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Frequently Asked Questions

        GOEREND FLEX PLATE:

       GOEREND VALVE BODY:

 

    TRANSMISSIONS:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Does Goerend Transmission still build full units in-house? 

At Goerend Transmission we no longer build full transmissions in house but do supply many customers with quality, time tested components to make your build as robust as possible. You have the option to rebuild it yourself, at a trusted shop, or at a Goerend dealer near you. Call for details (563) 778-2719, or find our list of current Goerend dealers on our "Installers" page. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How do I adjust the front band? (AKA: "Kickdown band" or "2nd Gear Band")

If your vehicle is equipped with a Goerend valve body, loosen the lock nut and tighten the adjustment bolt to 72 INCH pounds and finally loosen 2 ¼ turns (in other words a little over 2 FULL turns).

If your vehicle is equipped with a Stock valve body, tighten the adjuster to 72 INCH pounds and loosen 1 7/8 turns (in other words almost 2 full turns).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How do I adjust the Rear Band? (AKA "Reverse Band" or "Low & Reverse Band")

On a Goerend or Stock valve body: tighten the adjuster to 72 INCH pounds and loosen 3 full turns.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Flex Plate Insert Installation Instructions: 

flex-plate-insert-1.jpg  flex-plate-insert-instructions-1-larger-.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How much power will a Goerend Torque Converter hold?

With the proper valve body pressures, we have had our triple disc converters hold 1,400 horsepower and over 2,000 pounds of torque. Please contact Dave with questions regarding the single disc. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What makes a Goerend valve body different than the competitors or different than installing a valve body kit?

We like to keep the shifts as smooth as possible. We don't mean a slippery long drawn out shift, we mean a quick but smooth shift.

When you step into the throttle and the engine power goes up, the pressure in the trans also needs to go up. Our valve bodies have a much faster and steeper pressure rise than the factory or other valve bodies. 

A factory valve body normally has pressures at idle of 60 psi and the pressure at wide open throttle is near 100 psi. Goerend valve bodies will start at 70 to 90 psi at idle (depends on the customer and truck) and the pressure will go up to 150-190 psi at wide open throttle (again depending on the customer and truck circumstances). 

Some trucks have a problem while accelerating at about ¾ throttle and at about 40 mph. The transmission will neutralize and the engine will rev way up, just like it shifted to neutral instead of 3rd. Then you let off the throttle and it BANGS into 3rd gear, which is NOT NICE for ANYTHING. A Goerend valve body will correct this.

Many trucks have gear hunting from 2nd to 3rd - as long as the governor solenoid is in good shape a Goerend valve body corrects this. 

Most people who build valve bodies do not know that the torque converter circuit is regulated to 130 psi from the factory (they don't have the equipment to test the INTERNAL converter pressure, WE DO). It is common practice to eliminate this circuit and give the converter full line pressure, this is NOT GOOD and is the MAIN CAUSE OF BALLOONED CONVERTERS. A Goerend valve body has the proper regulation in the converter circuit.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Valve Body Application/Order Information:

Year

Transmission

Letter Code

91-93

47RH-Non Lock

A-NL

94-95

47RH

A

96-98 12V

47RE

B

98-99 24V

47RE

C

00-02

47RE

F

03

47RE or 48RE

X

04

48RE w/ Cable

X

05-07 5.9L

48RE w/ TTVA

W

 

Goerend High Pressure Valve Bodies are designed to run with a Triple Disc Torque Converter, a billet input shaft, a 3.8 ratio front band apply lever, and a Goerend heavy front servo spring.  If there is any variation from the above mentioned features, modifications will need to be made to the valve body to accommodate.

