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what does it mean when the torque converter locks up

by Keven Morar Published 1 year ago Updated 1 year ago

If you’re unfamiliar with exactly what the torque converter lock up is or does, the easy answer is, the lock up clutch takes stress off the fluid coupling of the torque converter and it helps decrease the amount of heat being generated at higher cruising speeds. Converter lock up wasn’t really an issue until the overdrive came about.

When the converter is “locked up” this clutch is forced against the front of the converter creating a direct drive from engine to transmission. If you're working with an older mechanically controlled automatic with a lock up converter there are several variations of lock up kits available on the market today.May 5, 2020

Full Answer

What does it mean when a torque converter "lock up"?

If you're unfamiliar with exactly what the torque converter lock up is or does, the easy answer is, the lock up clutch takes stress off the fluid coupling of the torque converter and it helps decrease the amount of heat being generated at higher cruising speeds. Converter lock up wasn't really an issue until the overdrive came about.

What speed does torque converter lock up?

Torque Converter locks up at 25 mph no matter what throttle. Listen to how the car shifts then locks up at exactly 25 mph. You can easily unlock it by giving it 25% throttle, then again the torque converter readjust and locks up with steady throttle. You can activate the lockup clutch anytime after 25 mph with steady throttle.

When does the torque converter lock up?

Once the ground is established, that completes the circuit in the timing module which is receiving a +12 volt signal from the fuse panel. This completed circuit activates a 10 second delay timer that when finished, connects the ground signal to the torque converter lock up solenoid, thus locking the converter clutch in.

Can a torque converter lock up an engine?

Can a torque converter lock up an engine? There are basically three ways a torque converter lockup clutch can fail: It can stay locked up , stalling the engine when the car is braked to a stop; it can never lock up , which shows up as an increase in fuel consumption and radiator temperature; or it can slip when engaged, allowing engine speed ...

What causes a torque converter to lock up?

Engine temperature too cold - most converters will not lockup until the coolant reaches about 120°F. 2. Overdrive unit locked out - when an automatic overdrive is "locked-out" the torque converter lockup feature will also be locked out.

How do you unlock a torque converter?

1:045:48Torque convertor, how to get it to unlock on hill. - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou just tap the brakes just enough to get the brake light to come on you're knowing the brake lightMoreYou just tap the brakes just enough to get the brake light to come on you're knowing the brake light come on because the torque converter will unlock.

How do I know if my torque converter is locked?

1:435:38How To Tell If Your Torque Converter Is Locked Up - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo you don't stall. But when you are going fast enough and you're cruising. The torque converterMoreSo you don't stall. But when you are going fast enough and you're cruising. The torque converter will engage the clutch. And basically what it'll do is it'll mimic a manual transmission.

What does it mean to lock your torque converter?

However, when the engine turns more slowly it causes the torque converter to slip, creating heat. Slipping reduces fuel economy and heat can damage the converter and the transmission. The solution is to lock the converter. Lock-up eliminates the slippage, which reduces heat and improves fuel economy.

What happens when torque converter fails?

When the torque converter starts malfunctioning, you may feel shuddering and even slipping in overdrive. You usually notice your car shuddering because it feels like it's vibrating. Your car will vibrate even when you're not going very fast. The shuddering makes the car lag and is very noticeable.

Does a torque converter lock in every gear?

As far as I know most torque converters do not lock up until 3rd gear, regardless of throttle. Modern transmission are entirely controlled by the ECU, so shifting gears while the torque converter is locked happens all the time without issue, but I get the feeling that's not what you're asking?

How much does it cost to replace torque converter?

Most auto repair shops will charge someone anywhere from $600 to $1000 for a torque converter replacement job. If you would rather do the replacement job yourself, then a new torque converter will cost anywhere from $150 to $500. The exact cost depends on the make and model of your vehicle.

Can you replace just the torque converter in a transmission?

Repair shops will charge between $600 and $1000 to replace a torque converter. The torque converter itself is relatively inexpensive (between $150 and $350, depending on the vehicle), but 5-10 hours of labor is involved since the transmission must be removed in order to replace the torque converter.

