a mechanic that works on Police cars here in Atlanta to chage my ATF fluid. I have searched the forums and other places and find conflicting info.

Mercon or Mercon V - I find arguments for both

Change filter or not change filter - ditto

So.... can someone who knows from doing it yourself or good solid advice suggest what I should do?

Joel

def get a new filter..and i think v is better and will work fine on your trans...dont forget to tell him if he doesnt no, to drain the tourqe converter if equipped

Where have you seen on this site not to use Mercon V?

USE MERCON V!

Just be sure that the guy's not going to use a trans flush machine - I've heard bad things aboot those machines blowing seals and whatnot. Look in the tech articles section on how it should be done, and ask if that's what he's going to do. Another good idea is to just do it yourself, to make sure it's done right.

Mercon V is better than Mercon, but I only use Amsoil ATF. A bit more expensive but it lasts twice as long as Mercon V.

As for the filter: would you change your engine oil without changing the filter?

I agree with Squeek... changing the filter is a must. I have no clue as to the fluid dynamic in the tranny, but if the dynamics change when there is less fluid than specs call for, I would hazard a guess that there is a chance of back washing the contaminants from the old filter into the new fluid until the fluid tranny is full if it is run at all. An old-timer transmission mechanic at Yellow Cab here says that a dirty filter is a killer.

Mercon V Mercon V Mercon V Mercon V Mercon V... nuff said

I use Amsoil ATF and have found it to last longer as well. Even in a taxi.

Change the Tranny pan gasket, tranny filter, drain the converter, and pour in 12 quarts of MECRON V!!!

The transmission mechanic at Yellow Cab never let one forget the importance of changing the filter... almost as important as the fluid he would say. If it gets clogged, or slows the flow, you cook the tranny in a heartbeat. He retired before we started running the new Fords... but he rebuilt them in various makes for 40 years. I change mine.

Mercon V... nuff said

I use Amsoil ATF and have found it to last longer as well. Even in a taxi.

I'm finally changing the fluid tomorrow. Should've done it 50k ago.

Please allow me to correct some slight errors.

1) The trans pan gaksket DOES NOT need ot be changed, and there is no reason to do so, if the factory steel impregnated rubber gasket is still in ok condition (not torn up). Using the cork POS gasket supplied with almost every filter kit is utterly worthless, and they WILL LEAK.

2) If the AT filter is so clogged that it NEEDS to be changed, well it is far too late for that now, and the trans is near death.

3) There is no point, or arguement FOR regular Mercon fluid in an AODE/4R70W trans. The ONLY fluid to use is Mercon V, period.

I would change over to M5 and do it yourself. There is a good procedure in the technical section and once you get started it is pretty easy to do. I drained my torque converter too. I don't think you need to use a machine, just drain the trans and TC, change the filter and put in new fluid.

I just did my 2005 P71. It was actually pretty easy once I figured it out and with the advice of GrandMarq9807 guiding me.

Part one- Dropping the pan and changing the filter.
Simply drop the pan using a combination of 3/8 and 10mm sockets with a 4 inch extension(preferably with a bit of a swivel head, I used Sear's Craftsman). You'll notice the front edge of the pan actually is partially covered by the lip of the cross member, this is where the swivel head extension is essential! Remove all the bolts except the two rear corners and one of the front corner bolts. Your pan will have begun leaking on the front corner that has no bolt, slowly remove the remaining front bolt allowing your fluid to drip into the catch pan. Eventually you'll be able to let that front edge of the rest on the top edge of the cross member. Now you can remove the two back corner bolts and carefully lower the pan. It still has a couple quarts in it. Pour that sucker out and clean the magnet (it pulls off the pan). Be amazed by how filthy it is! Now pull out the old filter and replace with a new filter (make sure the old filter gasket is gone). You should get a new pan gasket with your filter. Put the new gasket on and bolt the pan back on.

New Pan/U-Haul Pan
At this time I discovered my pan had rusted through and I thought I could pull it off with the original reusable gasket. It didn't. It leaked. So I ordered the infamous U-Haul transmission pan (F8UZ-7A195-AA) that features a drain plug!!! I called the local Ford dealer and told them I could get it online for $67 so they knocked it down to $83 from $99 and it arrived 3 days later. The parts dept. said there are only 11 remaining in the whole nation so get yours now.

Changing the transmission fluid

For pre 2003 cars you can go ahead and drain the Torque Converter through the little drain hole hidden behind plastic plug on the bell hosing. Drain and replace.

For 2003 and later cars, you have it easy! Add whatever number of quarts you drained from the pan down your fill tube/transmission dip stick hole. Use a funnel! Should be 4 or so. Now hopefully in advance you've bought 3-6ft of 5/16 clear plastic tubing as well as a double sided 5/16 male coupling (both sides male). Pop the hood and directly down between the belts and the radiator. You'll see two 5/16 plastic hoses connecting to two metal tubes. Disconnect the driver side tube and connect your clear plastic tubing to the black hose with the 5/16 coupling. Put the other end of the plastic tubing into a reservoir (I bought a clear 2 gallon water container that had quart hash marks for $2.50). Have someone turn the car on and let 2 or 3 quarts pump out. Shut it off and add whatever you pumped out. Turn it back on and while you are pumping out the next batch have them go though the gears. Do that once and then keep pumping out and replacing the fluid until you see the bright red of the new fluid or you have gone through all 14 quarts of MERCON V (at $5 a quart!) Do not use anything but Mercon V!!!!

Reconnect the hose and you are done! Your local auto parts store has a oil dump for your used fluid.

Thanks again to GrandMarq9807!

My car is a 2005 P71 with 75,000 miles and I was amazed at how dirty the fluid was. I really recommend this. I thought that because it was a cop car they would have serviced it but I found the yellow transmission plug in the pan so I know this was the first time. Stuff you will need: 14 quarts Mercon V, transmission filter and pan gasket, 3/8 and 10mm swivel sockets and 4 inch extension from Sears, drain pan and for the 2003+ cars 3-6ft 5/16 clear plastic tubing, 5/16 male to male coupling and a container that allows you to measure how much fluid is pumped out (like a gallon milk jug). And a funnel to pour the Mercon V down the dipstick tube.