What Torque Converter do you have?     Stock  /  Billet Single  /  Billet Triple

What Input shaft do you have?    Stock  /  Billet

What front band apply lever ratio do you have?    3.8 (OK)  /  4.2 (some racing)   / 5.0 (must use a LP)

 

Stock lever on a 47 is 3.8, stock lever on a 48 is a 5.0, these are not Billet. The transmission must be pulled to change the lever. (The strap and anchor can be changed without pulling the transmission). If someone orders a 47 and is not going to change the lever, the ratio is the same so we can make the VB with slightly lower pressure. If someone has a 48 with 5.0 lever and doesn’t want to change it we would build a 48 (LP) an improved version of stock with the Goerend amenities that still uses lower pressure in 1st 2nd 3rd and boosted line pressure in Lockup and Overdrive.  (A normal Goerend VB runs higher line pressure in all forward gears). In some cases, if customer purchases the lever and plans to install it later, we can set the pressure low and send a note on where to set the Pressure regulator adjustment when the 3.8 lever is installed.

Automatic Shifting          or           Full Manual Shifting

Ranging Pressure             or            Constant Pressure

 

Constant pressure is usually recommended for high horsepower and racing applications, but lower constant pressure is also street-able and works well for 05-07 trucks with the TTVA motor.

Lock up Capability           1-2-3-4                  2-3-4

 

By default our 47 VB’s (A, B, C, F,) are hydraulically capable of locking the TC in 2-3-4 and our 48’s (X,W) are capable of 1-2-3-4.  The truck’s computer will not command lock-up in first gear – A manual lock-up switch is required.  Why would someone want first gear lock-up?  If you are mountain towing on steep grades under 10 mph locking the TC in first gear would keep the trans temp down.  Sled pullers normally want first gear lock-up.  Drag racers normally want 2-3-4 lock-up. They leave the switch ON then the TC locks as soon as the 2nd gear shift is made.  However, some racers have electronic controllers and want 1-2-3-4 lock-up. So it is up to driver preference.

 

Do you or will you have an Exhaust Brake?          YES    /     NO

With an exhaust brake, the VB needs to be capable of downshifting through the gears while the TC is locked to maintain engine braking.  All Goerend VB’s are capable of downshifting 4-3 while locked, but not all are made to shift 3-2 while locked.  So the Exhaust brake must be indicated so the VB can be built accordingly.

 

Vehicle Use? 

___(Daily driver/towing, normal street application)

___(Daily driver/drives hard, street racing, some drag racing or sled pulling)

___(Drag racing or sled pulling primarily/some street use)

___(Dedicated drag racing or sled pulling)

Power Level?

___(Stock – 500)

___(500 – 700)

___(700 – 900)

___(900 – 1000+)

Electronics Selection

A-NL (47RH Non-lock) 91-93: 2-pin connector, Overdrive solenoid only (mechanical governor)

A (47RH) 94-95: 3-pin connector, Lock-up and overdrive solenoids only (mechanical governor)

B (47RE) 96-98 12 valve:                                                                                     

C (47RE) 98-99 24 valve:

Comes with: LU/OD solenoids, Steel governor pressure sensor, Borg Warner Gov. Solenoid (resistor to help prevent Governor over pressure codes) Optional upgrades – GM Governor Solenoid (additional charge) VBA, to replace the resistor (additional charge)

F (47RE) 00-02: (resistor to help prevent Governor over pressure codes)                             

X (47RE/48RE) 03-04 With TV cable:  (47 comes with resistor)                                                                                                                      

W (48RE) 05-07 With TTVA Motor:

Comes with: LU/OD solenoids, high pressure plastic governor pressure sensor (white back), Borg Warner Governor Solenoid.  Optional upgrades – GM Governor Solenoid (additional charge), BD adapter with steel sensor (additional charge) The BD adapter has a built in voltage limiter, so the resistor is not needed on F & X    

 

Goerend Transmission uses all new electronics on our Valve Body builds. These electronics are tested for proper function on our Valve body tester with Superflow Windyn and Supershifter Pro software.  We do not manufacture these electronics, so therefore we cannot warranty them.  Please keep all of the electronics from your valve body core in case you should need a back-up solenoid or sensor at some point.  The plastic governor pressure sensor on the 00-07 trucks seems to be the most problematic. Although the high-pressure version that we are currently using has been performing much better than the original, these still fail occasionally.  The BD adapter utilizes the pressure reading from the early style steel governor pressure sensor (which is much less prone to failure) and keeps the voltages within the computers parameters to prevent fault codes. It also has a built in temperature sensor that reads the same as the late style plastic sensor to be compatible with the truck’s computer.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What are the pressures on our valve bodies? 