Can a torque converter lock up an engine?

There are basically three ways a torque converter lockup clutch can fail: It can stay locked up, stalling the engine when the car is braked to a stop; it can never lock up, which shows up as an increase in fuel consumption and radiator temperature; or it can slip when engaged, allowing engine speed surges at a constant ...

How do you fix a torque converter clutch circuit stuck on?

What Repairs Will Fix P0742?Replace the torque converter clutch solenoid.Replace the torque converter or clutch.Change transmission fluid and filter.Repair/replace damaged wiring and connectors.Repair/replace TCM or ECU.Install a rebuilt or remanufactured transmission.

Does torque converter affect acceleration?

By redirecting fluid flow, the converter multiplies the torque produced by the engine enough to propel a vehicle down the road. Most converters multiply torque by a ratio of at least 2:1, improving vehicle acceleration substantially.

How do you unlock a transmission?

1:203:40DIY how to electronically unlock the transmission lock - YouTubeYouTubeStart of suggested clipEnd of suggested clipStep on the brake pedal during the entire unlocking procedure press the start/stop button press andMoreStep on the brake pedal during the entire unlocking procedure press the start/stop button press and hold the unlock button on the gear selector.

How do you unlock a transmission?

1:203:40DIY how to electronically unlock the transmission lock - YouTubeYouTubeStart of suggested clipEnd of suggested clipStep on the brake pedal during the entire unlocking procedure press the start/stop button press andMoreStep on the brake pedal during the entire unlocking procedure press the start/stop button press and hold the unlock button on the gear selector.

Can a torque converter lock up an engine?

There are basically three ways a torque converter lockup clutch can fail: It can stay locked up, stalling the engine when the car is braked to a stop; it can never lock up, which shows up as an increase in fuel consumption and radiator temperature; or it can slip when engaged, allowing engine speed surges at a constant ...

What is a non lock up torque converter?

Towing will add heat to the transmission. A non-lock-up torque converter will add more heat. With a lock-up when you get to speed, the torque converter will lock-up, which creates a direct drive from engine to transmission. No additional heat will be added into the tranny fluid due to slippage during operation.

How do you bypass a TCC solenoid?

To bypass the shift and TCC solenoids, you simply need to connect standard 194 light bulbs to these individual circuits coming from the PCM and then connect the other side of the bulbs to ignition B+. The light bulbs will then serve as a "load" which will simulate the solenoids.

What happens when torque converters slip?

With slippage comes heat which, in turn, leads to the loss of fuel economy. To do away with the underlying issues, a lock up clutch is thus introduced.

What is torque converter?

What Is A Torque Converter? Torque converters are similar to fluid coupling (device for passing rotating mechanical power) that holds the capability to transfer power from an internal combustion engine to the driven load.

How fast does a lock up clutch work?

A lock up clutch is engaged as soon as the engine and the transmission run at the same speed approximately. The speed at which a lockup mechanism automatically activates is about 64 kph. For transmission to lockup, however, some requirements follow.

What is torque converter lock up?

Torque converter lock up is one of those things that can be easily overlooked in the normal operation of any newer automatic transmission. With the computer controlled transmissions we are used to driving today the converter will lock and unlock without us ever realizing what’s going on. The lock up converter was introduced in the late 1940’s, but due to the extra costs, it never gained popularity until the late 1970’s when the energy crisis demanded a more efficient operation of automatic transmissions. Most of us hot rodders always think of the GM 700-R4 & 200-4R transmissions as our first experience with setting up a lock-up converter, as they are still very popular today.

What does lock up clutch do on torque converters?

If you’re unfamiliar with exactly what the torque converter lock up is or does, the easy answer is, the lock up clutch takes stress off the fluid coupling of the torque converter and it helps decrease the amount of heat being generated at higher cruising speeds.

How does a cruise control brake switch work?

