Helpful Car Repair Tips

Tips to Save on Transmission Repairs

Posted by Brian Brown on March 9, 2010 at 10:46 AM

1- How do I check the transmission fluid level?

Always check the fluid level with the engine running (except Honda), the transmission in "park" (except Dodge products which should be in neutral with the emergency brake applied), and with the engine at operating temperature. Remove the dipstick and wipe with a rag. Insert the stick fully and remove. Look at both sides of the stick to verify the same indication. Repeat the process.

The reason to check both sides of the dipstick is that after the fluid circulates through the transmission, it dumps back into the pan area and will cause an agitation of the fluid. This creates an uneven level and some fluid will "slosh" onto the stick and give a false reading. Some transmissions are worse than others.

Note: If you check the fluid level after the engine has been off for a long time, fluid from the torque converter will drain back into the pan area where the level is measured and give you a false high reading. When the engine is started, the fluid in the pan area is used to fully charge the transmission and torque converter. Also, the difference of fluid temperature will affect the measurement. The fluid volume expands when heated to operating temperature.

Another method of checking the fluid is to turn off the engine and immediately check the level. This will stop the agitation and give an accurate level (no agitation) before the fluid in the torque converter has had a chance to drain back into the pan area which would give a false-high reading.

Tip: If you have added fluid, go through the same procedure, but repeat the process several times before you look for a reading. Some of the added fluid will adhere to the side of the filler tube and can give a false reading.

Tip: If the fluid level is low, you have a leak! Transmissions do not consume fluid. Have the leak diagnosed and repaired to prevent more serious problems.

After you have added fluid, drive the vehicle for a mile or two, then recheck the level. This is especially important in front wheel drive vehicles.



2- I have a leak. Can you tell me how much it will cost to repair it?

There are numerous places that a transmission can leak. They include: the pump, shift lever seal/s, kickdown seal, electrical connection/s, governor cover, speedometer, rear output seal or axle seals, servo cover/s, filler tube, throttle cable, pan, side cover, cooler lines, and differential cover.

The real question is: What is/are the source/s of the leak/s. Most people can only see the bottom of the unit, and therefore conclude that the bottom pan gasket is leaking when, in reality, the leak is from above and running down and around the pan. Therefore, it is imperative that the unit be visually inspected to evaluate the leak situation!

So, the answer to the question is: No, I can't without seeing the vehicle.



3- Can I drive with a transmission leak?

It depends on the rate of fluid loss. A minor or slow leak will allow you to drive as long as you maintain the level in the normal range. You will have to establish the rate of loss and replenish as necessary. It should be obvious that if fluid is running out as a stream, that you won't go very far. A transmission will usually operate "normal" until the fluid loss is a quart or more. Then the unit will exhibit abnormal operating symptoms and internal damage is occurring. What started as only a leak can result in a major repair bill if ignored!



4- Can you tell me how much it will cost to overhaul my transmission?

My first question back to you is: Which model transmission do you have and how do you know it needs to be overhauled? Occasionally, a poorly running engine, restricted exhaust, computer or sensor, poor electrical ground, or other problem not internal to the transmission will be the cause of abnormal operation. Tragically, I have had numerous vehicles brought into the shop having had major work done on the transmission itself or the unit replaced, but the operation problem is still present. This usually turns out that the problem was never in the transmission, therefore never resolved. What a waste!



5- How long does a transmission normally last?

The is no accurate answer to that question. The mileage or time of use before major problems occur will vary greatly, and therefore, I don't see a correlation between mileage and expected transmission failure. It is not unusual that the first few years after a newly designed transmission hits the road, that early failures occur. But, in later years with updates to the original design, the units become more reliable.

The three major factors in the life expectancy are periodic maintenance, maintaining proper fluid level, and driving habits.



6- How can I make my transmission last longer?

Just like the dentist tells you, "Don't ignore them." Check the fluid level and condition periodically, repair any leaks/problems promptly, service the unit on a regular basis, and add an auxiliary cooler if the vehicle is used for towing, commercial, or high ambient temperature climates. Some units should have a shift kit installed.

Synthetic fluid may benefit some applications by lowering operating temperature resulting in a longer life, but not all transmissions can use the synthetic fluid.. Check with your local ATRA shop for their advice to your specific application and needs.


7- What is a "shift kit?"

The kit is an aftermarket service pack that has been researched and developed to compensate for design deficiencies discovered in a particular transmission. In most cases, the kit improves the quality of shifts, increases the internal pressure that operates the unit, and provides better lubrication.

Note: Not all transmissions need the kit.


8- Will it hurt to overfill the transmission?

In a word, no! Although, it is possible that gross overfilling can cause the fluid to be subjected to moving parts and become aerated which could cause abnormal operation. You may also notice leaks that ordinarily would not occur.


9- Will overfilling "blow" seals?

In a word, no! The transmission case is vented preventing pressure buildup in normally un-pressurized areas. Severe overfilling can raise the fluid level such that the transmission may lose fluid through the vent or leak from seals that are above the normal fluid level, but the fact remains that the seals that are under pressure and those that are not will not change because of the fluid level.

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