E350 Transmission Problems

Posted By admin On 27/11/21

The Mercedes-Benz E350 was offered as part of midsize E-Class series for many years, although 2014-2016 are the most recent. During this time, the E350 is characterized by a 3.5L V6 engine at 302 hp, a seven-speed automatic transmission, and rear-wheel drive. The Mercedes-Benz E350 is a comfortable, quiet and luxurious sedan, with a well-finished interior, comfortable seats and a substantial feel. Transmission, and brakes to power equipment and the.

Troubleshooting is the step-by step process where you can logically diagnose a problem. This involves a process of elimination, usually starting from the simple, easy-to-check items, then moving on to more difficult items in logical sequence.

This Tech Tip is From the Full Book, GM TURBO 350 TRANSMISSIONS: HOW TO REBUILD AND MODIFY. For a comprehensive guide on this entire subject you can visit this link:

SHARE THIS ARTICLE: Please feel free to share this article on Facebook, in Forums, or with any Clubs you participate in. You can copy and paste this link to share: https://www.chevydiy.com/gm-turbo-350-transmission-rebuild-troubleshooting-guide/

For example, if your transmission doesn’t move the vehicle at all when placed into service after an overhaul, you should check the transmission fluid level before pulling the transmission out to check the oil pump or torque converter.

The TH350 is a rugged and durable unit, and fairly simple in construction and operation as far as automatic transmissions are concerned. If you have correctly assembled the unit, and it passed the air checks to the clutch drums through the openings in the case during assembly, any issues should be relatively easy to diagnose and repair.

If you look at the list below, it quickly becomes evident that many problems can share a common cause, such as the transmission being low on fluid, or the gear shift selector not moving the manual valve correctly.

The TH350 has one advantage over a TH400 in that the filter is attached to the bottom of the valve body and already on the bottom of the oil pan. This eliminates the potential for a leak at the suction tube or O-ring in the case. This still doesn’t mean that the filter can’t plug up and cause issues, but at least you don’t have to worry about an air leak on the suction side of the oil pump because you forgot to install an O-ring or missed a crack in the suction tube.

The most difficult problems when it comes to transmission function involve the valve body (control valve assembly). In almost all cases the valve body must be removed to correct any issues, and this should be done after all other possibilities have been eliminated. The good news as it relates to valve body problems is that the TH350 uses a cast-iron valve body with steel valves, making it rugged and nearly unaffected by over tightening fasteners.

Small pieces of dirt or debris are the enemy of the automatic transmission as it is a close-tolerance hydraulic system with quite a few moving parts. In many cases involving poor performance, sticking valves, and/ or erratic shifting, you will find that some sort of contamination has gotten into the control valve assembly and restricted proper fluid flow.

In any case, when troubleshooting the TH350, as with most other mechanical devices, start with the most simple and accessible things first, then move on to more difficult-to-inspect/repair items.

Remembering my own experience with TH350s that suddenly quit up shifting correctly, or not at all, the cause has been loss of vacuum to the vacuum modulator, or broken teeth on the governor, both of which are relatively easy to diagnose and repair.

The following is a list of symptoms and their potential causes.

Vehicle Slips in Park

  1. Parking pawl guide damaged or incorrectly installed
  2. Parking pawl broken, cracked, or worn smooth
  3. Broken teeth on output shaft ring gear 4. Manual linkage not properly adjusted

No Drive in any Range

  1. Manual control linkage out of adjustment or manual valve S-link disconnected from lever
  2. Low oil level, blocked oil filter
  3. Low oil pressure, pressure regulator valve stuck, damaged or fell out of valve body
  4. Damaged oil pump drive gear or torque converter hub
  5. Defective torque converter
  6. Forward clutch damaged or not applying
  7. Roller clutch assembly broken or damaged 8. Broken input shaft

No Drive with Range Selector in “D”

  1. Manual linkage out of adjustment
  2. Low oil level
  3. Low oil pressure or blocked oil filter
  4. Forward clutch pack no applying, forward clutch pack frictions burned up
  5. Roller clutch missing, damaged, or not holding

No 1-2 Shift

  1. Governor valve stuck, governor filter plugged
  2. Damaged governor gear or damaged governor bore in case
  3. Detent cable binding
  4. 1-2 shift valve assembly stuck or incorrect valve body gaskets
  5. Intermediate clutch incorrectly assembled or not holding, air check circuit
  6. Intermediate roller clutch broken, not holding, or sprag-type clutch incorrectly installed

1-2 Shift at Full Throttle Only

  1. Detent valve assembly stuck or incorrectly installed in valve body
  2. Detent cable stuck or out of adjustment
  3. No vacuum-to-vacuum modulator or stuck/sticking modulator or modulator valve