You can get a Goerend valve body with pressures ranging from 70 PSI at idle to 190 PSI at wide open throttle (WOT). Your driving habits and what you use the truck for will dictate what pressures you will need.

We also have constant pressure valve bodies where the pressure is fixed - in other words the pressure is the same at idle as it is at wide open throttle.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is a Constant pressure valve body and why would I need one? 

Normally the pressure that applies the clutches and bands in a transmission will be low at idle and high at wide open throttle. With a Goerend constant pressure valve body the pressure is high at all times, while at idle and wide open throttle.      

A constant pressure valve body is normally used for trucks that are racing or with engines that have high power.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Can I install a valve body with a stock 2nd band apply lever?

We have seen the stock 2nd band apply lever break with stock valve body pressures, not often but we have seen it happen. If you are installing a valve body with higher pressures we recommend you remove the transmission and install a lever made with a stronger material. 

We do make a stock pressure valve body with all the other features in our high pressure valve bodies.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Will a new valve body cure all my shifting problems? 

Many shifting problems can be cured by a valve body, BUT the shift timing (when it upshifts and downshifts) is controlled by the computer. On a 1995 and older the 3-4 and converter lock up is computer controlled, on a 1996 and newer ALL shifts are controlled by computer.

Just like any computer: bad info in = bad info out, so if you have a bad input to the computer, like a bad throttle position sensor or output shaft speed sensor, they can affect the shifting and that would seem like a valve body problem but is not a valve body problem.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is the difference between a towing, sled pulling or drag racing valve body?

On a towing valve body we want a smooth shift, not a slippery soft shift but a smooth shift, this helps keep shafts and planetary gears from breaking due to the high “shock” of brutal shifts.

We would also build the valve body so you can downshift from 4th to 3rd and 3rd to 2nd with the converter locked in case you have an exhaust brake.

If a toggle switch is installed you can also lock the converter while in manual 2nd so the converter will not overheat while towing a heavy load up a steep grade.  

On a sled pulling valve body you most likely will want the converter clutch to be capable of locking in 1st, 2nd, 3rd and overdrive and also be able to back shift from overdrive to 3rd, 3rd to 2nd and 2nd to 1st with the converter locked.

On a drag racing valve body we normally lock the converter right after the 1-2 shift. 

We can make the valve body so it will NOT lock the converter in 1st, that way you can turn the lock-up switch on while at the starting line and it will not kill the engine and as soon as it shifts to 2nd the converter will automatically lock up, hands free so to speak.   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is there one valve body that will work well for daily driving, towing, drag racing and sled pulling?

Yes and no. 

Up to about 500 horsepower you can use the same valve body and it can work well for all, but, once we get above that there are things that we need to do to the valve body that would be specific to drag racing and sled pulling that we would NOT do to a daily driver or tow rig.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Where does the big spring go that comes with the new valve body? 

This spring goes into the front band apply servo ALONG WITH the original spring. This is the servo that applies the front band.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Do all valve bodies need the extra spring for the front band apply servo? 

All GOEREND HIGH PRESSURE and CONSTANT PRESSURE valve bodies NEED the spring. We do make valve bodies that are not as high a pressure and do not require the extra spring. These valve bodies have all the same upgrades as the high pressure valve bodies - only with pressures that are slightly above stock. These valve bodies are for people who want to install a valve body only and do not have to remove the trans to install the billet 1-2 shift lever.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What trans fluid should I use and should I use an additive? 

These transmissions first used Dexron trans fluid, then Chrysler 7176 fluid, then Mopar type 3 and now Mopar type 4. 

