Factory manuals and transgression service manuals list the recommended service intervals of the transmission at an average of 30,000 miles. 

Be sure to check the OE requirement for each transmission for the exact mileage. In severe duty,  the intervals of changes will be shortened. 

Be sure to use the proper transmission fluid and additives as recommended by the OEM vehicle manufacturer. 

Transmission fluid is a multi-application fluid. It lubricates, is a coolant, and is a hydraulic fluid operation the transmission. 

Dirty fluid and filters cause a drop in the fluid circulation rates, causing more heat build-up, which causes the transmission fluid to deteriorate and oxidize, which causes the burnt smell and becomes very sticky. This condition creates excessive wear. 

Excessive heat is the number one cause for transmission failure. 

A restriction in the flow of the transmission fluid can result in major heat build-up and transmission damage.

The restriction affects the hydraulic pressure, resulting in slippage leading to accelerated wear on clutches, bands, or other internal components.

Keeping the transmission system clean is very important. Removing any contamination that can interfere with the operation of transmission components, such as valve bodies and solenoids, will promote a longer transmission life.

by Mike Souza (ATRA Memeber)
Gears Magazine December 2011

Once upon a time, when a car came in with a transmission problem, there was a really good chance there was something wrong with the transmission. Batteries? Tires? Tailgates? Those were someone else's problems... they certainly had nothing to do with the transmission operation. 

These days? Well, weird things happen every day. Like transmission problems caused by low voltage, poor cable connections, or loose or dirty grounds. And to make things even weirder, the battery may still start the engine without being jumped or the terminals cleaned. 

So how do you deal with transmission problems caused by the battery? Start by cleaning and tightening the battery terminal ends before chasing electrical codes. Even if the terminals look good and the vehicle starts without a problem. And if it looks like this one (Right, below for mobile readers) don't even think of going any further until you clean the terminals and check the voltage. This particular instance was a 41TE where a shop worked on it for two days for solenoid codes.        

Here are five examples of cars with battery problems that affected transmission operation:

1. A Saturn equipped with a TAAT transmission had a complaint of hard shifts. There were no codes stored in any module. The battery voltage was low, but the engine started without any problems Charging the battery corrected the hard shifts. 
2. 2004 Saturn Vue with the MDRA Honda-type 5-speed transmission had a slip or delay on forward engagement. It sometimes fell out of gear at stop or defaulted to second-gear starts. The wrench light on the dash would light sometimes, but there were no codes present. Checking the battery revealed it would develop only 11.9 volts; replacing the battery fixed the transmission problem.
3. Dodge or Chrysler vehicles cycle in and out of lockup or 4th gear without any codes stored. This symptom appears most often at light throttle, between 35 to 45 miles per hour. There's a list of 22 or more issues that can cause this complaint, but the most common is loos or dirty battery terminals and poor ground connections. 
4. Ford trucks equipped with a power takeoff (PTO) unit ; the PTO stops working after a transmission rebuild. There's no problem with the battery voltage or connections; the problem was cause when the battery was disconnected during repair, causing the computer to lose its memories. TO correct it, you'll need to drive the vehicle for at least 7 miles at speeds over 50 MPH for the computer to relearn PTO function. 
5. Late model Mercedes vehicles with a weak battery or a replacement battery that won't provide adequate current for the starter. This can cause pump bushing failure because of the additional starter draw through the transmission bell housing. 

And the weirdness doesn't end with the battery: Weird things can happen to the transmission because of tire problems, too. Problems such as low pressure, wrong size, or mismatched brands can cause a range of "transmission" problems. 


For example: A BMW equipped with either a 4L30E, or ZF 4- or 5-Speed transmission won't upshift to or past 4th gear after driving on the highway. The transmission receives commands to only 3rd or 4th gear, with no codes stored. 
This particular vehicle had only 42,000 miles, and the right front tire was just changed because it went flat. The spare was new and had no mileage on it. The difference in tire size caused the computer to think the vehicle was in a high speed turn. The curve recognition software would downshift the vehicle to a lower gear and wouldn't allow the transmission to upshift past that gear. This is a safety feature to prevent the driver from losing control of the vehicle on high speed turns. The quick check for this problem was to swap the tire from the right front to the right rear. 
There' a list a mile long of all the issues tires can cause on 4-wheel drive vehicles. The most common complaints are clunks noises, and binding on turns, to name just a few. Use a stagger gauge to check each tire's size when working on these vehicles. An alternate check would be to mark each tire at the bottom with chalk, then roll the car straight until each tire makes 10 revolutions. All 4 tire marks must be within 1/4" of one another. This method might not yet yield accurate results, as even a slight variation in wheel direction can affect the tire position.

