Transmission shudder

Sometimes when I try to accelerate when driving my Ford I feel a shudder even if I'm going slow. What does it mean?

My car has 98756 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi There,
It sounds like your vehicle may be a bit low on transmission fluid or you may potentially have a bad transmission control solenoid. As you know, the transmission works on hydraulic pressure built up from the fluid inside and uses this pressure to activate solenoids that cause the transmission to shift. When these are not working properly or when you have low transmission fluid, this does not happen which usually results in erratic shifting patterns, or in some cases no shifting at all. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Worn Or Damaged Torque Converter

One of the most common causes of a Ford Focus`s transmission problem is simply having a worn or damaged torque converter. Otherwise called torque converter or hydraulic system, this component transmits torque from a car`s engine to a rotating driven load.

Have any transmission shudder recalls been issued for the 2014 Ford Focus? As of August of 2020, there`s no recalls concerning the transmission.
The transmission is the most common problem with used 2012 Ford Focus models, with owners reporting shuddering and jerking when changing gears.
This condition may be caused by small stones, road debris, ice or snow packed/lodged in the rear engine roll restrictor. Inspect the rear engine roll restrictor for debris and install a service shield if necessary.
Many possible faults can cause your 2013 Ford Focus to vibrate upon acceleration. From your description, it sounds like you are describing an engine misfire. Misfires can be caused by many issues, but the most common are spark plugs, coil, fuel pump, fuel injectors, MAF sensor, vacuum leaks, or a wiring harness fault.
Ford Motor Company (Ford) is recalling certain model year 2012-2014 Focus Electric vehicles manufactured September 15, 2011, through August 23, 2013. In the affected vehicles, a powertrain control module software problem may result in a stall-like condition.
These transmission defects have resulted in thousands of lawsuits against Ford across the United States. Today, in California alone, there are at least 800 current individual lawsuits against Ford Motor Company for issues with the PowerShift Transmissions on the 2011-2015 Ford Fiesta and 2012-2015 Ford Focus.
How To Fix a Shuddering Transmission. Fortunately, fixing a shuddering transmission is often as simple as getting a transmission flush to replace the contaminated transmission fluid with clean, fresh fluid.
To put it briefly, no you should never drive your vehicle if you believe there to be an issue with your transmission in any case. Once a transmission starts slipping it needs to immediately be repaired. Every time you drive it after you feel your transmission slip, it is a risk.
All 2012 Focus models use an all-new 2.0-liter engine with direct injection and twin variable valve timing. A 5-speed manual transmission is standard, 6-speed automatic optional, with SelectShift manual mode an option to the optional transmission.
An indication that a vehicle is not receiving the right mixture of air and fuel is if the vehicle jerks or surges forward at high speed. Several components of the fuel or air intake system could cause this jerking or surging sensation to happen. Issues within these systems can also cause fuel economy to worsen.
Automatic transmissions that shift hard, jerk or shake during a shift change may mean your transmission fluid needs changed or fluid level is low. In manual transmission vehicles, abnormal gear shifts could indicate damaged gear synchros, worn clutches or other, more severe issues.
Any unusual shaking or vibrating forces coming from the engine is cause for concern. It could be something as simple as old spark plugs producing an uneven power delivery, it could be something serious like worn or broken engine mounts, or it could be even more serious in the case of internal engine damage.
One of the most noticeable symptoms of torque converter shudder is vibrations or shaking while driving. These vibrations can be felt through the steering wheel, floorboard, or seat of the vehicle. The severity of the vibrations may vary depending on the extent of the shudder and the speed of the vehicle.
One common cause of shaking while idling can be loose engine mounts. Engine mounts are the connections between your engine and your car — they keep your motor safely attached while dampening vibrations produced by your engine. When those connections wear out, you`re more likely to feel the vibrations.
There are a range of reasons why your car is juddering when you accelerate. Your vehicle could have dirty fuel injectors, a damaged fuel pump, a blocked catalytic converter, a faulty mass airflow sensor, broken spark plugs, or even an accumulation of moisture.
However, the primary cause of a shuddering transmission is simply contaminated transmission fluid. When the fluid in a transmission becomes dirty and contaminated, the particles in the fluid prevent it from building up enough pressure in the transmission lines.
There are a range of reasons why your car is juddering when you accelerate. Your vehicle could have dirty fuel injectors, a damaged fuel pump, a blocked catalytic converter, a faulty mass airflow sensor, broken spark plugs, or even an accumulation of moisture.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

There is automatic transmission fluid in a manual transmission. Is it okay to leave or do I need manual transmission fluid?
ANSWER : This would depend on what the manufacturer recommends. Many manual transmissions do take automatic transmission fluid. If your transmission has ATF in it, it is very likely that it is supposed to have that in there. If not, it is likely that the transmission would not function properly with the wrong fluid. Many manual transmissions will also take engine oil as a lubricant. The best way to know for sure is to check your owner’s manual or call your local General Motors dealership to inquire.