We have used all of the above without any problems. 

There are many good fluids you can use, most synthetics are fine. You can use Dexron 3 or Dexron/Mercon alone or with a Lubegard additive - NAPA PART # 765-2603 (part number is subject to change).

We DO NOT use Dexron 6 or any other additive other than Lubegard. 

DO NOT USE TYPE A / SUFFIX A fluid. This is for 1966 and older transmissions.

Type F will give a firmer shift but we do not recommend it, or Type CJ.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is different about a Goerend converter compared to others? 

We design our own converter components and make them here. This ensures that our dimensions are correct and will work with your transmission. 

We build our converters in house from start to finish, we make the billet covers, the billet clutch dampners, the stators, the stator caps and more.

We make our own billet front covers and clutch pistons out of forgings and this greatly reduces any chance of porosity.

Our stators are designed like an airfoil, this produces lift to help the stator rotate when going into the coupling mode and also creates a venturi effect to help torque multiplication. 

Have you ever had a converter that you have to let off the throttle petal to get it to lock up and then be told by the converter builder that is the way they designed it so the clutch does not lock up under too much power?? There is no designing you can do inside the converter to make it NOT LOCK when the valve body has given the command. 

Our PATENTED internal design insures that the torque converter clutch WILL LOCK up when the computer and valve body give the signal. 

NO MORE LETTING OFF THE THROTTLE OR “FEATHERING THE THROTTLE” TO GET THE CONVERTER CLUTCH TO LOCK UP.

On Allison converters the impeller and turbine are furnace brazed from the factory, the Dodge impeller is also furnace brazed from the factory BUT the Dodge turbine on the 47/48 transmissions are not Brazed from the factory. These parts are brazed in a HUGE oven and when ALL the parts in the oven are the same (size and thickness) the brazing temp and time in the oven can be set for that specific part and the end result is good with no warped parts.

If different size and thickness parts are brazed in the the same batch the oven temp and “bake” time must be high enough and long enough for the parts that need the highest temp and longest “bake” time, this can lead to “overbaking” and overheating smaller or thinner parts resulting in warped parts. We often see this in converters we cut apart and of course we WILL NOT reuse one of these. Instead, we MIG WELD the fins on ANY turbine or Impeller that has not been FACTORY brazed and we WILL NOT use any warped parts. 

If the stall speed of the Impeller or turbine needs to be changed and the fin angle must be changed, we WELD the fin in that position. Yes it does take longer to do this but if you move a blade you MUST secure it so it does not bend back to the original position or possibly break. 

We use Raybestos or Borg Warner clutches in our converters. We feel it is hard to beat the quality and engineering capabilities of these companies that have been doing this since the early days of the Automobile.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Converter rebuild procedure 

1. Converters are drained and cut open

2. All parts are cleaned and inspected

3. Front covers, clutches, bearing, seals, & springs are all replaced

4. All Dodge impeller hubs are replaced with new

5. Impellers, turbines, stators, clutch and dampers assemblies and billet front covers are ALL balanced individually BEFORE they are assembled

6. The converter is then assembled

7. Dave then personally disassembles each converter and checks all components and after over 25 internal and external dimensional checks are made, our converters are welded together by TCRS alignment equipment with .003 runout or less

8. The converter is then leak checked under water, under pressure

9. The converter is then balanced as a unit and the run out is checked again

10. The total height is checked

11. The internal end play is checked

12. The lock up clutch is applied and checked for leaks and holding power

13. The lock up clutch is then released and the clutch and turbine is spun while holding the impeller stationary to make sure the clutch releases properly and that there is NO interference between any internal parts

14. The hub is lubricated and a protector is installed

15. New converter to flexplate bolts are provided where necessary

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is stall speed?

Stall speed is the highest rpm (engine revolutions per minute) that the engine can achieve while you are IN GEAR NOT MOVING WITH THE THROTTLE HELD TO THE FLOOR. 

