Thus the ATX fluid change interval should instead be 1yr/12,000 miles.
A Synthetic ATX fluid is available and withstands higher temperatures,
but in view of the abrasive material contamination in ATX gearboxes it
is better to use a non-synthetic oil annually than be forced through
expense to leave a synthetic oil in for two years: clean oil is best.
Clean oil can also markedly improve shifting & fuel economy.
-- Avoid Incomplete ATX fluid changes
Complete oil changes as per the procedure above are DIYable, with a cost of
30$US versus 2500$US for a gearbox repair they should be considered mandatory.
-- Inline ATX Oil Filter
The CD4E transmission has a filter, but it is embedded deep inside the
transmission for some reason known only to Ford. Thus it is very
advisable to buy an external inline oil filter (eg, www.permacool.com)
and do a complete fluid change annually. The transmissions are rated
only slightly above the US AXOD Taurus transmissions, and so the use
of cheapest-brand full-synthetic annually may be advisable since some
problems are as much design as overheating related.
o Stage-2 - Improve Thermal Cooling
o Oil Cooler Upgrade Choice
-- B) Hayden "Sandwich-Plate" Cooler
An alternative brand is B&M Automatic Transmission SuperCooler.
-- C) Setrab, Mocal, Earl "Sandwich-Plate" Cooler
The solution is an oil-cooler with Fan & Thermstat, so making the maintenance
of cooled ATX independent of vehicle speed even in stop & go traffic.
-- Smaller Mocal 115mm x 16-row Sandwich-Plate Cooler - 46.82
The cost-benefit is simple: 95.92 versus 1,800.00.
-- A UK Supplier of Oil Coolers is www.thinkauto.co.uk.
o Oil Cooler Comparative Sizing:
o Cooler mounting bracket
Last Upload: 16th February, 2002. V1.50a
Automatic (ATX) Gearbox Critical Maintenance
Primary Cause of ATX failure
o Insufficiently frequent ATX oil changes & overheating
are the primary causes of automatic gearbox failure.
o ATX oil (ATF) should run at 175oF, every 20oF above that
halves its lifetime - coolant temperatures quarter its lifetime.
The gearbox oil is continually contaminated by the circulation
of clutch-pack abrasive particles throughout the gearbox.
o Factory change intervals (600hrs) are too long compared to
the high temperature service life (300hrs) of ATX oil.
o In slow moving traffic there is little or no airflow
over the tiny factory cooler, and at the same time the
thermal input into the ATX oil will be at it's greatest
through normal torque-convertor slippage. At a minimum
the factory should have implemented a slightly larger
cooler with it's own temperature switched fan.
o The CD4E is a poor transmission, the 4EAT/GF4A-EL is a better
transmission (fitted to V6s) but both have overheating problems.
Solutions
o Stage-1 - Improve Contaminant Removal
-- Annual ATX fluid changes
The factory specified interval of 2yrs/24,000 miles is too long.
An average speed of 40mph for 24,000 miles requires 600 hours of running,
yet ATX gearbox fluid will degrade in GM THOT tests under 300 hours.
Changing the oil on an ATX involves dropping the ATX oil pan and replacing the
mesh filter. Unfortunately this only changes 3.8L of oil with 5L of dirty oil and
abrasive particles still remaining in the torque-convertor & gearbox.
To change all 8.8L of oil requires the following procedure: two large 20L buckets,
one with 10L of oil, the other empty; hoses to the ATX oil cooler are removed and
extended into the empty bucket; the engine is started for 1 second and the
hose ejecting oil is left in the empty bucket whilst the now identified
oil-intake hose is moved to the bucket containing fresh oil; the engine is
restarted and run until only clean oil exits. Two people are required and
Dealers do not perform such a service as routine - it must requested. Complete
oil changes will greatly extend the life of the ATX.
The mesh filter on the 4EAT ATX oil pan filters only to 200 microns. Inline
ATX-specific filters can be fitted which filter down to 50-10 microns
and so remove abrasive clutch material as it occurs rather than
circulating it around torque-convertor, clutches, valve-body, oil pump.
Traditional "spin-on filters" & adapters are available.
-- ATX fluid is used for lubrication, hydraulics (1,910 psi), cooling and actual
transfer of power to wheels. With power transmission losses of 20% and 120kW
available from the engine, up to 24kW largely in the form of heat must be
removed by the ATX fluid & a tiny factory ATX cooler.