Another quick test: If you have a sand or dirt road nearby, drive off the pavement and onto the sand or dirt road. if you notice a sudden jump in rotation, you're probably dealing with a tire size or pressure problem.

Probably some of the weirdest conditions can be caused by problems with the vehicle's lights. And these conditions can be the most difficult to diagnose.

For example: Some early model Ford trucks may develop harsh shifts; at the same time, the odometer stops working. These vehicles are quipped with a programmable speedodometer/odometer module (PSOM) located inside the instrument cluster. No need to connect the scan tool to this vehicle: just look up at the dome light If it isn't working , the fuse for the PSOM may be blown. A short in the interior lights can cause a circuit problem.

Another problem with Ford trucks can occur with the taillights If someone replaced the original, incandescent, factory-style bulbs with light emitting diode (LED) bulbs, the PCM will think the brakes are being applied. The torque converter will cycle in and out at 25 to 30 percent throttle opening. The same conditions will occur if the cab-mounted brake light is blown, or changed to an LED bulb.  


Hyundai vehicles equipped with an F4A40 or 50-series transmission may stop moving forward when the backup lights are on. A Short in the taillight circuit can back feed into the reverse light range sensor circuit. The TCM is programmed to failsafe to neutral when a signal of reverse and drive occur at the same time. On this vehicle there were no codes stored in any module, and the problem wasn't identified until the transmission was replaced with another unit.

So you have these weird transmission problems that people spend days on, only to find that they're something simple... and completely unrelated to the transmission. Knowing this, maybe you'll remember to check more than just the fluid level.

Here's a set of basic checks that should help you isolate some of the weird problems:

• Fluid level
• Battery voltage (12.4V minimum)
• Battery ground
• Battery cables and terminal ends
• Body grounds
• Interior light function
• Exterior light function
• Instrument cluster gauge function
• Instrument cluster warning lamp function
• Diagnostic trouble codes stored in all modules
• Range/inhibitor switch function (check for start in each detent)
• Any aftermarket accessories installed (interior or exterior)
• Manufacturer and any aftermarket technical bulletins or recalls

And with that, you'll have a leg up on discovering those weird problems...before the have you chasing ghosts.

Slipping is one of the most common clutch problems. Slipping can occur right after installation or after years of service. A clutch slipping condition on a manual transmission equipped vehicle will manifest itself as excessive RPMs in the engine, but lack of acceleration.

Listed below are diagnoses of some different reasons for slipping:

• Contaminated friction material can contribute to a slipping condition caused by the loss of the material's coefficient of friction. 

Common causes of contamination include: over-lubricated input shaft splines, leaking engine rear main seals, and transmission input shaft seals. Inspect friction material for contamination. 

• If a vehicle has a hydraulic or manual cable release system, it is important to inspect for a binding condition. A release cable may be worn, stretched, or kinked. 

If you are working with a hydraulic release system, there may be issues with the slave cylinder internally. These can include deteriorated seals, o-rings, and hose. The master cylinder may also have a blocked compensation port. This would cause the clutch to remain partially disengaged. These examples can also cause unsmooth pedal travel. Be sure to properly inspect and test the release system on the vehicle.

• Another reason for slipping is improper step and cup dimensions after a flywheel has been machined. This would cause a "thick disc condition." A thick disc condition is a flywheel step that is too tall, or a flywheel cup that is too shallow. Due to the characteristics of the diaphragm spring the clamp load will be diminished, leading to a slipping condition. 

Remember to pay attention to OE flywheel specifications.  