(WE DO NOT RECOMMEND THIS TEST AS IT CAN DAMAGE MANY THINGS)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What determines the stall speed?

The 2 major things that determine the stall speed are the engine torque and the torque converter. Here are a few different ways to think about it:

Lets say you are on an exercise bike that uses a large fan for the “load”. The smaller the fan the faster you can pedal it, the larger the fan the harder it is to pedal it so your max rpm would be slower. Lets say with a small fan you can do 200 rpm and no faster, that means your “stall speed” is 200 rpm. With the large fan lets say you can only petal it 50 rpm, the larger fan stalled you at 50 rpm with the same person on the bike, 2 different fans, 2 different stall speeds.

Now, lets put a different person on the bike, how about a bodybuilder with huge legs. With the big fan this person may be able to petal 100 rpm as opposed to your 50, same fan different person to liken this to the engine and converter you have to remember that the converter is nothing more than 2 fans, one fan is connected to the engine and the other is connected to the transmission. The fan that is connected to the engine blows oil at the transmission fan and when it blows enough oil at it the transmission fan will start to rotate and the vehicle starts to move. In this scenario with the engine and converter the same is true if you install a converter with “bigger fans”, the stall rpm will be lower with smaller fans the stall rpm will be higher if you add horsepower to the engine (just like the bodybuilder) the stall rpm goes up.

Now lets talk about air, its all about the air, or oxygen. The person on the bike can pedal harder at sea level than on the top of a mountain because they can breathe better because there is more oxygen at the lower elevation... The air is more dense, same with the engine. The engine is nothing more than an air pump that uses fuel, the fuel MUST burn, expand and push the piston down. You MUST have oxygen to burn the fuel, the higher the elevation, the less oxygen we have so the less fuel we can inject. Less fuel means lower power into the converter and hence a lower stall speed. Normally the higher in elevation you are the higher the stall speed you need. The engine turbocharger also can make a huge difference, the turbo is also a set of fans, the drive fan is located in the exhaust of the engine and the exhaust flow makes this fan spin. The driven fan of the turbo is connected to the drive fan and sits in the intake side of the engine and forces fresh air (more oxygen) into the engine so we can burn all the fuel or burn more fuel to get more power. When you have a turbo with bigger ”fans“ it takes longer to “spool” them up or in other words it takes longer for the turbo to spin up and start to blow more air (oxygen) into the engine. If it takes longer to spin up it takes longer to get the extra oxygen needed into the cylinders to burn the fuel, this is called turbo lag

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Stock VS. Billet Allison Stator Information
ATTENTION: Stock Stators ARE NOT WARRANTIED
•Billet Stators have a Heavy Duty Stator Warranty
•Stock Stators DO NOT HAVE A WARRANTY

DO NOT USE A STOCK STATOR (with stock horsepower OR with modified horsepower) FOR:  

Sled pulling, drag racing, boosted launches, ETC.  

Below are some images of what could happen if you are doing boosted launches with a stock stator: 

stock-stator-explosion-goerend-billet-stator-pic-006.jpg   allsion-tc-parts-001.jpg   allsion-tc-parts-003.jpg

 

At Goerend Transmission we make Goerend Billet Stators that are GUARANTEED not to break. Below is a picture of one of our Low Stall Stators being machined.

stock-stator-explosion-goerend-billet-stator.jpg

 

We sell to many companies that resell our products. If you ordered a billet stator, here is one of the ways to check that it does have a Billet Stator:
The following Goerend Converters have a BILLET STATOR:
E, G, H, J, K, P, R, S, T, W, X
A "K" Converter is only available through Inglewood Transmission. 
The following Goerend Converters have a STOCK STATOR:
A, B, C, D, F, N 

See the picture below to find where to look for the stamping on a GOEREND TORQUE CONVERTER to determine if the converter LEFT GOEREND TRANSMISSION with a STOCK or a BILLET STATOR. 

pic-for-website-of-stamping.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dodge 1740 Code

On a late model truck, usually 2004 – 2007, any stall speed different than the factory stall ( 17SS ) can set a 1740 code, this code will turn on the check engine light BUT will not affect the operation of the trans or the engine. This code sets because the computer constantly monitors the engine rpm and compares it to throttle angle and road speed. With a lower stall converter the computer sees the lower engine rpm and assumes the lock up or overdrive solenoid is mechanically stuck on (the computer can check for electrical faults and does not see any) and assumes the lower rpm is due to the converter being locked up or the trans is in overdrive when it is not. Most programmers can erase the code.