We also include a cruise control style brake switch that works perfectly to disconnect the +12 volt power to the lock up module when the brakes are applied. This pulls the converter out of lock up to allow the car to easily accelerate back up to speed before the lock up re-engages.

What does it mean when a transmission has a 5th gear?

Most of the time you never notice this transition as it is essentially seamless, but with some of the older 4 speed automatics it will seem as if the transmission has a 5th gear or extra over drive when the converter locks up since it will typically reduce engine speed by a few hundred RPM. Torque converter lock-up is engaged through ...

How does a timing module work?

The solution was a timing based module system that activates the converter only after the transmission has shifted into 4thgear. The basic operation is quite simple. When the transmission has shifted into 4th gear, the pressure in the valve body closes a pressure switch that then creates a ground input. Once the ground is established, that completes the circuit in the timing module which is receiving a +12 volt signal from the fuse panel.

When was the lock up converter introduced?

The lock up converter was introduced in the late 1940’s, but due to the extra costs, it never gained popularity until the late 1970’s when the energy crisis demanded a more efficient operation of automatic transmissions. Most of us hot rodders always think of the GM 700-R4 & 200-4R transmissions as our first experience with setting up ...

Can you install a lock up system?

The entire lock up system can be installed by anyone with minimal mechanical skills. The internal components are all accessed by removal of the transmission pan and filter only. There are no special tools or procedures required. We include every component needed to connect the system and get it working properly. This ensures that whether you have a newly re-built unit, or a unit that has been in service for years, all the parts are there and correct for proper operation.

Why is my torque converter not locking?

It is worth noting that a torque converter may not lockup for the following reasons: A cold engine temperature: There are cases where the converter may not lockup except the coolant temperature reaches 120°F. Lockout of the overdrive unit: An overdrive unit that is locked-up causes the torque converter lockup to also be locked out.

What Is a Lockup Torque Converter?

Lockup torque converters are a type of converter that has a clutch. The engagement of this clutch causes the engine to lock to the transmission input shaft thereby leading to a direct 1:1 drive ratio. A lockup torque converter is used since it offers fuel economy, enabling you to use fuel minimally while on that joy ride.

How does torque converter affect transmission?

As the torque converter slipped, it generated heat, which could potentially affect the converter and transmission negatively. This heat also impacted on fuel economy, thereby overriding the purpose the overdrive was used in the first place.

Why is a lockup torque converter important?

A lockup torque converter is important in automatic transmissions to reduce slippage. And once slippage is curbed, heat generation is minimal while fuel economy is improved. This and many more have been outlined above to give you an insight into this component and why you may need one.

How does a lockup converter work?

In this case, there is a lock of the turbine to the torque converter’s case by the hydraulic pressure and this occurs when the crankshaft and input shaft are to turn at the same time while driving.

What causes a lockup clutch to rotate?

The engagement of the lockup clutch causes the fluid in the converter to rotate and at a speed similar to other components of the converter. The good thing is, heat is curbed significantly and so is the oil turbulence. The movement of the fluid can be attributed to the circulation which cycles the fluid through the cooler.

Why is a lockup torque converter called a slushbox?

Lockup torque converters gained popularity when it was discovered that manual transmissions are more fuel-efficient than automatic transmissions . The old torque converters also led to a loss in RPM between the gearbox’s crankshaft and input shaft. For this reason, it earned automatics the name slushbox at the time.

How does a torque converter work?

For example, if you run two fans against each other and start one of the fans, the other fan will also begin to rotate, but not directly at the speed the other fan has. This is precisely how a torque converter works.

How to diagnose a torque converter?

To diagnose it correctly and carry out a visual inspection, you must remove the vehicle’s transmission and engine. Some older American cars have a cover plate that you can remove to inspect the torque converter. But even with them, you will not see much because the torque converter is a sealed unit.

What does slipping torque converter mean?

A slipping torque converter will wear out the transmission very quickly. In some cases, you may have temperature sensors that cause the transmission control unit light on your dashboard to flash, which indicates that your torque converter is slipping and overheating the transmission.

What causes a torque converter to idle?