Transmission Service Procedure- Remove the fluid from your vehicles unit, remove the transmission pan, replace transmission filter and filter seal (if unit has one), inspect and make any necessary adjustments (throttle pressure or band adjustments where applicable depending on which unit you have), replace pan gasket (unless unit has a reusable pan gasket), re-install transmission pan, and refill unit with fluid.

Transmission Flush-  A transmission flush (aka. drain and refill) is the service done when your unit does not have a pan or serviceable filter. Example: A Honda, or other vehicle manufacturers using CVT's (Continuous Variable Transmission). Instead, the unit has a plug located on the bottom designed for draining fluid. Service a CVT requires removal of the plug to drain the fluid, reinstalling the plug, and then refilling the unit with new transmission fluid to its proper level.  

When should I have a transmission service done? 
A transmission service is much like having the oil changed in your engine. The service needs to be done according to the service index table for your particular vehicle. Cloquet Automotive suggests having a service done approximately every 50,000 miles. If you have a heavy-duty or severe-duty vehicle we recommend having a service done every 30,000 miles. 

Why should I have a transmission service done? 
Having your transmission serviced regularly according to manufacturing service tables will help to keep your transmission running longer. It also reduces the risk of having future transmission problems and/or failures. Following your service maintenance table for your specific vehicle is important, but it is not a guarantee you will not have an internal transmission failure.

Transmission Fluid Exchange- A quality transmission fluid exchange is designed to circulate through and replace virtually all existing fluid with new by removing one of the transmission cooler lines and running the transmission cooling system through an external machine with a built in filter. This machine is designed solely for the purpose of draining the current fluid in your unit and replacing the old fluid with new fluid. Cloquet Automotive does not offer this service.

Why would I need to do a fluid exchange?
A unit where the fluid becomes contaminated would require a fluid exchange service. A few examples; it floods and your vehicle becomes submerged in water, or the wrong transmission fluid was added to your transmission.

Your car's transmission is the most complicated and least understood major component in your car or truck. In today’s cars, the transmission is a combination of sophisticated hydraulics and computer-controlled electronic components.

No one component in your car has more going on inside than your automatic transmission.

The transmission is a mechanical component designed to transmit power from a vehicle’s engine to the drive axle, which makes the wheels drive the vehicle.

By varying the gear ratio, the transmission alters the levels of power and speed to the wheels. For example, in low ranges, the transmission provides more power and less speed; in high ranges, just the opposite is true. This reduces the load on the engine, while increasing the vehicle’s speed and fuel economy.

Some vehicles use a clutch to connect and disconnect the transmission to the engine, controlled through a foot pedal next to the brake pedal. These vehicles have a manualtransmission. If your car doesn’t have a clutch pedal, it has an automatic transmission.

If you have to press a clutch pedal and shift the transmission manually, your car has a manual transmission.

Automatic transmissions depend on a special fluid — called ATF — to cool and lubricate the moving parts inside. But the fluid does more than that: In fact, it’s no exaggeration to say that the fluid actually drives the vehicle. So there’s little doubt that the fluid is very important to the transmission’s operation. This is why it’s important to check the transmission fluid level and condition regularly (check your owner's manual) and to have your transmission serviced at least every couple years.

Later model front wheel drive cars also incorporate another major component into the body of the transmission itself: the differential or final drive. These types of transmissions are known as transaxles.

Many cars today have the final drive incorporated in the transmission, to create a transaxle.

Front wheel drive configuration improves fuel economy and handling, and reduces manufacturing costs. But because of the additional components in the transaxle, it’s generally more expensive to repair than a transmission when it fails.

-ATRA
Articles, Automotive 101

I know none of us want to think about winter conditions, yet, but there are a few conditions that are common to most of the US and Canada during the winter months that are approaching quickly. How you deal with those conditions can have a dramatic effect on your transmission.

Cold Temperatures — When living in Minnesota, winter means cold weather. As the temperatures drop over the next few months, your vehicles fluid will begin to thicken, thus reducing their ability to lubricate. In most cases, you can deal with this simply by driving slowly and cautiously for the first few miles, until your engine and transmission reach normal operating temperature.