-- When ATX fluid is overheated or "burnt" it degrades to a brown colour
and loses lubrication capability causing rapid transmission wear. Such
breakdown of ATX oil through overheating can be sudden, is non-reversible
and not readily obvious until catastrophic failure results.
-- A) Hayden "Tube-&-Fin" Cooler
Avoid. The several pipe & U-bend tube-&-fin motorhome coolers offer inferior
cooling in slow moving traffic, lower fluid flow. They are an old technology
compared to even the stock factory oil-cooler. A tube-&-fin cooler must be
much larger than the equivalent sandwich-plate cooler which has the disadvantage
of reducing airflow through condenser & engine radiator hence factory radiators
are of the sandwich plate design: greater cooling in a smaller package.
Appropriate. Brand names Hayden Trucool/Rapidcool. Near factory-grade cooler
providing high efficient cooling in a small package to maintain airflow
through condenser & coolant radiator.
---- Hayden 7134711, 8" x 11", 3/8"-NPT inlet, cooler, 60$US
----
www.bakerprecision.com/trucool.htm
Ideal. Whilst costing more, they are the factory grade solution chosen by
marque the world over for their reliability, efficiency & compact size
both in production & racing-team use.
---- Setrab # 616-6, 16-row, 4.75" x 13", 6AN fitting, cooler, 101$US
---- Setrab # 619-6, 19-row, 5.75" x 13", 6AN fitting, cooler, 115$US
----
www.bakerprecision.com/setrab.htm
-- D) Setrab, Mocal, Earl "Sandwich-Plate" Cooler with Fan & Thermostat
The real solution. The problem with all coolers is that they requires air
to be flowing over the radiator. Crawling along for an hour in summer heat
produces least air flow over the radiator when most is needed.
-- Fan housing for 115mm x 16-row - 20.05
-- Fan 119mm square, 12V - 22.05
-- Electric fan thermostat - 7.00
Costing little more than an oil change service, comparable to the
many junk automative "improvement" products out there, and also goes
a long way to negating the need for 8.8L of costly Synthetic ATX fluid.
-- To underline the undersizing of the stock ATX cooler, the Ford
1.8-engine uses a 24" x 4" ATX cooler, whereas the Mazda 2.5-engine
ATX cooler is approximately 70% smaller yet must handle a nearly 50%
bigger engine with 60% greater torque & thermal dissipation, and an
ATX which is known to have overheating problems in itself.
-- The compact sizing of the sandwich-plate design can be seen.
Following this sizing the Mazda unit should be 12" x 10" in sandwich-plate,
or an enormous 28" x 12" in the inefficient tube-&-fin design. Fitting a
tube-&-fin cooler will reduce the cooling performance of the engine
radiator & air-conditioning condenser.
Cooler Installation
o Hose clamps
-- Minaba hose clamps should be used on oil lines, particularly
where maintenance for complete oil changes requires their removal &
re-use. Minaba clamps use a double-band rolled-edge construction, no sharp
band tails; never leak, clamp all around the hose without cutting it;
re-usable. Stainless steel version are available.
Situate the ATX cooler in front of the coolant radiator to ensure low
temperature air in slow moving traffic. Where a cooler is not mounted
by pass-through plastic tags, it may be more ideally mounted to an
aluminium L-angle from a hardware store or
www.aircraftspruce.com. Aircraft Spruce offer 12"-multiple lengths
of 2"x2"x1/8" 03-48400 at 2.20$US, 03-48500 1/4" at 3.60$US, T6061T6 aluminium.
Mazda Factory-Remanufactured Automatic (ATX) Gearbox
Mazda Factory-Remanufactured Automatic (ATX) Gearbox
A factory remanufactured unit is available from discount Mazda Dealers
such as www.trussvillemazda.com.
Trussville are ~2500$US with old unit as "core". Their benefit is that
factory parts such as new cases are used if the original is out of spec,
and the considerable design improvements from 1993-2000 are implemented.
If sourcing a gearbox from elsewhere, ensure all updates are performed
so you gain the (greater) reliability of the 2000 gearbox and enquire
whether updated parts are available (stronger torque-convertor & Raybestos
Blue clutches for example). Annual oil changes should be effected on
any Probe/Mazda automatic gearbox as their cost vs repair is minimal.
Upgraded Automatic Gearbox Parts
URL: http://homepage.ntlworld.com/dorothy.bradbury/probemx/p_m20.htm