2020 FORD F-350 Power Train Problems

Driving the vehicle at highway speeds (around 55mph). Driver hear a loud hum, lost power and needed to pull over. The rear axle housing grenaded and twisted the pinion clean off the rear axle. The truck was loaded with tools and pulling a trailer. However this load was well within the GVWR of the vehicle

I own a 2020 Ford F-350 Super Duty (VIN: [XXX] , mileage: ~20,000). The vehicle is subject to a recall involving the transmission output planetary four assembly replacement. Ford and the dealer insist that the transmission must be disassembled and rebuilt to complete this recall. I do not agree with this solution because it permanently alters the integrity of the original transmission. Additionally, the dealer (Route 23 Auto Mall, Butler NJ) has repeatedly mishandled repairs, including installing the fuel filter incorrectly multiple times. I have opened several case numbers with Ford Customer Service: Recall Case No: [XXX](02/02/2024) Fuel filter dealer error: [XXX] (01/06/2025), [XXX] (01/15/2025), [XXX] (08/26/2025) Transmission recall follow-up: [XXX] (02/25/2025) Buyback case (denied): [XXX] (03/04/2025) Despite multiple cases, Ford refused to buy back the vehicle because it is registered under a company name. This is unfair and leaves me with a defective and unsafe vehicle. I request NHTSA...

Transmission jerking hard down shift cause stalling Did update less then 100k miles on truck and now back doing it again

Our 2020 Ford F-350 experienced a catastrophic mechanical failure while in motion. The driveline disconnected, the rear axle locked up, and the transmission bellhousing was destroyed—leaving the truck completely immobile and blocking traffic. This occurred with no prior warning and posed a significant crash risk. At the time, Ford Safety Recall 22S22 (related to a known defect in the transmission’s output planetary four assembly) was open and had not yet been completed. The symptoms and failure we experienced match the failure scenario described in Ford's own bulletin for 22S22: driveline separation, internal transmission damage, and loss of control or Park function. Ford has denied coverage, stating the failure was due to a "loose pinion flange nut" and unrelated to the recall. However, they have not provided any inspection documentation, photos, or evidence that the recalled components were properly inspected or ruled out as the root cause. We have repeatedly requested...

My 2022 F350 transmission went in and out of gear driving down the high way It would slam in gear and cause a u. Safe driving condition . The dealer wants to rebuild it for the second time in two years or 40,000 miles sad the ten speed had issues Ford does not really want to help Thank you [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 Ford F-350. The contact stated while driving at an undisclosed speed, the vehicle hesitated and jerked while depressing the accelerator pedal. There was no warning light illuminated. The vehicle was taken to a dealer where a diagnostic test was performed. The contact was informed that an unknown part inside the transmission was defective, and that the transmission needed to be replaced. The vehicle remained in the dealer's possession and had yet to be repaired. The manufacturer was notified of the failure but offered no assistance. The contact was referred to the NHTSA Hotline to file a safety complaint. The failure mileage was approximately 120,000.

Transmission lunges forward or reverse when placed into gear from park. Transmission fails to shift or hard shifts while moving through low range. Shifting is soft or prolonged in some higher range with a noticeable lag.

The contact owns a 2020 Ford F-350. The contact received notifications of NHTSA Campaign Numbers: 21V536000 (Power Train) and 24V957000 (Fuel System, Diesel); however, the parts to do the recall repair were unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect for NHTSA Campaign Number: 21V536000 (Power Train). VIN tool confirms parts not available for NHTSA Campaign Number: 24V957000 (Fuel System, Diesel).

CDF cylinder failure in transmission leading to multiple hard shifts that could cause loss of traction and slick roads.

The transmission slips and hard shifts. I honestly believe the dealership knew and sold it to us knowing since we found out afterwards it's a known issue and in the bulletin about the truck.

The contact owns a 2020 Ford F-350. The contact stated while driving at an undisclosed speed, the vehicle shifted abnormally hard from first gear to second gear and from second gear to third gear. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The contact was informed that the dealer had found metal shavings in the transmission oil. The vehicle was not repaired. After investigating the failure, the contact related the failure to Customer Satisfaction Program: 21B03. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was unknown.