Remote car starters are a great invention of the last few years, and they definitely make your car less chilly when first getting in, but try to avoid letting your car idle for extended periods of time. Sure, the passenger compartment will be nice and toasty by the time you get ready to go, but meanwhile your engine will be running rich, creating additional pollution, damaging your catalytic converter, and using expensive fuel to go nowhere.

Also, for many transmissions, you may be damaging the internal components as the engine idles. That’s because some transmissions don’t create lube flow with your shifter in the park position. Oil does not start flowing through the cooler and lube circuits until you physically move the shifter into drive. In other words, internal transmission components are spinning — ice cold — with no lube flow. Not good.

As Minnesotans we know it tends to get really cold in our area. It might be a good idea to invest in an engine heater that plugs into a wall outlet and warms the engine before you come out in the morning. A timer will allow you to start the engine warming a few hours before you’re ready to leave, saving you money, and your car wear.

Snow and Ice — Driving on snow and ice is part of a normal winter for us here in Minnesota, but there are specific hazards to your transmission onour roadways that you need to know about.

One that you may not be familiar with is what can happen if you get stuck. Too often, drivers spin their wheels, in the hopes of freeing themselves from a snow drift or icy patch. This can cause major damage to the transmission; here’s how:

Today’s cars use a computer to control transmission operation. When you spin the wheels, the computer sees the vehicle speed rising; in many cases it has no way of knowing that you aren’t really moving. When the speedometer registers 40-or-so MPH, the computer sees the speed, and identifies driving conditions as being right to engage the converter clutch. Now the engine is locked directly to the drive wheels. If the wheels regain traction, their speed will drop suddenly. The result can be catastrophic to the transmission.

The best way to get out of a drift or icy patch is to rock the car back and forth… forward and reverse… until you can get moving again. Or, better yet, get someone to push or pull you out of the snow. Avoid spinning the wheels, or you could end up damaging the transmission.

Water in the Transmission — No major component of your car can survive indefinitely with water in its internal components. But no other component can be damaged as quickly as your transmission can by water. 

Even a small amount of water in an automatic transmission almost always results in serious failure and major repair bills. The reason is the band and clutch linings are hygroscopic; that is, they absorb water, even if they have to push transmission fluid out of the linings to do it.

This water quickly finds its way down to the metal backings, causing them to rust and lift the linings off of the clutches and bands. The result is metal-to-metal contact, which always means serious damage to the transmission.

To avoid this type of trouble, steer clear of deep puddles. Should you find your car submerged, don’t start the engine. Your only chance of avoiding a big repair bill is to have your car towed into a transmission shop and have all the oil drained out immediately.

If you're lucky, draining and servicing the transmission may be all that’s necessary to save it. If not, your auto insurance may cover part or all of the damage.

There's a  lot you can learn about the condition of your transmission just by examining the fluid. Today, many manufacturers have begun to stray from the traditional red color. Transmission fluids may be green, yellow, some may even have a bluish tint. But in virtually every case, clean fluid will look clean and smell clean. So checking the fluid’s color and giving it a little sniff is a great indication of whether your transmission is in good shape, or in need of service.

Here are the basic conditions you are looking for:

Of course, fluid condition isn’t the only thing technicians check when examining a transmission’s condition. They also look at operating condition, computer system codes, and any loose material in the pan, to name just a few. Oil condition is just one of a series of clues they use to diagnose transmission condition.

If you’re unsure of whether your transmission fluid indicates a problem, stop by Cloquet Automotive at 1310 18th street Cloquet, MN, 55720 or call us at 218-879-1974.  We would be happy to help you out.

Remember when the THM 700R4, now more commonly know as the 4L60/E, transmission was introduced in the early eighties.  The  700 transmission drove the industry crazy with broken pump vane rings, burned 2-4 bands, premature 3-4 clutch failure, sprag failures, planet failures, etc. I'm sure you remember the first few high performance transmissions? During the mid to late eighties, many performance and durability products had been developed so that the 700 could be successfully repaired in average vehicles as well as for high performance street strip vehicles. 