1st and 2nd Shift only, No 2-3 Shift

  1. Control valve 2-3 shift stuck
  2. Valve body gaskets leaking, damaged, or incorrectly installed
  3. Sealing rings on pump hub damaged or missing
  4. Direct clutch seals missing or damaged

No Reverse

  1. Low oil level
  2. Check manual control linkage
  3. Filter plugged
  4. Modulator valve stuck
  5. Direct sealing rings on pump hub broken or missing
  6. Low/reverse clutch piston seals cut or missing
  7. Number-1 check ball missing
  8. 1-2 or 2-3 valvetrain stuck
  9. Intermediate servo piston or pin stuck so that band is applied
  10. 10.Direct clutch plates burned

Slips in All Ranges

  1. Low oil level
  2. High oil level and oil foamed
  3. Vacuum modulator valve defective or sticking
  4. Filter assembly plugged
  5. Valve body gaskets misaligned or wrong gaskets
  6. Pressure regulator valve stuck
  7. Pump to case gasket damaged
  8. Forward clutch slipping

Slips on 1-2 Shift

  1. Low is incorrect oil level
  2. Sticking modulator valve or defective modulator
  3. Pressure regulator valve defective
  4. Out of position or incorrectly installed valve body gaskets
  5. Intermediate clutch seals damaged, reversed, or missing
  6. Damaged intermediate clutch plate
  7. Accumulator seals damaged or missing
  8. Damaged intermediate roller clutch or sprag type clutch installed backward
Ford e350 transmission problems

Slips on 2-3 Shift

  1. Items 1 to 4 under “Slips on 1-2 shift”
  2. Direct clutch plates burnt
  3. Damaged or missing oil sealing rings on pump hub
  4. Damaged or missing seals on direct clutch apply piston
  5. Damaged or missing 2-3 accumulator seals

Harsh 1-2 Shift

  1. Broken or damaged 1-2 accumulator piston
  2. Blocked 1-2 accumulator feed hole in valve body plate or blockage in passages to 1-2 accumulator

No 1-2 Shift, but Has 1-3 and 3-1

  1. Broken or not holding intermediate roller clutch
  2. Aftermarket 36-element clutch installed backward

No Engine Braking in Second

  1. Intermediate servo sealing rings damaged or missing
  2. Intermediate servo stuck on pin or in bore in case
  3. Accumulator rings broken, damaged accumulator bore, or accumulator piston stuck
  4. Intermediate overrun band damaged, burned, or broken
  5. Low oil pressure, pressure regulator valve stuck, boost valve stuck

No Engine Braking in Low

E350 Transmission Problems
  1. Manual low control valve assembly stuck
  2. Low oil pressure
  3. Pressure regulator and/or boost valve stuck
  4. Low/reverse piston seals damaged, broken, or missing

No Part Throttle Downshift

  1. Low oil pressure
  2. Vacuum modulator defective or modulator valve sticking
  3. Pressure regulator valvetrain assembly malfunctioning
  4. Detent valve stuck or sticking; detent cable damaged or sticking
  5. 2-3 shift valve stuck

Ford E350 Transmission

No Detent Downshifts

  1. 2-3 valve stuck
  2. Detent valve, linkage, or cable sticking, disconnected, damaged, or broken

2006 E350 Transmission Problems

Low- or High-Shift Points

  1. Low or high oil level
  2. Check vacuum at modulator and hoses in between modulator and carburetor/intake manifold
  3. Vacuum modulator defective
  4. Modulator valve stuck or sticking
  5. Pressure regulator valve stuck or sticking
  6. Governor assembly
  7. Restricted feed hole or blocked filter to governor
  8. Detent valve stuck open 9. 1-2 or 2-3 valvetrain sticking

Slow Engagement Cold

  1. Low oil pressure
  2. Piston seals old and no longer pliable; common problem for old units that need rebuilding

Noisy Transmission

  1. Noise from pump caused by high or low oil level
  2. Cavitation from plugged oil filter
  3. Water in oil
  4. Damaged oil pump gears and housing
  5. Worn or damaged planetary gears
  6. Burnt or worn clutch plates, or burnt lining on band

Written by Cliff Ruggles and Posted with Permission of CarTechBooks

E350 Transmission Problems


If you liked this article you will LOVE the full book. Click the button below and we will send you an exclusive deal on this book.

Rate this item

There is an information blackout on the subject yet piecing together the 'service information and measures' with our warranty data we can see that many defects of the sensors in the transmissions cause total gearbox failures while driving.

When transmission defects were not too common before 2005, the Mereceds Benz 6 speed gearboxes used to go into a true 'limp home mode' where the driver could never shift the gear beyond first gear till the failed internal sensor or mechanical defect was addressed in a workshop.