If the torque converter is faulty, it might create unexpected pressures inside the torque converter, which can cause rough idling.

How to tell if torque converter is accelerating?

Check whether you can feel or hear strange noises from the torque converter both when idling and accelerating. Listen in the middle of the car under the gear stick to see if you can hear knocking or other strange sounds.

What is a symptom of a defective torque converter?

A widespread symptom of a defective torque converter is that the transmission slips when accelerating.

Why won't my car move in drive?

Car won’t move in drive or reverse. If your car does not move at all in drive or reverse gear, a completely failed torque converter could be the cause. However, a car that does not move in gear can be caused by many different things, and it should be properly diagnosed before replacing anything.

What is a lock up converter?

On a "lock-up" converter (I think they only "lock" in high gear at cruise/light load ) the tc housing and impeller are somehow "locked" together - meaning you'll get that 1-to-1 connection between the flywheel and output shaft. The result is a little less (gas saving) rpms at cruise.

When does a TCC unlock?

The TCC unlocks when you push the brake or try to accerlate to some degree. This allows torque multiplication in 3rd and even 4th if the tranny is allowed and aids in pulling in those higher gears. You can feel the TCC working when you drive these vehicals. NON-LOCK - basic, just like the old TC's of C4, C6 alike.

Why does it take more time to get a car moving on the interstate?

Also when on the interstate and you go to accelerate quickly, it is going to take more pedal movement and more time to get the car moving with a non lockup because the impeller acts like a buffer.. you have to wind up the rpms before the car will "take off" like you are used to.

Does Edge make a non lockup?

Edge can make a non lock-up that works with the stock input shafts.#N#If your car is a daily driver or do a lot of interstate driving I would stay lock-up. non-lockup is great at the track but not so great for daily driving.. plus like mentioned it builds a lot of heat because the torque converter is ALWAYS slipping unless you are driving at a constant speed for a long period of time. When driving for a long period of time at a constant speed the TC achieves "fluid coupling" whenever the engine and torque converter impeller actually reach the same speed so 0 slipping occurs but this doesn't happen very often.. Also when on the interstate and you go to accelerate quickly, it is going to take more pedal movement and more time to get the car moving with a non lockup because the impeller acts like a buffer.. you have to wind up the rpms before the car will "take off" like you are used to.

Can you use 2 PCs in a non lock converter?

You can use the stock 2 pcs inputs for some manufacured non-lock converters - only some require a 1 pc , that is becuase they are BEEFING the input shaft and using the C6 splines that requires a different turbine inside the converter.

Can you use stock 2 PCs inputs?

Long trips. You can use the stock 2 pcs inputs for some manufacured non-lock converters - only some require a 1 pc, that is becuase they are BEEFING the input shaft and using the C6 splines that requires a different turbine inside the converter. There you go.

Is 3rd gear bog lockup?

the 3rd gear bog will not be any greater than what you ALREADY feel now, your converter is a lockup unit now.

What is torque converter?

The torque converter converts hydraulic pressure within the transmission to mechanical torque, which drives the drive shafts and ultimately, the wheels. When the car is in low, second and reverse gears the converter operates in hydraulic or soft drive.

How to get torque multiplication?

To get torque multiplication, we must return the fluid from the turbine to the impeller and accelerate the fluid again to increase its force on the turbine. To get maximum force on the turbine vanes when the moving fluid strikes them, the vanes are curved to reverse the direction of flow.

What causes a TCC to disengage?

The TCC solenoid is what actually causes the TCC to engage and disengage. When the TCC solenoid receives a signal from the ECM, it opens a passage in the valve body and hydraulic fluid applies the TCC. When the ECM signal stops, the solenoid closes the valve and pressure is vented causing the TCC to disengage.

What is a TCC clutch?

The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid-operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. Lockup reduces slippage in the converter increasing fuel economy. For the converter clutch to apply, two conditions must be met:

How does a rotating impeller work?

