The Automatic Transmission

It has been said that there are only two things in life that are certain; Death and taxes.  The undocumented third certainty is that Mazda 626's are NOTORIOUS for possessing bad automatic transmissions.

[ Click here for additional information on the inner-workings of an automatic transmission. ]

Due to a lack of proper heat dissipation as well as poor valve and solenoid design, the automatic transmissions on any 626 starting at 1992 and going all the way up to the 2001 models will fail.  It's not a matter of if but simply when.

The first time that the transmission died in my car was around 112500 miles.  (I was told that it's pretty good for an automatic transmission in a '93 to last that long)  I felt my blood run cold when the "HOLD" light started flashing slowly on my car's dashboard indicating that the computer had detected a failure.  One day in mid-April 2001 the car went from being drivable (I'd just completed a round trip to Chicago in the car two weeks prior) to being a very attractive but rather useless lump of metal on wheels.

I did not take it to the Mazda dealership to be fixed.  Over the phone they estimated that it would cost at least $3800 to replace the transmission.   I found that rather arrogant on their part given that the failure to properly design the transmission caused it to die in the first place.  Since the car was well out of warranty, I decided not to waste my time or cash with Pulliam-Wray Mazda (now known as Wray Automotive).

Instead I took it to a local mechanic who (I was told by someone I trust) had experience with 626 transmission rebuilds.  The repairman estimated that because it had only just started to fail the work wouldn't be that difficult.  He test drove it and agreed that it was probably the clutch plates and the torque converter that were dying.

All of those components (and the planetary gear set!) were replaced to the tune of $1400.  I asked him to add an aftermarket transmission cooling coil to help vent a lot of the excess heat that is generated by these transmissions under regular usage.  (At only $150 to $200 installed, this is a very smart investment!  ANYONE who has a 626 with an automatic should consider it a requirement of ownership to add that to your transmission.  Heat kills transmissions!)  Furthermore, a fully synthetic transmission fluid that is supposed to stand up better to heat was used.

Did I mention that this had been the *first* time the transmission died in the car?  Well I should've guessed that something was amiss with LD Walker's repair job when they gave me a six month-6000 mile warranty.  Despite the fancy-schmancy transmission fluid and the aftermarket cooler, the damned thing went out on me again on February 9, 2002 after only 11200 miles!

I was on the way to work on I-20 eastbound (on a Saturday for the state government! *gasp**shock*) and was attempting to pass a car when suddenly my engine roared mightily and the car started slowing down.  I immediately looked to my right and sure enough the "HOLD" light was flashing.  Swearing a blue streak, I coasted across three lanes of traffic (I was grateful that it was on a downhill grade) and came to a halt at the exit to where my office is located.

Trying to figure out how I was going to pay for it, I wavered between fixing the car or biting the bullet and getting another car and saying "to hell with this thing."  I test drove a couple of cars, including a 1999 626 LX with a stick.  First of all I was surprised at how much of a quality decline there was between the interior of the 1993 626 and the 1999 626.  Secondly I was not in a good bargaining position.  The used-car salesman (them again!) was a bit of a shark; trying to push me into a purchase regardless of what I wanted to do (almost as if he were the one spending my money instead of me).

Taking all of that into consideration (particularly the hellish debt I would incur on purchasing another vehicle)  I nixed the idea of purchasing another car and had mine taken to Mr. Transmission.  I was quite angry at having basically thrown away $1400 on a bad tranny repair job, so I asked the guys to let me see the transmission.  The folks at Mr.T agreed to let me inspect it and called me once the transmission was out of its housing and on their workbench.  I didn't know a whole lot about transmissions outside of the basic function of the parts inside, but I knew enough to understand just what had gone wrong with mine.

The torque converter, which had already been replaced once by LD Walker in the previous maintenance go-round, had disintegrated and rained metallic particles all over the transmission's inner-workings.  The two round magnets installed at the bottom of the transmission pan were coated with what looked like iron filings (it looked like a couple of metallic Chia Pets laying on the bottom of the pan).  The fluid pump as well as the hydraulics of the valve body were clogged with this metallic flotsam which had caused the mechanism to jam, giving me a stellar 0 MPH at 5500 RPM...  After seeing this mess I authorized the repair of the transmission and walked away in disgust.  They spent three days tinkering with it and fixed the following:

(quoting from the invoice: anyone who wants to help me clarify some of the terms please send me email!)

• Rebuilder Kit
  
• Transmission Fluid Filter
  
• Intermediate Band
  
• 8.5 quarts of transmission fluid
  
• Torque Converter "Da 30"
  
• Pump Update
  
• Thrust Washer Kit
  
• Solenoids
  
• Shop Supplies
  
• Front Mount
  

There is something that everyone needs to keep in mind regarding heat regulation in transmissions. The general cooling configuration for any vehicle that possesses an automatic transmission relies heavily on the engine's radiator. If you look carefully at the radiator you will likely notice two smaller hoses connecting to the radiator in addition to the two large rubber pipes that one expects to see.

Those smaller hoses are transmission fluid lines which run heated fluid from the tranny to coiled pipes within the radiator. The coiled pipes are submerged in the same antifreeze/water mixture that circulates through the engine core and serves to lower the engine's temperature. This gives you an idea of just how hot the insides of a transmission can get if boiling-hot engine coolant is capable of reducing the temperature of the tranny fluid.

Once the cooled transmission fluid finishes its circuit through the coils running through the engine's radiator it is returned to the tranny via the other small hose. So if the engine is experiencing overheating problems, those problems will also severely affect the transmission and could hasten the death of that component because the superheated hydraulic fluid is not being cooled sufficiently. This being the case it is a VERY good idea to heed the following:

• Regardless of where you live if you do not already have a transmission cooling coil on your vehicle then get one now. Don't argue, don't second guess and don't put it off. This item should not be considered an optional thing. What is a transmission cooling coil? It is simply a "mini-radiator" that is spliced onto one of the transmission cooling lines that head to/from the engine's radiator. Trust me, doing this now will only benefit you in the long run.
• Assuming that you've flushed and boiled out your engine's radiator and verified that the thermostat is in working order; in hotter climates where you might notice the engine's temp needle moving a bit you may want to consider having a larger or "heavy-duty" engine radiator installed to replace your standard one. This will not only protect your engine from overheating but will also assist your transmission in keeping its internal temperature within tolerable levels.
• Religiously adhere to a transmission fluid monitoring schedule. Be sure to change the fluid no later than every 18 months or 20000 miles or whenever you notice any discoloration of the fluid. As was mentioned earlier, transmission fluid is nothing more than hydraulic fluid and it works best when it hasn't been scorched or burned.
• This Transmission Fluid Maintenance Link will give you even more information as to the whys and wherefores of fluid and filter maintenance, along with a comparison of various transmission cooling methods and parts. Of course I recommend the higher-end coil with the fan, but that's just me. :)