Common 6.4 L Powerstroke Transmission Problems With Solution

Ford 6.4L Powerstroke comes in two transmission variants – Automatic & Manual. The automatic transmission is a 5-speed transmission, called 5R110W. 

The other transmission is a 6-speed manual transmission & it’s called ZF S6-750. Both of the transmissions are great in their field. However, they’ve some common issues that people are constantly facing & complaining about. 

Don’t worry if you own any of these transmissions with your 6.4L Powerstroke. In this article, I’ll be mentioning five of the most common 6.4L Powerstroke problems & solutions. 

Common 6.4 L Powerstroke Transmission Problems

In this segment, I’ll be explaining the five most common transmission problems of a 6.4L Powerstroke. 

1. Bad or Failing Shift Indicator

One of the worst problems of the 6.4L engine is the malfunctioning shift indicator. You’ll get CEL (Check Engine Light) and other symptoms like wrong gear reading while facing this issue. 

Sometimes, you won’t see the gear indicator moving at all & that’s the worst situation you can fall into. Your shift indicator is important & needs to be fixed as soon as possible. 

2. Low Transmission Fluid Level

Whether it’s an automatic transmission or a manual transmission, it will use transmission fluid while shifting gears up & down. That being said, low transmission fluid problems can happen in both automatic & manual transmissions. 

The 6.4L engine comes with two transmission options (ZF S6-750 & 5R110W) & both of them are prone to low transmission fluid problems. It can happen due to several reasons such – Crack in Fluid LIne, Faulty Transmission Pan Gasket & so on. 

3. Delayed Gear Engagement 

The 5R110W transmission faces delayed gear engagement the most (compared to the other transmission ZF S6-750). You’ll notice your transmission isn’t responding for a couple of seconds if you try to shift gears. 

This problem isn’t a crucial one until it takes a very long time to respond. It’s believed that if your transmission is taking more than 1 minute to respond, chances are – it won’t respond ever. 

4. Faulty Transmission Range Sensor

The transmission range sensor helps with reading/recording transmission speed. Later on, it notifies the PCM (Powertrain Control Module) to shift the gears accordingly. 

You won’t be able to shift your gears if you have a faulty transmission range sensor. Instead of shifting gears upon your command, a faulty transmission range sensor imposes its own will while shifting gears. 

5. Erratic Experience in Tow/Haul Mode

If you’re riding haul areas without any problem, take a moment to thank the Tow/Haul Mode of your vehicle. This mode helps drivers to tackle those areas without damaging the vehicle (internally or externally).

As the tow/haul mode contributes to comfort, you won’t have a good driving experience if something goes off. Malfunctioning tow/haul mode can cause an erratic driving experience & it isn’t very pleasant for sure. 

How to Solve 6.4 L Powerstroke Transmission Problems?

In this segment, I’ll be explaining how you can solve your 6.4L transmission problems. Without further ado, let’s get started:

Solving: Bad or Failing Shift Indicator

This problem occurs due to a faulty shift cable. Over time, your car will go into many situations that might cause the shift cable to loosen. Other than that, clamps & lost bolts can also cause this problem.

Here are the things you can do to fix a bad or failing shift indicator: 

  • Inspect The Shift Cables/Shift Cable Clamps & Tighten Them If Necessary
  • Check If Any Bolts Are Missing & Fix That
  • Replace The Whole Gear Shift Cable Setup If You Find Them To Be Faulty 

Solving: Low Transmission Fluid Level

Reasons behind your transmission fluid drainage can vary & you’ve to act accordingly. Still, here are the popular troubleshooting methods of fixing a low transmission fluid level problem: 

  • Check & Fix Fluid Line Crack
  • Check For Faulty Axle Failure & Fix it
  • Check & Replace Transmission Pan Gasket
  • Check & Replace Torque Converter

Solving: Delayed Gear Engagement 

Though the main culprit of this delayed gear engagement is the low fluid level, other factors can also cause the issue. Here are things you can check & replace to fix the problem:

  • Replace Transmission Filter 
  • Fix or Replace Worn Transmission Bands
  • Check & Repair/Replace Shift Solenoid & Seals

Solving: Faulty Transmission Range Sensor

Don’t waste your time & money fixing a faulty transmission range sensor; buy new instead. If you’re still facing the problem, consider doing these things mentioned below: 

  • Check For Damaged Wirings & Replace Them
  • Check & Replace Faulty Valve Body
  • Check & Repair/Replace The PCM (Rare Case)

Solving: Erratic Experience in Tow/Haul Mode

It’s mainly a computer problem & can be easily fixed if you reprogramme your powertrain control module. Don’t try to do anything if you’re not an expert or don’t have proper information/tutorials. 

How Often Does a 6.4L Powerstroke Transmission Need To Be Replaced?

You don’t need to replace your 6.4L transmission after a certain period of time. However, you can do some replacements like: 

  • Replace Automatic Transmission Filter & Fluid After 30,000 miles
  • Replace Manual Transmission Fluid After 100,000 miles

Can I Drive a 6.4L Powerstroke With a Transmission Problem?

You can drive a 6.4L Powerstroke with one or several transmission problems, but you shouldn’t. Driving a vehicle with faulty transmission can lead to other engine damages & can cost thousands to repair. 

Frequently Asked Questions – FAQ

How Do I Know If My Shift Solenoid Is Bad?

Your shift solenoid will surely give some symptoms if it’s bad. Here are the symptoms of a bad shift solenoid:

  1. Error in Downshifting
  2. Slipping Transmission Issue
  3. Shifting Gears Feels Stuck in Neutral
  4. Delayed Gear Shifting 

How Do You Know If Gearbox Oil Is Low?

Low gearbox oil can cause sudden shiftings (up & down). Also, you may notice strange grinding noise & rise in RPMs before shifting gears from one to another. Overall, you’ll have a hard time if your transmission fluid is low & it’s easily fixable. 

How Do You Know If Your Transmission Range Sensor Is Bad?

If you’re having issues with the transmission range sensor, all the range sensor-related work will malfunction. For example, you won’t be able to shift out from neutral to drive. Vehicle locking in a single sensor & wrong gear shifting are also indicators of a faulty range sensor. 

Conclusions

I hope this article was helpful enough to know the common 6.4 L Powerstroke transmission problems. Besides the problems, I’ve also discussed how to fix/solve them. 

Now it’s up to you whether you want to solve the problems on your own or just hire somebody to do that for you. Keep in mind you’ll have to pay an extra $75 to $150 per hour if you outsource the work.