The contact owns a 2020 Ford F-350. The contact stated while placing the vehicle in park (P), he observed that the vehicle was rolling back. Additionally, the vehicle was shifting to a lower gear unintentionally. The contact stated no warning light was illuminated. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed and was not repaired. The contact had researched online and related the failure to NHTSA Campaign Number: 22V256000 (Power Train) The manufacturer was informed of the failure but had advised the contact that his VIN was not part of the vehicle VIN selection. The failure mileage was approximately 69,500.

My 2020 Ford F-350 has had an occasional problem with the transmission since shortly after I purchased it. It started with sticking in gear occasionally to the point where the engine RPM's would stay very high but not shift even when pushing the accelerator even more. It just would not come out of it. The dealer didn't find any issue and the issue subsided a bit, but in the last 6-8 months, it has noticeably shifted hard into drive, but not when shifting into reverse. Putting it in drive even with the brake depressed hard to the floor, it jolts forward and shakes the entire truck. When downshifting, it sometimes does it so hard that it feels like a vehicle hit the rear of the truck. There is nothing smooth about this truck with the behavior this transmission is showing. I changed the fluid and filter 6 weeks ago and...

The contact owns a 2020 Ford F-350. The contact received notification of NHTSA Campaign Number: 21V536000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer and a secondary dealer, Galpin Ford (15505 Roscoe Blvd, North Hills, CA 91343); were contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

I HAVE BEEN EXPERIENCING ISSUES WITH MY TRANSMISSION. I TOOK THE TRUCK TO THE FORD DEALERSHIP IN POTEAU, OKLAHOMA. I WAS INFORMED THE VEHICLE WAS HAVING THE SAME ISSUES AS THE TRANSMISSIONS THAT WERE ON A RECALL LIST, YET MY VIN NUMBER WAS NOT ONE ON THE LIST. I DID RECEIVE A RECALL NOTICE FROM FORD IN 2022 TIMEFRAME, BUT WAS NOT HAVING ISSUES AT THE TIME I RECEIVE THE NOTICE. ON AUGUST 15, 2024, I CONTACTED FORD HEADQUARTERS AND WAS TOLD... "YOUR VEHICLE DOES INDEED FIT THE CRITERIA OF THE AFFECTED VEHICLES, BUT YOUR VIN NUMBER IS NOT ON THE LIST OF THE AFFECTED VEHICLES. WE CANNOT TELL YOU WHY YOUR VEHICLE IS NOT ON THAT LIST, BUT I WOULD SUGGESTED THAT YOU CONTACT (NHTSA) AND ASK FOR YOUR VIN BE ADDED TO THE LIST. I RECOMMEND YOU DO THAT AS SOON AS WE HANG UP." THE MOMENT I...

The contact owned a 2020 Ford F-350. The contact stated that while driving at 45 MPH, towing a boat he heard a loud popping noise. The contact stated that the rear wheels were locked in place, and skid. The vehicle whiplashed and the right side of the vehicle collided with the guard rail and came to a stop and inspected. The contact observed condensation under the middle and rear of the vehicle and the drive shaft lying on the ground. A police report was filed and no injuries were reported. No medical attention was needed. The vehicle was towed to a lot where it was deemed totaled. The manufacturer was notified of the failure. The failure mileage was approximately 45,000.

The contact owns a 2020 Ford F-350. The contact stated while driving at an undisclosed speed, the transmission failed to operate as needed. The contact stated that when the brake pedal was depressed, the transmission shifted excessively hard. The vehicle had previously been taken to the dealer however, the failure could not be duplicated. Additionally, the contact stated that the check engine warning light illuminated prior to the vehicle becoming undriveable. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 60,000.

The contact owns a 2020 Ford F-350. The contact stated that while driving at various speed, the transmission was slipping while downshifting and upshifting. The contact also stated that there was a hard shift, and the vehicle would lose motive power and lunge forward. The wrench warning light was illuminated. The contact stated that a dealer representative went to the residence to perform a software update however, the failure persisted, and the vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 113,000.

The contact owns a 2020 Ford F-350. The contact stated while driving 55 MPH, the vehicle unintendedly downshifted and the vehicle lost motive power. After the failure, the vehicle went into LIMP Mode and stalled. The contact stated that the check engine warning light was illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The vehicle was not repaired. After investigating the failure, the contact related the failure to Customer Satisfaction Program 21B03. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 75,000.