With the introduction of the most defective transmission (722.69 7-gtronic) it became obvious that the sensor failure had become an everyday occurrence. To date it is hard to keep track of how many replacement part numbers have been introduced and the instructions have also changed so often that it raises the obvious question of doing R & D on customer’s cars behind their backs at the risk of their death.

Please take the time to Google the terms 722.9, defective, sensors, ESP etc. to get a favour of the depth of customers anguish worldwide to this abomination of a transmission.

As a result Daimler Engineers seem to have deactivated the previous limp-home system, putting the car in third gear without a serious warning to the customer such that when the car is restarted a self check restores the car to normal functioning (gear change available) until the next occurrence of sensor failure. In this way most customers would not even notice the defect but in rare case if the defect occurs while the customer is overtaking, without warning he may be unable to accelerate and may die as a result.

Even after that while examining the car, it may easily be said 'THAT THERE WAS NO WARNING ON THE DASHBOARD AND THRERFORE THERE WAS NO FAILURE'. Only the company engineers would be able to go into the stored faults and see the KM reading of Fault occurrence whereby the evidence is totally within their control!! Aftermarket scanners are not allowed to display THIS information.

Understanding the risks Daimler AG has turned off the warning system and they use this as a trick to replace affected parts without admitting the failure. This is a case of increasing the customer's exposure to death just to avoid a recall campaign. Also as in the case of the SBC brakes it is likely that a recall campaign of this nature would be logistically and technically such that it would inevitably lead to the BANKRUPTCY OF DAIMLER AG, considering all implications, and severe criminal liabilities including imprisonment.

After two car's belonging to our companies have been found and proved to have these failures along with a large number of our customer's cars, we have been refused even a response to our questions!!!

Customers have even been asked to bring back their cars when 'alleged' defect appears which further deceives them to believe that the fault is not serious. The same defects are known worldwide and there is evidence of total disgust at this cover-up.

Glycol from coolant radiators is also known to contaminate the transmission fluid for which documents are circulated to dealers and later the faulty radiators were redesigned with no accountability to affected customers.

Information of valve body change is never admitted but evidence including constant new part numbers raise the question of ongoing R&D at the cost of customers lives.

We have ourselves been locked in gear, unable to down/up shift in a moving car while overtaking and so have our customers. As can be seen from our Youtube videos every permutation of the sensor failures admitted in the documents has been caught live by us and after importing a scanner from Autologic UK we were able to see the internal/turbine/output speed sensors in total failure while the warning systems remained deactivated.

We are in court against Daimler AG and Mercedes Benz India yet we have been refused any answer while the very defects in the cars are covered in the company’s documents. In fact as can be seen here Daimler AG treats a moving car with a locked gearbox as a regular event needing valve body replacement and now refuses to answer when asked the following question:

If the self diagnosis system is programmed to lock the car in the third/running gear (without dashboard warning as proved) what is the risk to a customer’s life in a moving car?

The answer to this question alone could see Daimler AG charged with manslaughter!!!

E350 Transmission Problems

No.Measure/Info. No.Recived DateService Measure / InformationArea / Item AffectedModel ClassModel EngineTypeChassis / Vin No Range
1A/C No: 27 270 01 2005-03-03Replacement of defective Transmission adaptor (Electronic coupling ) to avoid leakage of transmission fluidAutomatic Transmission C ,E ,S ALL 203 ,211 ,220 Limited list provided
2A/C No: 27 270 01 2005-03-15Instruction to put blue dot on replaced Transmition adaptorAutomatic Transmission C ,E ,SALL 203, 211, 220Limited list provided
3A/C No: 27 270 01 2005-12-20Modifaction in service measure dt. 03/03/2005 to replace transmision adaptor to stop leakageAutomatic Transmission C ,E ,SALL 203 ,211 ,220Limited list provided
4S.I.No: IND 27/003 2006-03-31Information showing full knowledge of glycol contamination in transmission from coolant radiatorAutomatic Transmission E ,CLK ,CALL 211 ,208 ,203Not Disclosed
5A/C No: 27 950 31 2007-02-20Install new software due to high friction setting of torque converter and other undisclosed defects Automatic Transmission M ,C ,E ,CLK ,CLS ,S ,SL ,R ALL 164 ,203 ,211 ,209 ,219 ,221 ,230 ,251 Limited list provided
6S.I.No: IND 27/002 2006-03-16Instruction on shift problems in transmission 722.9 showing deep knowledge of failures Automatic Transmission ALLALL ALL Cars with transmission 722.9
7S.I.27.00-P-0010A 2008-10-10Service information showing new transmission and electro hydraulic unit are fitted from 2009 to avoid quality problems Automatic Transmission ALL ALL ALL Cars with transmission 722.9
8GI27.50-P-035556 2009-02-19Information on failure of transmission showing knowledge of gear shift failure while driving Automatic Transmission ALL ALL ALL Cars with transmission 722.9