Again, this code will NOT affect the transmission or engine operation; it will just illuminate the light.

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is the difference between a GOEREND transmission pan and others?

We designed our own pan to get several features that we could not find in other pans.

1.     We have a sloped floor on the inside of the pan so ALL of the fluid drains out.

2.     Our drain plug takes a 1” socket: no more stripped allen heads or threads.

3.     Our drain plug is magnetized and is at the lowest point in the pan so it WILL catch any magnetic debris; some others sit above the bottom of the pan and can't catch the steel shavings.     

4.     The exterior of our pan is flat so the trans will sit on a jack without rocking.

5.     The sides of our pan are NOT ribbed for strength. If you hit a rock or something else we want the transmission pan to break away. Pans that are excessively beefed up on the side may not break and you may break your transmission case instead. It is much easier and cheaper to replace the transmission pan than the transmission case.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What transmission filter should I use?

There are 2 different transmission pans that were used from the factory on these transmissions.   The pan that is completely flat on the bottom is the deeper pan and should take the plastic filter because it sits deeper in the fluid.

If you have a deep aluminum pan that uses a filter lowering block I would use the “open” element filter that has the paper filtering element on both sides because it fits the lowering block better.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When accelerating at about ¾ throttle at about 40 mph my trans seems to shift to neutral and the engine revs to redline. What can I do?

As long as the governor solenoid and control circuit is capable of producing good governor pressure, a GOEREND valve body will cure this problem. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal Transmission Temperatures & Sender Locations

Dodge 47/48 series Diesel Transmissions

 

There are 3 basic places to install a temp sender for the transmission; the transmission pan, the front cooler line, or one of the transmission case pressure tap ports. There are pros and cons to each location.

Many people like to install the sender at the front cooler line. This location will give you the temp of the fluid coming out of the converter and will be the hottest temp you will see from the trans while in the fluid coupling mode (converter clutch unlocked).

On the ’94-’95 transmission there is a temp sender already in the front line that gives info to the transmission computer so it will not let the trans go to 4th or lock the converter clutch until the transmission and engine are warmed up. At prox 70° F it will take approximately ½ mile of driving before the computer will command a 3-4 or lock up shift. At approximately 30° F it will take about 3 to 4 miles before it is warm enough for the 3-4 / lock up and if the ambient temp is below 0 it can take 5 miles or more.

Bottom line, if you have a ’94-’95 this sender must stay in the line. If you are going to install a gauge sender in this line you must make some sort of manifold to install the second sender. The original sender MUST be in contact with the fluid - taped to the line is not good enough. One problem with a manifold set up for the sender is that it adds weight and the extra weight coupled with vibration could crack the line and cause a leak that you would only see when the engine is running.

90% of the heat in a properly operating automatic transmission comes from the torque converter fluid coupling. The fluid coupling is when the drive fan  (connected to the engine) of the converter is blowing oil at the driven fan (fan connected to the trans input shaft). Once the converter clutch (single disc or triple disc) locks the fans together, all of the power is transferred to the input shaft. Because the fluid is not being used to transfer the power while in “lockup”, no heat is transferred to the fluid. The more efficient the fluid coupling is, the cooler it will run WHILE YOU ARE MOVING. An efficient converter (fluid coupling) will run hotter when you are in gear but not moving. This is because when you are not moving, the engine fan of the converter (impeller) is still moving with the engine and trying to transfer the power (heat) to the driven fan (turbine). If the driven fan is stationary, as would be while at a stop sign, the power has no place to go but into the fluid and out to the cooler as heat. On the other hand, when you are up to speed and the converter clutch locks the 2 fans together, you are now transferring 100% of the power to the rear wheels and the power (heat) will be transferred to the rear wheels. When the lock up occurs you would see an immediate drop in fluid temp of about 20° F.

