Torque Converter Shudder Adventure

[DWG]

As I think most every one here knows. This is a known unfortunate issue with the 8F35 transmission. There are several TSB's for my 19 Edge which basically tell the Dealer to flash the PCM with the latest software version. It has not helped and the Dealer now just says it is normal. The shudder/buck for me only happens when initially driving from a cold start at just below 20 mph. Once I am out of the neighborhood and can get up to 45 - 50 mph the shudder/buck goes away and does not come back until the car is cold again. It does not happen every time I drive from a cold start. It seems to be outside temperature sensitive happening primarily in warmer weather. It happens to a lesser degree with my 20 Escape and surprisingly I had it happen a couple of times on really hot days with my 24 BS which only has about 1800 miles on it. It happening with my brand new BS was very disappointing in that obviously Ford does not have a fix. It also makes me think that some of these fixes that others are coming up with may only be temporary or would not apply in my case (especially on a brand new car).
On the Edge forum some are posting that replacing the EGR valve fixed their issue. Also as I mentioned in my case the shudder/buck is only when the vehicles are cold in warmer temperatures and only at speeds below 25 mph so some of the shudder/bucking others have experienced sounds different than what I experience. As long as my symptoms don't change I am resigned to consider the issue a characteristic of the transmission.

thomas23, please keep us posted on how the lubegard is holding up.

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[thomasm23]

I now have 124,000 miles. The torque converter shudder has started to come back.

This is my plan: I believe my issues are fluid related. I want to do two consecutive fluid changes. This will help dilute the existing fluid. I will then add a new tube of Lubegard.

Dealers do not make a large amount in selling vehicles. The service department and body shop generate the profits that keep the dealership going.

Dealers make a lot from servicing transmissions. The local transmission shop is usually 30-50% less.

 

[DNorton]

The shudder drives me insane. I pretty much want to speed everywhere to avoid it. I am still under warranty, so I will mention it to the dealer when I go in for the RDU thing...

Curious what you were told about getting an RDU, if you need one.
My dealership has had one ordered for me that’s been on back order for eight weeks, and they say the order is expedited. They can’t even give me an estimate as to when it might arrive.
My RDU total blew out a little more than two weeks after they gave me my car back to wait on parts. A week later I had it towed to the dealership and have had a rental (they covered the cost) for three weeks now.
Anyhow, I hope you have better luck than I’m having!

 

[Cursed Bronco]

Curious what you were told about getting an RDU, if you need one.
My dealership has had one ordered for me that’s been on back order for eight weeks, and they say the order is expedited. They can’t even give me an estimate as to when it might arrive.
My RDU total blew out a little more than two weeks after they gave me my car back to wait on parts. A week later I had it towed to the dealership and have had a rental (they covered the cost) for three weeks now.
Anyhow, I hope you have better luck than I’m having!

My RDU currently hasn't been diagnosed as bad. I am waiting on the fix to install the new drain tube. They told me it is likely done for, but they can't replace the RDU while still waiting on the parts to fix the vent hose since it has to go back together according to new speck. I have been waiting nearly 3 months for the new vent hose and other associated parts to arrive to even have that fixed. Then I can drive it home and immediately take it back and tell them the new fluid did nothing.

 

[DNorton]

My RDU currently hasn't been diagnosed as bad. I am waiting on the fix to install the new drain tube. They told me it is likely done for, but they can't replace the RDU while still waiting on the parts to fix the vent hose since it has to go back together according to new speck. I have been waiting nearly 3 months for the new vent hose and other associated parts to arrive to even have that fixed. Then I can drive it home and immediately take it back and tell them the new fluid did nothing.

Oh geez!! That sucks!! I sure hope things work out. It’s so frustrating.

 

[thomasm23]

I finally had a chance to change the transmission fluid. Two weeks ago, I purchased 10 quarts of Motorcraft ULV transmission fluid from the dealer.

I drained the fluid and then removed the leveling plug. The plug is lower in the case than I thought. You will need a 10mm hex socket with an extension. I removed the left front wheel for easier access. It will take around 10-15 minutes for the fluid to drain. You will only be able to get a little over 4 quarts out. I reinstalled the drain plug with a 14mm socket.

After removing the airbox for access, I started to add the first quart of new fluid. After 2 quarts, I started the vehicle to allow the fluid to circulate because it started draining out of the leveling plug. I ended up adding a little over 4 quarts. Keep in mind that the fluid must be between 185-200 degrees F. I used a laser temperature tool aimed in the leveling plug hole directly on the fluid. It will take some time to get up to temperature. If you do not do this, you will overfill the transmission.

Because the torque converter cannot be drained, I then drove the vehicle for 40 minutes and then drained the fluid again. My goal was to dilute the old fluid as much as I could with two consecutive drain and fills. With the second fill, I added a bottle of Lubegard Platinum Automatic Transmission Fluid Protectant. After bringing the fluid up to the required temperature, I reinstalled the leveling plug, the left front wheel and the airbox.