The transmission 10R140 skip, jumps and hesitation when driving in any gear. The transmission jumps forward when backing up with out of control Function and driver un able to control vehicle. There was a safety recall on this transmission on the 10R140 with the 6.7 diesel truck. My truck is a 6.2 liter gas engine with the same Transmission 10R140 built in the same plant and same time frame as the safety recall 22S22 as stated in this letter attached. My transmission has failed and is a safety problem as addressed in this letter

*Component or system: the transmission (10R140) on my F350 Truck has failed. The transmission has been inspected by a Ford service tech shop at dealership. * The truck would jump gear and jump or jolt when backing up., slight pause in power when driving truck at any speed. * The truck is at a Ford Dealership at this time. The service tech said this transmission needs to be replaced, it is unsafe to drive. The truck was bought brand new and only has 73,000 miles *The truck has been inspected by a Ford service tech for the transmission *The problem was happening on & off at times, but recently a warning lite came on 10/29/2023 which would come on & off at times I see that there was a safety recall 22S22 on this transmission 10R140 for super duty trucks built in 2020. The letter from Ford written by David...

The contact owns a 2020 Ford F-350. The contact stated while driving 60-65 MPH, the transmission was slipping and unintendedly downshifting. The contact stated that upon driving from a complete stop, the vehicle stalled with the transmission stuck in 10th gear, nearly causing a crash. The contact stated that the vehicle responded as needed upon depressing the accelerator pedal a second time. The contact stated that the failure recurred while driving. The power train malfunction warning light was illuminated. The vehicle was taken to the dealer, who informed the contact that the earliest appointment for a diagnostic test would be approximately 6 weeks. The vehicle was not diagnosed nor repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 25,500.

The contact owns a 2020 Ford F-350. The contact stated that while driving at approximately 65 MH, the transmission was slipping while downshifting and upshifting. The contact also stated that after starting the vehicle, the transmission seized after shifting into 4th gear, with the powertrain malfunction warning light illuminated. The contact stated that the vehicle was inoperable. The vehicle had not yet been taken to an independent mechanic or a local dealer. The contact became aware of Customer Satisfaction Program: 21B03 (Transmission - Number One Planetary and Ring Gear Assembly); however, the VIN was not included. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The approximate failure mileage was 109,000.

The contact owns a 2020 Ford F-350. The contact stated that when the transmission lever was shifted into reverse, the vehicle inadvertently shifted into drive. The brake pedal was immediately depressed, and the vehicle stopped. Additionally, the transmission warning light was illuminated prior to the failure. The contact stated that the internal code was reset a several times. The vehicle was taken to an independent mechanic and the contact stated that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 87,000.

My transmission is experiencing a grinding and groaning noise and has occasional harsh shifting. I took it to the dealer and they are saying it’s not part of the recall.

The contact owns a 2020 Ford F-350. The contact stated that while driving at various speeds, the transmission was shifting hard between gears. No warning lights were illuminated. The vehicle was previously serviced at a local dealer under Ford Customer Satisfaction Program: 21B03 to replace the No. 1 planetary and ring gear assembly. The vehicle was repaired; however, the contact stated that the failure persisted, and that the vehicle was jerking while shifting between gears. The contact had received notification of NHTSA Campaign Number: 22V256000 (Power Train) and 22V644000 (Back Over Prevention); however, the parts to do the recall repair were unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was contacted and confirmed that parts were not yet available. The manufacturer was contacted and was unable to confirm when parts would be available. The contact was advised to...

The contact owns a 2020 Ford F-350. The contact stated that while the transmission was shifted into park(P), the vehicle rolled back and crashed into another vehicle. There were no injuries. A police report was not filed. The vehicle was taken to the dealer; however, the mechanic was unable to duplicate the failure. The contact received notification of NHTSA Campaign Number: 22V256000 (Power Train) however, the part to do the recall repair was not yet available. The manufacturer was made aware of the failure. The approximate failure mileage was 5,000. VIN tool confirms parts not available.