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2013 Ford Focus Transmission Issue. Is it worth keeping the car?
ANSWER : Hi There,
This is a known issue in this generation Ford Focus and some Fiestas with the "Power Shift" transmission and there have been numerous recalls and lawsuits. Although, it is would be difficult to determine how much longer your transmission will last given the fact that you have many new parts, I would not recommend junking the car as it may still provide some valuable life left for you. I would recommend taking it to the dealer to see if these parts may be covered under the recall.

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Transmission fluid comes up out of the transmission vent tube attached to the transmission dipstick tube
ANSWER : Hi there. Fluid seepage out of the vent tube can sometimes be normal, but can also be caused by overfilling. Has a service been performed recently? Perform a fluid level and condition inspection by having the engine at idle, on a level surface, warmed up engine, and remove the dipstick and cleaning it with a shop towel. Reinsert the dipstick and fully remove to a horizontal position for inspection. Make sure the fluid is not milky, very dark, or has contamination. The level should be in the safe zone marked on the stick.

Have an inspection by a qualified technician determine if any problems truly do exist and provide you with some assurance. YourMechanic has several technicians available that can assist you with a transmission leak inspection and can perform a transmission fluid service if needed.

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Kia Optima 2004 v6 LX new engine old transmission no problems before with transmission now my transmission is shifting a high rpm
ANSWER : Hi There,
This may be an issue related to the communication of the PCM and the TCM (Transmission control module). As you may know, the TCM relies on the PCM to transmit information related to RPM’s, which the TCM then uses to determine when to direct the transmission to shift. The transmission control module has various sensors such as vehicle speed sensors, wheel speed sensors, throttle position sensors, turbine speed sensor, and transmission fluid temperature sensors that all direct information to it in order for it to perform it’s function. Other functions controlled by the TCM are components such as a kick down switch, traction control system, and cruise control module. Any of these may also affect the way the transmission control module performs and controls the transmission and the shifting of your vehicle. I would suggest having a professional from Your Mechanic come to your location to properly diagnose your transmission problem.

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Can too much transmission fluid cause speedometer malfunctions?
ANSWER : Hi there. In most cases when you overfill the transmission fluid it can cause excessive foaming of the fluid or possible internal component failure due to excessive pressure inside the hydraulic lines. Sensors like the speed sensors however are rarely impacted by this situation. However, in regards to the possibility of probability of this; I would say perhaps a 10% chance.

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Everytime I put car into gear it shuts off the car but idles fine
ANSWER : This sounds like a faulty speed sensor problem. Most cars have two speed sensors (one monitors input shaft and one monitors output shaft) which tell the computer what the gear ratio is of the transmission while in use. If either of these are not working properly, they will cause the computer to shut the car off for safety reasons. I would suggest having an expert from YourMechanic come to your home to diagnose your stalling issuee and help you repair it.

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Can I add Lucas oil "transmission fix" to my transmission fluid to see if it helps my issue.
ANSWER : Adding an additive to the transmission to try and fix a problem will not work in most instances and should only be used as a last resort before getting a transmission overhaul.

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Bought a 1999 Chevy Z71 for very cheap. The transmission is out. How should this be fixed?
ANSWER : Hi there. The 4l60e transmission could have two things wrong with it. Either the park arm is not disengaging inside the transmission making the transmission load up but not rotate the drive shaft or the transmission is low on oil. Check the oil on the transmission dip stick and see what the level is. The level must be checked with the engine running. If the oil level is at the full mark, then it is possible that the torque converter may have damaged the pump.

Remove a cooler line and put it into a bucket, and for a brief moment start up the engine and shut it off. If oil sprays out of the cooler line, then the pump is producing pressure. However, if no oil comes out of the cool line, then the pump is not working.

If you need further assistance troubleshooting your transmission, then I recommend having the transmission problem diagnosed by a local expert, such as one from YourMechanic. You will be be able to make a better decision about the car after finding out exactly what’s wrong with it.

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