Hello,

I have a 1992 Ford Aerostar, 3.0 engine, A4ld trans, fluid very dirty...dirty trans....shifts wonderfully though. I have had the fluid changed 2 times, and the fluid is still very dirty. Recently replaced vacuum modulator and hose(s). I had the fluid changed after the modulator replacement, but, for some reason, fluid now leaks out of the trans onto the muffler pipe after driving in stop and go traffic after a while. Does this mean the trans is killing itself? It runs so well, and shifts so well..... I can't seem to keep the fluid clean though. I didn't actually do the fluid changes myself, but, paid a reputable mechanic to do it. Maybe they were changing all of the fluid? I am tired of paying 100+ dollars each time to get the trans cleaned out. This problem never started until after I replace the vacuum modulator. I have had the car for quite a while, with no other problems. The motor and trans have very low mileage....60k, but, the car body has about 165,000k miles on it. It there anything that I can try to do before having someone to go in and replace seals? I feel that the fluid is boilover, because it is so dirty. Can someone help, please! :-(

 

What you are calling dirty fluid is actually heat failed ATF fluid contaminated with tranny friction material from failed ATF fluid induced slippage. No outside dirt or combustion contamination is involved.
Time to clean tranny and change all the ATF, approx 10 qts.

1. Make sure the "mechanic" cleaned the tranny pan bottom of all grit and friction material dust when he changed the fluid.
Also, have mechanic adjust bands, 2 adjustments on outside of tranny.

2.Do complete gentle flush of all 10 qts, search this forum for gentle flush technique out thru tranny cooling return line.

3. Put in largest tranny cooler that will fit in front of radiator/AC condenser

4. Refill with high quality Mercon type ATF, Chevron Iso-Syn, Valvoline MaxLife

5. Add 10oz bottle of Lubeguard "red" ATF protectant and cleaner and bottle of Auto-RX if you can stand the price (search web), run 1000 miles

6. Do another complete 10 qt "gentle flush" and put in one of the Full Synthetic Mercon ATF's, Mobil 1 Mercon, Redline, Amsoil. Add 10oz of Lubeguard "Red"

7. DO NOT have a tranny shop "Power Flush" your tranny.

8. Do complete "gentle flush" every 30k>50k miles or when ATF darkens.

Would you run your engine 60,000 miles without completely changing the motor oil?

 

I noticed a point here that is very important. Never, never power flush a transmission. One of the most important things to do in this maintenance cycle is to change the filter. Jiffy lube power flush does not do this. Trans filters are on the suction side of the pump which is engineering heresy. Very easy to clog and when this happens, pump loses pressure, clutches slip and bands burn. Result, metal puree'. Power flushing is strictly prohibited as maintenance by all manufacturers.

 

Hi Cnajp:

It maybe leaking at the new modulator. Did you do it yourself or did you hire somebody to do it? Anyway, make sure the O-ring on the modulator is there, and make sure that it's clamped down tight with the forked clamp.

Other than that, all advices given by others are sound ones. I used to have the burnt fluid problem until I wised up and put in the biggest tranny cooler that will fit in front of the condenser. To heck with the A/C, tranny is more important

Also, this is how I flush my tranny. Go to a hardware store and buy a T the same size as the steel tranny line and a small ball valve, the same kind you put under the kitchen sink. Just locate the return line from the radiator, put the T in that line and the valve on the third branch of the T. Then you can run the engine, bleed one quart out of the return line and add one quart of clean fluid. After you spent about 20 quarts of clean fluid, you'll see great results

Regards

 

reason auto manuf.'s put primary auto tranny filter on intake to pump is that bands and clutch packs occassionally have friction material break off in chunks large enough to damage pump. One of these pieces goes thru an expensive close tolerance tranny pump and it's metal eating toast time.

Most aftermarket "filters" now are a large gap metal screen, 0.010" or more, which will pass lots of small grit and debris, including "Power Trashing Flush" hairballs and dirt from someone else's tranny.

Ford original factory filter in Aerostar 4R55E tranny was a filter media mat thicker than oil filter that filters out the manuf'ing fine metal cuttings and casting grit. Replacement Motorcraft is just the "filter the barndoor mentality" screen. Don't want to plug up the pump intake with the fine friction material that wears off in normal use from bands and clutch packs.

add an inline filter after the pump in the return cooling line

http://www.txchange.com/ptk.htm

 

I agree with the in line filter concept, some commercial trucks use them, I think that is great. It is interesting that Honda does not use a suction filter, there is just a drain plug and fill port on their trannys.

 

We all know that's why Honda transmissions are among the worst on the planet

 

mine never gave me any trouble....but it was a manual. it does make you wonder though.

 

Exactly, Honda makes great manual trannys, but they could never (or didn't bother to) design proper automatic trannies.

 

Yuppy women putting on their eye makeup while driving would never stand for a correctly designed Honda automatic for their wonderful high rpm DOHC 4 cyl.'s, with a 4000 rpm upshift point and no engine computer distortion of IVTec and engine timing at shift points to soften the shift. Automatic downshifts at 2000 rpm.
Honda auto tranny's kill themselves and the hi tech engine in front of them.

 

Did you know honda automatic transmissions are not planetary. they all are countershaft transmissions like manuals with clutches to engage each gear. Not a band or sun gear in sight.

ken1mod

 

Yes, that's my understanding. Honda's automatic transmissions aren't real automatic. They're essentially manuals.

 

Interesting, I dont guess it makes any difference, but they are very different inside, I wonder what advantages or dis advantages they have, heavier longer, etc. I do trust a clutch pack more than I trust a band. I have had 5 honda automatics 2 which I kept until 190000 miles or so, never a problem even with woman drivers. I still own 3. are you guys sure you are talking about hondas?

Ken1mod

 

Honda's auto tranny's have small clutch packs for hp and rpm input requirements. Honda tried to compensate with high coefficient friction material and a high friction proprietary ATF similar to the old Ford type F.
Wife has had 3 Honda products with auto tranny's including a Acura TL w V6 and 5 sp auto presently.
They have all shifted the same, neck jerkers and gear hunters on hills and in town slow speed driving. '02 Accord V6 had auto tranny fail at 45k, Honda covered under their customer retention program but what a paper work pain. Her CRV shifted like a drunken Samuri warrior chopping meat.

Honda has had a number of design flaws in their auto tranny's including gear lubrication and overheating/cooling, 6 qts is inadequate for cooling and lube in an auto tranny.

The Europeans have built outstanding automatics for small high rpm DOHC engines for years, take a look at Volvo, BMW and Mercedes.

 

I would think there wouldnt be much room for large clutch packs in the honda boxes, very interesting commentary. I had a 91 acura legend with 200 hp regularly raced friend with t-bird sc motor and regularly won. I never babied that car and enjoyed it until jerk ran into it from side and totaled it with 192000 miles. Isn't the crv that continuously variable trans? Those can be very strange to drive, they are a belt and pulley transmission like the nissan murano.

Ken1mod