The contact owns a 2020 Ford F-350. The contact stated that after starting the vehicle, there was a loss of power steering, and the vehicle lost motive power. The vehicle failed to restart. No warning lights were illuminated. The contact used an OBD scanner to retrieve failure codes for the powertrain control module (PCM) and the engine control module (ECM module). The vehicle was towed to an independent mechanic, where it was diagnosed that the fuse box and wiring harness needed to be replaced. The vehicle remained with the independent mechanic awaiting the repair. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The approximate failure mileage was 164,000.

The contact owns a 2020 Ford F-350 The contact received notification of NHTSA Campaign Number: 22V256000 (Power Train) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated the vehicle was starting to display hard shifting. The check engine warning light was illuminated, and the wrench light was illuminated intermittently. The manufacturer was made aware of the failure. The approximate failure mileage was 89,000. VIN tool confirms parts not available.

The contact owns a fleet of 2020 Ford F-250. The contact's employees had informed him that while driving at various speeds and shifting between gears, the vehicles were jerking as the check engine warning light was illuminated. The failure recurred on various occasions, and the contact's employee also stated that while driving at an undisclosed speed, the brakes were applied and failed to respond so the gear was shifted into neutral(N) and he had to depress the brake pedal with excessive force in order for them to respond and avoid almost hitting another vehicle. The contact called various local dealers and made them aware of the failure; however, there was no availability or capacity for the fleet vehicles. The vehicles were not yet diagnosed or repaired by an independent mechanic or local dealer. The manufacturer was not made aware of the failure. The approximate failure mileage was 25,000.

The contact owns a 2020 Ford F-350. The contact stated that while driving at various speeds, the vehicle would hesitate and enter into Limp Mode upon depression of the accelerator pedal. The contact stated the wrench warning light had appeared on the instrument panel. The contact called the dealer and was informed that his vehicle was not under recall. The manufacturer was notified of the failure and was given a case number. The vehicle was not diagnosed or repaired. The failure mileage was approximately 130,000.

The contact owns a 2020 Ford F-350, The contact stated that after the vehicle had been turned off for an extended period, after restarting the vehicle, the vehicle would not immediately drive forward or in reverse; however, the vehicle would roll if on an inclined surface. The vehicle was taken to the dealer who diagnosed that the condition was caused by transmission fluid draining back from the torque converter. The contact was informed that manufacturer was aware of the condition and had advised that no service be performed to resolve the issue; but owners should be advised in order to prevent the condition from occurring, to allow the engine to run for a while before attempting to drive. The manufacturer was contacted and advised the contact that no service would be performed to correct the condition. The contact was concerned that in an emergency situation the vehicle could not immediately...

The contact owns a 2020 Ford F-350. The contact stated while driving 30 MPH, the accelerator pedal was depressed; however, the vehicle failed to exceed 30 MPH. There was no warning light illuminated. The contact was able to continue driving. The vehicle was taken to the dealer where it was diagnosed and determined that the transmission needed to be replaced. The manufacturer was notified of the failure and a case was opened. The manufacturer then followed up with the dealer and was informed that the failure was not associated with NHTSA Campaign Number: 22V256000 (Power Train) even though the VIN was included. The manufacturer closed the case and referred the contact to the NHTSA. The dealer informed the contact that she would be responsible for the cost of the repair. The vehicle was not repaired. The failure mileage was approximately 130,000.

Brand new 2020 F350 started having issues around 62,000 miles....we have reported these issues to Ford in Harriman and Ford in Lenoir (They do not have a transmission specialist available in Lenoir and Ford in Harriman states they don't honor my extended warranty that we purchased through Ford). In January we started having issues when we were traveling on the interstate heading towards Chattanooga. Which is only about 45 minutes to an hour away. The wrench light came on and the truck started to shift hard and at a high RPM , getting stuck in 7th gear not wanting to shift between 3rd and 4th gear. The truck started to go into limp mode and we managed to get it home and bring it to Ford in Harriman (Jerry Duncan Ford). They stated the TCM needed to be reset, and proceeded with that costing $165. Three weeks later, my truck...