I will discuss some of the principal areas for high performance modifications. Although there will be discussion on hydraulic controls, the various high performance, after market valve body kits, work very well whether it's for furnishing very short and firm tire chirping shifts in an IROC-Z , or ferocious shifts in a drag strip 11.52 et runner. Valve body kits offer convenience, since most are packaged with parts and data to modify main line pressure, shift scheduling, shift feel and firmness, detent downshifts etc. The parts and technical information also coordinate with the separator plate orifice sizes, 2-4 servo pistons, accumulators etc. For all installations, we suggest that you follow the instructions carefully. Write down every step that you perform. This way, if a calibration change is needed, you will at least have a reference point. 

Okay, let's build this 700 to be a winner! You, the transmission, and whomever the customer is will be a winner too!

This servo piston technical information has been around for years but since it's really important for high performance usage, let's quickly review it. Look at the casting number stamped into the second servo piston. There are three different size second servo pistons identified by the last three digits of the casting number which are 553, 554, and 093.  Corvettes came with the 093 piston. For short, firm, but fairly comfortable shifts for street  use start off with the 553 piston. For street and strip use or for big blocks and high-rev small blocks, or for tire chirping shifts to show off, use the Corvette 093 piston. For brutal, tire peeling shifts, a billet servo setup is available, however, use this setup with caution: The maximum throttle 1-2 shift will be really firm which can cause the sun shell to fail from overload. Never use the 554 piston in a performance application: You can burn up the 2-4 band over the weekend.

Located in the valve body, there are six known different size accumulator valves used in the 700. There is a letter code stamped into the end of the valve bushing. Letter codes A and N will provide the firmest shift while letter M provides excellent overall operation in passenger vehicles, trucks, and some low geared sports cars. Letters K, F, B should not be used in performance or heavy duty applications. Once you have chosen the right accumulator valve for your application, you are going to need the spring specifications. For the A and N valves, begin with a two pound, six ounce, spring at ta reference height of .073". For code M, start with a three pound spring at the same reference height. These specifications will help you to coordinate with the accumulator piston trim spring(s), second orifice feed, and the servo piston you're installing.

Most valve body kits will contain a heavier tension spring for the pressure regulator valve, to increase pressure. For the boost systems, begin by checking the size of the intermediate boost valve  by measuring the long, smaller land. If it measures below .297", you very likely will not achieve a short, firm, tire chirping manual 1-2 shift. The . 297 inch valve and bushing is available from GM or your parts distributor under part number 8648959. Now check the land opposite the stem end of the TV boost valve. Don't use a size less than .422 inch. The .433 inch valve is suitable for street and strip cars, trucks, Vettes, and IROC's. For big blocks or highly modified small blocks, use the .471 inch boost valve. The .422 inch boost valve and bushing is available under part number 8634941, the .471 inch setup is 9634940.

IMPORTANT TECH NOTE: On most high-rev applications, an upshift to second can occur even though the selector is in manual one. Installing the #8648959 .297 inch setup will keep the unit in first with the selector in manual one right up to floating the valves, however, at moderately higher speed, the unit will go into first if the selector is pulled into manual one after an upshift to second or third gear.

Be careful and thoughtfull here. Given the right road conditions, this can cause loss of vehicle control. Be sure to caution your customer! Having him or her sign a waiver or disclaimer ont he repair order might be a good idea. Installing a heavier pressure regulator valve spring only and ignoring these two boost systems could lead to sup standard performacne and many hours of rework so why not Fix It Right The First Time!

High performance, heavy duty and even light duty 700's have been known to experience premature 3-4 clutch failure or distress. This durability concern can be easily and effectively prevented by utilizing several options after confirming that the pressure rise control system is functioning properly. Check it with a gauge!

One option is to install standard thickness high capacity or high energy friction plates readily available from your parts distributor. These friction plates use use a special composition of friction paper for heavy duty and performance applications. Another option is to install thinner friction and steel plates-which are available through the aftermarket-allowing you to install as many as eight or nine friction's. When the eight or nine friction pack applies, the energy of the apply is distributed over more surface area therefore the clutch pack is able to hold much more torque load as opposed to the original capacity. In addition to increasing the torque holding power it also adds much more resiliency and an accumulative value to the clutch pack.