The rotating impeller acts as a centrifugal pump. Fluid is supplied by the hydraulic control system and flows into the passages between the vanes. When the impeller turns, the vanes accelerate the fluid and centrifugal force pushes the fluid outward so that it is discharged from openings around the inner ring.

What are the conditions for a converter clutch to apply?

For the converter clutch to apply, two conditions must be met: Internal transmission fluid pressure must be correct. The ECM must complete a ground circuit to energize the TCC solenoid that moves a check ball in the fluid line. This allows the converter clutch to apply when hydraulic pressure is correct.

How fast does a TCC go?

Generally, the TCC will engage at about 50 mph and disengage at about 45 mph.

How Does a Torque Converter Work?

To understand how a torque converter works, start by picturing two fans sitting face-to-face. One fan, the impeller, is powered because it’s connected to the engine. The other fan, the turbine, is not plugged in because it’s connected to the transmission. When the plugged-in fan spins , the other fan rotates as well . The same effect is happening inside a torque converter, but it’s the hydraulic fluid that moves the fans instead of air . A simple step-by-step overview of this complex process is outlined below.

Why is torque converter needed?

This is required to have enough power for acceleration. While a car is in operation, the engine must always be running. However, when the vehicle stops, the wheels, axles, and driveshaft are no longer spinning.

How Much Does It Cost to Replace a Torque Converter?

A torque converter can cost around $300-$600 to replace. The total amount will be closer to $1,000 if labor is included.

How does a stator work?

The stator receives fluid from the turbine and flings it back towards the impeller, multiplying the amount of torque produced. The torque multiplication is especially powerful when the impeller and turbine are spinning at very different speeds. Fluid - The torque converter housing is filled with transmission fluid.

What is torque converter?

A torque converter takes the place of a clutch in cars with an automatic transmission. Unlike a manual clutch, it uses fluid to transmit mechanical power from the engine to the transmission. While a manual transmission has a flywheel and clutch discs, automatic transmissions have a flexplate and torque converter.

What are the components of a torque converter?

The major components of a torque converter are the impeller, the turbine, and the stator. There’s also the fluid itself, and often a lock-up clutch. All are contained within the housing of the torque converter, which connects to the engine’s flexplate (sometimes called the flywheel).

What happens when a vehicle stops?

However, when the vehicle stops, the wheels, axles, and driveshaft are no longer spinning. The engine’s crankshaft must be allowed to continue to spin while the driveshaft is stationary. A torque converter allows the engine and transmission to rotate independently of one another.

1.How To Tell If Torque Converter Is Locking Up - Auto …

Url:https://autocareaids.com/torque-converter-locking-up/

36 hours ago  · Simply put, a lockup converter is a type of torque converter that contains a clutch. The clutch automatically engages at some point during acceleration to “lockup” the engine to the transmission input shaft to deliver a direct 1:1 drive ratio.

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Url:https://www.bowlertransmissions.com/getting-locked-up-why-the-torque-converter-lock-up-is-important/

14 hours ago  · If you’re unfamiliar with exactly what the torque converter lock up is or does, the easy answer is, the lock up clutch takes stress off the fluid coupling of the torque converter and it helps decrease the amount of heat being generated at higher cruising speeds. Converter lock up wasn’t really an issue until the overdrive came about.

3.What Is a Lockup Torque Converter? - Gearstar …

Url:https://gearstar.com/what-is-lockup-torque-converter/

18 hours ago  · Most times, torque converters will lock and unlock without any particular reason. This means converters can lock and unlock automatically. Torque converters can lock up mainly due to acceleration and deceleration. Stay calm and take your car to the professionals if you suspect a locked up converter.

4.What are Lock Up Torque Converters? - YouTube

Url:https://www.youtube.com/watch?v=7xNkxw0R_68

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29 hours ago  · Well it's more of an issue of line pressure.. the line pressure for both 3rd and 4th gear is calculated for a locked converter. now adding a non lock up converter there MIGHT not be enough TV pressure to handle the added Torque, so the both OD and 3rd might slip.. and since they are both part of the lockup BOTH sets of clutches and bands are prone to the same exact …

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