The contact owns a 2020 Ford F-350. The contact stated that while attempting to reverse the vehicle, the engine revved but the vehicle would not move. The power train malfunction warning light illuminated. The vehicle was taken to the dealer and diagnosed with number one planetary and ring gear assembly failure. The number one planetary and ring gear assembly needed to be replaced. The vehicle was not repaired. Upon investigation, the contact related the failure to Customer Satisfaction Program: 21B03 (Number One Planetary and Ring Gear Assembly) however, the dealer informed the contact that the VIN was not included in the program. The manufacturer was made aware of the failure and referred the contact to file a complaint with NHTSA. The failure mileage was approximately 163,000.

The contact owns a 2020 Ford F-350. The contact received notification of NHTSA Campaign Number: 21V536000 (Power Train). The contact took the vehicle to local dealer but was not able to complete the recall due to not having and employee to weld the axle. The contact was not content with welding the axle. The manufacturer was made aware of the issue. The contact had not experienced a failure.

The contact owns a 2020 Ford F-350. The contact stated that the vehicle was hard to shift. The vehicle lunged forward about a foot. While driving, the vehicle skipped 4th, 5th, and 7th gear. The vehicle shutdown and went into limp mode. The power train message was displayed. The vehicle was taken to the local dealer and diagnosed with the PCM needing to be reprogrammed. The vehicle was repaired however, the failure recurred. The vehicle was taken to another local dealer - Cole Ford LLC (410 E Chicago St, Coldwater, MI 49036, (517) 278-5661) and diagnosed that the vehicle was working as designed. The manufacturer was notified however, no further assistance was provided. The approximate failure mileage was 5,000.

The contact owns a 2020 Ford F-350. The contact stated while driving at various speeds, the transmission experienced rough shifting and the maintenance warning light was displayed. The transmission later became stuck in 7th and 3rd gears and the vehicle went into limp mode reducing the speed to 35 mph. The vehicle was driven to the local dealer, but the cause of the failure was not yet determined. The manufacturer was notified of the failure. The failure mileage was 152,000.

I PURCHASED THIS TRUCK ON 09/23/20. AT DELIVERY THE STEERING WHEEL WAS NOT ALIGNED CORRECTLY AND HAD TO BE ADJUSTED. TRUCK HAS HAD A CONSTANT VIBRATION THAT IS FELT THRU THE STEERING AND BODY. THE VIBRATION INCREASES WITH SPEED. AT 1031 MILES A REPAIR ATTEMPT WAS MADE THAT WAS UNSUCCESSFUL, AT 3225 MILES AGAIN A FAILED ATTEMPT WAS MADE AT CORRECTING, AT 3735 ANOTHER FILED ATTEMPT. AT 8156 ANOTHER FAILED ATTEMPT. AND AGAIN AT 8934 ANOTHER MORE EXTENSIVE REPAIR ATTEMPT WAS MADE WITH NO POSITIVE RESULTS. I WILL UPLOAD ALL REPAIR WORK ORDERS. THERE IS A SERIOUS PROBLEM IN THE DRIVETRAIN OF THE VEHICLE THAT FORD AS OF YET HAS BEEN UNABLE TO CORRECT. THE VIBRATION IS CONSTANT AND AT HIGHWAY SPEED HAS MADE PEOPLE CAR SICK. I AM FEARFUL THAT THERE IS A FAILING COMPONENT IN THE TRUCK THAT WHEN IT FINALLY BREAKS WILL CAUSE A SERIOUS ACCIDENT. THEY...

ON 3 OCCASIONS SINCE I BOUGHT THE PU NEW ON JULY 24TH, 2020 I EXPERIENCED WHAT THE FORD DEALER NOW CALLS DEATH WOBBLE. THE FIRST TIME HAPPENED ON SEPT 2ND WHILE DRIVING DOWN HILL PULLING MY TRAILER AT ABOUT 50MPH. WHEN I STEPPED ON THE BRAKE THE STEERING WHEEL AND BRAKE PEDAL STARTED TO SHAKE VIOLENTLY. I HAD LITTLE CONTROL UNTIL MY SPEED DROPPED. I TOOK THE PU TO THE DEALER SEPT 16TH. THEY SAID THEY COULD FIND NO PROBLEM AND STATED IF THEIR AGENT COULD NOT EXPERIENCE THE PROBLEM WHILE DRIVING THE PU THEY COULD NOT FIX IT. ON THE SECOND TIME I WAS DRIVING THE PU EMPTY AT HIGHWAY SPEED AND AGAIN WHILE BRAKING THE STEERING AND BRAKES SHOOK VIOLENTLY. UP TO THIS POINT I WAS THINKING THE BRAKES WERE THE PROBLEM. I STARTED TRACKING THE BRAKE TEMPERATURE WHICH SHOWED A LARGE VARIETY OF TEMPS FOR SIMILAR DRIVING...