With an eight or nine friction pack installed, you can increase the third feed orifice to as much as .180 inch without experiencing a cut loose-providing that the pressure rise control system and everything else in the unit is functioning properly. If the third feed is between .093 inch - .110 inch and you desire additional high throttle firmness, remove the 2-4 servo assembly, and replace the original band release spring with a stock THM 400 intermediate band spring number 8623489.

When using the eight or nine clutch pack, we suggest using the red friction plates with either the dull or Kolene steel plates. If you purchase these plates separately instead of in kit form, ask your distributor for the four page instruction sheet which contains valuable technical information as well as stack-up procedures.

When building this unit for really heavy duty or high performance application, we suggest installing the heavy duty low-reverse planet with the deflector shield and matching output gear support. Always replace the sprag assembly on any 700 that has over 30,00 miles on it. using medium grit emery paper, hand sand the input sprag races. This unit needs a near perfect pump to maintain enough pressure and volume at high revs. your parts distributor can furnish you a high-rev pump ring kit with priming spring that reduces high-rev slide flutter and can handle up to 8,000 rpm. There are also relined 2-4 bands available with the red high performance paper. With this band, on manual high throttle 1-2 you'll spin the tires for sure! Finally, if the unit doesn't shift at the right time and/or doesn't shift firm enough, check and confirm that the main line pressure rise system is functioning properly before you start changing springs, servos, orifice sized and so on. If you don't check pressure rise...you'll be on a witch hunt for many hours. Fix It Right The First Time, so you and the transmission can both be winners!   

Numbers and Measurements from ATRA's
-GEARS Magazine May 1997 

Did you just spend a lot of money for a new transmission? Perhaps you know someone who did? Whatever the case may be you’d like to avoid major transmission repairs in the future, whether they are for your vehicle, or not. This makes sense because transmission repairs are expensive and no one is a fan of spending money these days -- especially for car repair. The most common cause of automatic transmission failure is heat. You can get more miles out of your transmission by reducing the heat that builds up during normal operation. As a transmission rebuild/repair shop for over thirty years now, we know a thing or two about transmissions, and would like to fill you in on a number of things you can do to keep your vehicle's transmission working properly for years to come. Some involve service maintenance; others involve changing your driving habits.  


Here are a few things you can do to help reduce heat, and keep your transmission working longer:

Service

1.  Check the Transmission Fluid Regularly.
Few things will reduce transmission operation and longevity more than low or damaged fluid. If your car has a transmission dipstick, you should check the transmission fluid level and condition at least once a month.

2.  Have the Transmission Serviced Regularly.
Regular fluid and filter changes can add years onto your transmission’s life. In fact, it’s probably the most cost effective maintenance procedure available.

3.  Add an External Filter in the Cooler Line.
While the filter inside the transmission usually does a good job of removing dirt and particles from the fluid, an extra filter in the cooler line is a great way to make sure of removing all the abrasive particles that can damage your car’s transmission.

4.  Check the Air Pressure in Your Tires.
Believe it or not, low tire pressure can rob you of miles from your gas tank, your tires, and the rest of your car...especially the transmission. The extra load caused by low tire pressure can seriously shorten your transmission’s life. Check the tire pressures at least once a month, and keep them filled to the factory recommendation found on the tire wall of your tires.

Driving

1.  Avoid Jackrabbit Starts.
Hard acceleration creates a lot of friction and heat in the transmission. Take it easy on the gas, and your transmission will live longer.

2.  Help the Shift.
Most of the friction and wear in the transmission takes place during the shifts. Get to know when your transmission shifts normally. Then, just before the shift, back off on the gas just a bit. That’ll reduce the load on the clutches, and eliminate much of the friction during the shift.

3.  Keep the Cooling System in Good Shape.
Your car’s radiator also provides cooling for your transmission. Heat damage will take place in the transmission long before the engine appears to overheat. Regular cooling system service can help your transmission run cooler and last longer.

4.  Add a Transmission Cooler.
If you travel a lot in extremely high temperatures or carry a lot of weight in your car or truck, an auxiliary transmission cooler is a great way to reduce heat and add years to your transmission’s life.