mixing ATF's as benign as mixing oils?

[Titan]

Pan drop on an 04 Grand Marquis with 39000 miles, specs Mercon V. Only gets out 4 quarts out of 12-14. No problem with adding Mobil 1 Mercon V synthetic, is there? Did a test-run down the highway, couldn't tell any difference. I plan on extracting, replacing 3-4 quarts every 7500-10000 miles. That should be fine for a highway driven car that I'll drive about 60000 miles a year, isn't it? Probably change the filter at about 100,000 miles.

 

[blakegeo]

I don't know if your transmission torque converter has the rubber plug, like my '97 Town Car. If it does, you can pull it and with a screw driver rotate the converter just under the housing to the left until you find the drain plug. Rmmove it with the male end of a 3/8" socket extension and drain about 6 more qts.

 

[CharBaby]

If your Grand Marquis calls for Mercon V, then Mobil 1 Mercon V is an excellent replacement.

 

[ConfederateTyrant]

No harm will come of mixing those two. Unfortunately, as blakegeo was mentioning, Ford quit putting drain plugs on the torque converter in 2000 (if I recall correctly).

 

[Donald]

I would say you should do 1 or 2 more drain & refills now then go on your program of a drain & refill at 7500-10000 miles. Your tranny still contains much of the old ATF with 39K miles on it and you want the majority of it out as its used up and contains wear metals.

 

[Titan]

Thanks everyone. They did away with the converter drain plug a few models ago, so, when I bought the car in mid-October, I had the local Ford dealership flush/exchange the fluid. That was at 29,400 miles. I've driven 10,000 the past two months, and coinciding with my oil change, I dropped the pan. Interesting thing about these transmissions is there is a plastic plug with an o-ring that is rolling around free in the bottom of the pan...that's how you can tell the pan has never been dropped. They use the plug in the fill tube, and it gets pushed into the pan during installation. It can freak you out if you aren't expecting it. Also, they have a BIG round magnet in the pan. I was surprised at how clean everything was. I think I'll just extract and refill every oil change for the next several. Probably drop the pan once a year (that's 50-60K miles for me) to clean it. Hopefully my 75 mph highway cruising and this schedule will allow the transmission to make it past 200,000 miles. I know the engine will do that with no problem.

 

[ConfederateTyrant]

Quote:
Interesting thing about these transmissions is there is a plastic plug with an o-ring that is rolling around free in the bottom of the pan...that's how you can tell the pan has never been dropped. They use the plug in the fill tube, and it gets pushed into the pan during installation. It can freak you out if you aren't expecting it.

A friend of mine was scared the first time he dropped the pan on a Grand Marquis and saw it. Then his boss told him "well, you popped its cherry." Apparently those plugs were called cherries. Funny mechanic humor, got to love it.

 

[dwendt44]

Highway driving, with the converter locked up is the easist on the T fluid. You can certainly go longer with your drain intervals if you wish. Yearly?
Many mfgs say the T-fluid is 'lifetime'; suggesting 100K life.
I go 35K on T-fuild and it comes out looking good even then.

 

[RF Overlord]

Quote:
Apparently those plugs were called cherries.
I've also heard them called "lollipops" and "baby-rattles".

...and yes, I was freaked out the first time I saw the one in the pan of my '94 T-bird...on a Sunday...thought I was doomed.

Titan, your plan sounds excellent and is very close to the way I maintain my Marauders. Mercon V is not a fluid but a specification, so any ATF meeting it should be compatible with any other.

 

[Titan]

I'm feeling really good about my plan; thanks for everyone's help.

 

[Donald]

consider a Magnefine filter.

 

[Titan]

Nope, not in these transmissions. Any extra filter decreases flow. Ford recommends an external filter only for a short time, and only if a rebuild was done. In fact, the OEM filter is considered "lifetime" for normal use. Just 30K flushes...

 

[SWHeat]

Originally Posted By: Titan
Nope, not in these transmissions. Any extra filter decreases flow.


Awww, cummon now. You can't give such a blanket statement like that and expect to get away with it. Ford can recommend what they want, but an external filter will NOT "decrease flow."

What next, you can't add an external cooler either...cause it will "decrease flow?" Let's be reasonable now.

 

[bmwtechguy]

Can anyone else comment on the idea of an additional filter on these transmissions? I always thought that extra filtration was a good idea since the regular filter is on the suction side of the pump and is mostly a glorified pickup screen to protect the pump and keep larger stuff out of circulation. I think the safest way to guard against decreased flow through the cooler is to do a timed test filling a quart or gallon container of fluid from the exit side of the inline filter, compared with flow time at same location before adding the filter. If it takes significantly longer to fill, then your filter is too restrictive, possibly. Time to consult with Gary Allan and get some advice on what to do...

 

[Titan]

Originally Posted By: SWHeat
Originally Posted By: Titan
Nope, not in these transmissions. Any extra filter decreases flow.


Awww, cummon now. You can't give such a blanket statement like that and expect to get away with it. Ford can recommend what they want, but an external filter will NOT "decrease flow."

What next, you can't add an external cooler either...cause it will "decrease flow?" Let's be reasonable now.

I am NOT an expert, I'm only repeating what the person crowned "Expert" says on Crownvic.net. These dudes do things like: drill a 0.93 hole in a number 10 pinhole in some sort of transmission fluid flow disperser to make the car get into reverse more quickly. This Expert is the one that is continually correcting the notion that adding a filter to these transmissions is good...he shows the FORD technical bulletins that state extra external filtration is only recommended after a rebuild when contamination is suspected, and the external filter should only be used a short period of time, then REMOVED...for the reasons I stated related to decreased flow.

I don't know if he's smoking something, or if he knows what he's talking about. However, I believe him based upon the questions he's always answering, the detail of the pictures he puts up, his ability to help so many people with advice that works (even when a shop couldn't figure out the problem).

I'll put no external filter on mine based upon this Expert's recommendation.

 

[SWHeat]

Titan, as far as the specifics of your particular transmission....go with the expert by all means.

I just had a quip with the blanket statement "any filter decreases flow." I guess if you get down to minutia you are correct. In practical application, I think not.

Yours tranny is the first I've EVER heard of external filtration being a bad thing.

 

[Titan]

He could be wrong. But, I'm in no position to refute him. And, I agree with you that blanket statements (like mine) are often wrong!

 

[ConfederateTyrant]

While this may only be true for the idling situation, but when idling, it takes almost a minute for 1 gallon of ATF to pump out in my warm transmission. Filters should manage way more than that per minute. Some of the hydraulic filters that Gary suggests are in the 20-30 gallons per minute flow rate.

However, maybe during the driving there is a much greater flow rate, but I'm not sure on that.

 

[firemediceric]

I just put the Magnefine packaged for Ford on the return line of my F-350. Good idea or is flow restriction a concern?

 

[Gary Allan]

Magnefine is an OEM part number for the Ford transmissions. A $$$ part under the Ford label. You see them on ebay every once and a while.