TL* THE CONTACT OWNS A 2020 FORD F-350. THE CONTACT STATED THAT THE TRANSMISSION AND TORQUE CONVERTER WERE REPLACED FIVE TIMES WITHIN THE LAST 9,000 MILES. THE VEHICLE WAS TAKEN TO CARUSO FORD LINCOLN (3500 CHERRY AVE, LONG BEACH, CA 90807; (562) 426-3301) WHERE ALL THE REPAIRS WERE MADE HOWEVER, THE FAILURE PERSISTED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND A CASE WAS FILED. THE APPROXIMATE FAILURE MILEAGE WAS 37,000.

THE SAME PROBLEM AS THE RECALL IS 20S33. TORGUE CONVERTER DAMPER FRACTURE. THE TRUCK WAS SOLD WITH TECHNICAL PROBLEMS OF THE BACKUP CAMERA, THAT TOTALLY DOESN’T WORK TILL NOW. THE BIGGEST PROBLEMS STARTS ON 07 TH OF OCTOBER 2020, WHEN I NOTICED A HUGE NOISE IN THE CAR ACCORDING TO THE TRANSMISSION SYSTEM. ON THE 08 TH OF OCTOBER 2020, I HAVE BEEN TO DEALERSHIP LOCATED AT 8445 45 TH ST LYONS, IL, 60534, AND I LEFT THE CAR AT THEIR SERVICE CENTER TO DIAGNOSE THE TECHNICAL PROBLEM AND FOR SURE TO SOLVE IT. DURING ONE WEEK THEY CAN’T DIAGNOSE THE PROBLEM. AFTER THAT, THEY CALLED ME, AND SAID THAT THE PROBLEM WAS DIAGNOSED BUT UNFORTUNATELY THEY DIDN’T HAVE THE NECESSARY SPARE PARTS, BECAUSE THE FORD MOTOR COMPANY DOESN’T PRODUCE MORE THIS KIND OF SPARE PARTS. BUT HOW IT’S POSSIBLE TO SELL THE CARS WITHOUT NECESSARIES SPARE PARTS, WHAT HAVE...

WHILE NEGOTIATING STEEP GRADES (OVER 8 DEGREES) AT MODERATE SPEEDS (~30MPH) WITH THE ENGINE BRAKE IN AUTOMATIC A 3RD GEAR TO 2ND GEAR OR 2ND GEAR TO FIRST GEAR CHANGE IS PROCEEDED BY A SIGNIFICANT ACCELERATION BY AS MUCH AS 5MPH OR MORE THIS CAN BE SIMULATED ON LESS STEEP INCLINES BY ENGAGING THE ENGINE BRAKE AND MANUALLY SHIFTING FROM 3RD TO 2ND.. THERE WILL BE AN INCREASE IN SPEED THAT CAN BE QUITE SIGNIFICANT THERE IS A MINOR REDUCTION IN BRAKING WHEN THE TRUCK PERFORMS A 4TH TO 3RD DOWNSHIFT BUT IT DOESN'T CAUSE ACCELERATION TO THE DEGREE THAT THE 3RD AND 2ND SHIFTS DO. THE CIRCUMSTANCES UNDER WHICH AN ENGINE BRAKE WOULD BE USED ARE EXACTLY THOSE CIRCUMSTANCES WHERE AN UNINTENDED ACCELERATION OF ANY KIND IS MOST DANGEROUS, SUCH AS MOUNTAIN ROADS AND SWITCHBACKS WHILE TOWING HEAVY LOADS THE DEALER IS AWARE OF HOW TO REPRODUCE THIS EVENT...

SHIFTING FROM 2 TO 3RD GEAR WHILE LIGHTLY ACCELERATING, IT BANGS SO HARD I THINK TRANSMISSION FELL OUT. IF IT UNDER AGGRESSIVE ACCELERATION, IT'S SMOOTH