Frequently Asked Questions Quality Transmission Service, Tempe, Ariz

25- My older vehicle's transmission shifts into reverse ok, but has a delay going into drive when cold.

This symptom is very common in 3 speed rear wheel drive Ford transmissions that are several years (8 years +) old with high mileage (100,000 +), but can happen with any make.  The symptom is caused by heat traveling from the torque converter through the input shaft to the forward clutch drum.  The o-rings, particularly the inner, that seal the forward drum piston in the forward drum become hardened over time and mileage.  They loose their ability to seal properly, so when the fluid pressure is applied to the drum, the piston doesn't move to apply the clutches.

The delayed engagement starts at several seconds and progresses to several minutes.  If the inner o-ring breaks, there will be a sudden increase in the delay.  After the transmission comes up to operating temperature, it works well until it sets long enough for the symptom to occur.  The C-4, C-6, and FMX transmissions are the units that will usually exhibit this symptom, but can happen in others.  Front wheel drive and overdrive units rarely exhibit this symptom.

If the delay becomes intolerable, the cure is to overhaul the unit.  I do not recommend using an additive that will "soften" the seals.  This may help in the short run, but cause other major problems in the long run.  A transmission with the accumulation of miles and time for this symptom to occur will undoubtedly has significant wear in other areas.

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26- My vehicle needs some expensive repair.  Should I have it repaired or replace it?

There are several questions that you will need to answer:
    Does the vehicle still meet your needs?
    Do you like the vehicle?
    What is the cost to replace the vehicle?  New or used?
    How many car payments does the repair cost equal?
    Can you expect the vehicle to last throughout that time period?
    If the replacement vehicle is used, what repairs will it likely need?

You know the history of your vehicle.  The used replacement vehicle's history may not be as clear.

If you're planning to buy a new vehicle, the sales tax and tags cost may cover the cost of repair of your present vehicle.  These two expenses are not "buying" anything with respect to the actual vehicle.

Certainly, I can't estimate the pride of ownership of a new vehicle, but that choice is usually the most expensive option to resolve a repair problem!  Additionally, it is virtually impossible to predict the future repair problems that your vehicle may need, but if you have established a good relationship with a repair facility, they should be able to provide some sage advice to help with your decision.  If not, you're on your own.

Personally, I drive a 1972 Chevrolet pickup that I bought in 1976, so I believe in keeping a vehicle that I like and meets my needs.  In 1999, I replaced the motor at a cost of $3400.  Was it worth it?  Certainly I think so.  I'm still driving it.

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27- Should I have the transmission "flushed" or serviced conventionally?

The total transmission flush involves hooking up a special unit to the cooler lines of a transmission and doing a complete exchange of fluid.  The good news is that you can replace virtually all of the old fluid with new.  The bad news is that occasionally there will be some material that is disturbed and contaminates the valve body.  Also, the filter is not changed because the pan is not removed, nor are you able to "read" any wear material residue that has accumulated in the bottom of the pan.

Personally, I'm not a fan of the flush.  I still believe that a conventional transmission service is the way to go.  Drop the pan, change the filter, replace the pan, and fill with fluid.  Done properly, you should not have a leaking pan gasket.

The only time I would consider the flush is when someone is converting from conventional transmission to synthetic which is good for transmissions that are used under severe conditions such as commercial use, heavy loads, or towing.

There's another method for changing the fluid called "suck and fill."  With this method, the fluid is sucked out the filler tube then new fluid is used to refill the transmission.  The major problems with this technique is that the filter is not changed and there is no way to see any material collected in the pan.  However, if you are changing the fluid frequently (at 10,000 to 15,000 mile intervals), you could use this method every other time.

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28- My transmission will not upshift for the first few miles when it's cold.

The usual cause for the symptom is hardened internal rubber lip seals on servos or clutch drum pistons.  With the transmission is cold, the lip seals stick in their "at rest" positions.  When fluid pressure is first applied, they will not move for awhile, but when they finally do they will function until the transmission cools down and the process is repeated.  Additives that are formulated to soften internal seals will usually do more harm than good for the transmission in the long run.  There is no way to control the affect that additives have on the seals, and therefore, the repair of the problem is to overhaul the transmission.  The degree of "hardness" of the various seals in a transmission will vary greatly.  The seals that are not hard will be softened to a gummy, swollen mush.

When the transmission reaches operating temperature, the seals are softened enough to function properly.  Invariably, this problem will get worse with age and colder temperatures.

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29- I have a noise or vibration.  Where is the source?

Noises and vibrations can be two of the most challenging problems to resolve.  It is imperative that the cause be determined before repairs are attempted.  Often, parts are replaced in hopes of curing the symptoms, but there is no change.  This can get expensive, as well as exasperating!

When it is suspected that the transmission is the source, the real cause can be drive line, engine, or exhaust related.  Also when the vehicle is in gear, bad engine/transmission mounts can contribute due to the torque on the engine during acceleration.  The torque will occur in one direction in forward and the other way in reverse.  As a result, you can experience a vibration in forward or reverse and not the other.

A common technique for diagnosing the source of a drive-train related noise is the have the vehicle raised on a lift with someone in the driver's seat and another technician underneath the vehicle.  The driver can "drive" the vehicle in an attempt to duplicate the symptom or noise while the other technician can locate the source.

Before a repair is authorized, ask if this is a guess or a fix.  If it's a guess, whose money are we gambling with, the shop's or mine?

Also, it is necessary that you be involved in the diagnosis.  Never leave your vehicle at a repair facility with the expectation that the technician will be able to determine the correct symptoms and repair.  This rarely results in a satisfactory resolve.  The vehicle owner needs to point out the specific symptom and what circumstances are necessary to duplicate the problem.  You need to be involved in the diagnosis!

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