Normal temps of the transmission fluid will fall in the area of about 100 to 280° F depending on where you check it.

 

Pros for the cooler line location:

You will only see the full range of temperature at the front cooler line.

Normal temps when monitored at the front cooler line would fall in the range of about 140° F to 280° F

While watching the temp at the front cooler line you can instantly see the temp climb if you are pulling a heavy load. You can also see the temp fall almost instantly when you back off the throttle and you can also tell that the converter clutch was COMMANDED to lock, because the temp will drop instantly even when under heavy load when the converter clutch is COMMANDED to lock up.

The cons of this location, and one of the reasons I prefer the sender in the pan is because if we are monitoring the gauge this close your eyes are not on the road. This is a very active gauge when the sender is in the front cooler line. The sudden and extreme range of temps you will see may make one nervous even though they are well within the norm at this location.

 

Just the opposite is true if you install the gauge in one of the pressure ports of the transmission case. The fluid at any of these test ports is stagnant oil, once the oil gets to the test port it is at a dead end and is no longer circulating. At one of these locations we will really be reading the temp of the transmission case. At these locations it will take the longest to get a reading, and by the time you see a reading above 200° the converter temp was probably around 250° - 270° for quite some time because it takes a while for the heat to radiate into the case and once the fluid cools it will also take a while for the case temp to drop, back to that radiation thing again. At this location expect to see normal temps range from about 140° to 190° - if the temperature reaches above 200° I would find a place to pull over.

 

Pros for the pressure test port location would be ease of install and multiple locations to use.

Cons for these locations would be slow gauge reaction time and also we need to make sure the sensing tip of the sensor is not too long and bottoms out before you have the sensor tight.      WE DO NOT RECOMMEND THESE LOCATIONS

 

We like to install the temp sender in the trans pan. The gauge will react quick enough to save the trans form overheating and yet the gauge won’t be so active that it would make one nervous about the temp extremes. The normal temp range you would see will be about 140° to 200°. If the trans temp gets above 200° F we would want to get the engine rpm above 1500, I will explain why. Fluid that is cold does not move very quickly through small passages, like the small passages in the valve body. Fluid that is too hot is hard to pump because it is too thin.

 Fluid at 230° does not hurt the seals, gaskets, or clutches, but, because it is so thin it is hard for the pump to maintain enough flow so the valve body can maintain enough pressure in all the circuits. At approximately 200° in the trans pan even a good pump will have a hard time flowing enough fluid to satisfy all the circuits when the pump rpm (same as engine rpm) is below about 1,300 rpm. If the pump can’t maintain the volume of oil and the pressure regulator valve cannot maintain good pressure, the clutches and bands will slip. The cooler flow and pressure will also be lower and this will escalate the heating problem. This can easily be seen on the transmission dyno where we can monitor trans temp, clutch pressures, cooler pressures and volumes. Even with hot fluid above 200° these pressures and volumes come back to normal when we bring the rpm close to 1,500.

With 4.10 gears this is not really a problem because the engine rpm will not be around 1,500, but, with 3.54 gears you can easily be at 60 mph or lower with the converter locked up and the engine rpm could be around 1,500. All depending on tire diameter, of course.

For the above reasons alone we do not like to get the converter stall too low, lets say someone wants an extremely low stall converter and they are going to do a lot of snow plowing, the engine and customer may like the low rpm but if you are working things especially with the converter clutch unlocked at low rpm the pressure and cooler flow may suffer.

 

Hope this clears things up for you as far as sender locations are concerned

If you have any questions just call Dave @ 563-778-2719

 

Thanks

Dave G