When driving the vehicle, I noticed that the shudder was less but still present. When driving at highway speeds with the cruise control set, the tachometer would bounce every second.

After a week, I added a tube of Lubegard Instant Shudder Fixx. This removed any leftover shudder. The transmission is working great now.

I believe the Motorcraft ULV transmission fluid has a degradation issue after long term use. I now have 139,000 miles and will be doing single drain and refills every 30,000 miles.

 

[Mark S.]

I believe the Motorcraft ULV transmission fluid has a degradation issue after long term use. I now have 139,000 miles and will be doing single drain and refills every 30,000 miles.

Had you done any previous transmission fluid maintenance?

 

[thomasm23]

Had you done any previous transmission fluid maintenance?

I had the dealer drain and refill the transmission fluid at 117,000 miles. This did not rectify the shudder. See original post.

The dealer should be inspecting the transmission fluid during a normal oil change. If they are doing an inspection, how are they doing this and what are they looking for?

The color of the fluid is not necessarily indicative of an issue.

The transmission fluid is circulated under pressure through the torque converter and other areas of the transmission. The transmission fluid is transferring torque from the engine flywheel to the transmission. The only direct mechanical transfer occurs in 7th and 8th gears, I believe, when the torque converter locks up in overdrive.

There seems to be a “friction” issue with the ULV fluid causing the shudder in the torque converter.

 

[thomasm23]

Well the torque converter shudder is finally gone and it is running great. But, it looks like the shudder may have contributed to a need to replace the engine mounts.

https://www.broncosportforum.com/forum/threads/engine-mounts-replacement.13362/

 

[DukeNukem81]

Can someone tell me how I can add this Shudder fix to my 2021 Base model 1.5l please

 

[thomasm23]

Can someone tell me how I can add this Shudder fix to my 2021 Base model 1.5l please

Please read the original post on this thread.

You will need to remove the air box and front snorkel for access. This is very easy to do.

Remove the vent cap from the rubber hose on top of the transmission. Using a proper funnel inserted through the hole in the battery tray, to support the funnel, with the end of the funnel inserted into the rubber fill port.

 

[DukeNukem81]

Thank you Thomas! Got it done today and has seemed to alleviate the shudder for now. Very thankful to you

 

[thomasm23]

Thank you Thomas! Got it done today and has seemed to alleviate the shudder for now. Very thankful to you

Good to hear.

There are some on this forum that do not believe that you can fix the torque converter shudder issues with a simple additive.

It is truly amazing how it works.

Think of a Slip N’ Slide with not enough water covering the surface. Your body will not smoothly slide on the surface. If enough water is used, your body will slide smoothly on the surface.

The additive uses friction modifiers to let the transmission fluid transfer torque smoothly.

 

[thomasm23]

Update.

I now have 151,000 miles. For the last week the shudder has come back.

I purchased another tube of Lubegard Instant Shudder Fixx. 15 minutes later and the shudder is totally gone.

I seem to get 12,000 to 15,000 miles between adding the Lubegard. I am doing a drain and refill of the ULV transmission fluid every 30,000 miles.

 

[harrkaep]

I finally had a chance to change the transmission fluid. Two weeks ago, I purchased 10 quarts of Motorcraft ULV transmission fluid from the dealer.

I drained the fluid and then removed the leveling plug. The plug is lower in the case than I thought. You will need a 10mm hex socket with an extension. I removed the left front wheel for easier access. It will take around 10-15 minutes for the fluid to drain. You will only be able to get a little over 4 quarts out. I reinstalled the drain plug with a 14mm socket.

After removing the airbox for access, I started to add the first quart of new fluid. After 2 quarts, I started the vehicle to allow the fluid to circulate because it started draining out of the leveling plug. I ended up adding a little over 4 quarts. Keep in mind that the fluid must be between 185-200 degrees F. I used a laser temperature tool aimed in the leveling plug hole directly on the fluid. It will take some time to get up to temperature. If you do not do this, you will overfill the transmission.

Because the torque converter cannot be drained, I then drove the vehicle for 40 minutes and then drained the fluid again. My goal was to dilute the old fluid as much as I could with two consecutive drain and fills. With the second fill, I added a bottle of Lubegard Platinum Automatic Transmission Fluid Protectant. After bringing the fluid up to the required temperature, I reinstalled the leveling plug, the left front wheel and the airbox.

When driving the vehicle, I noticed that the shudder was less but still present. When driving at highway speeds with the cruise control set, the tachometer would bounce every second.

After a week, I added a tube of Lubegard Instant Shudder Fixx. This removed any leftover shudder. The transmission is working great now.

I believe the Motorcraft ULV transmission fluid has a degradation issue after long term use. I now have 139,000 miles and will be doing single drain and refills every 30,000 miles.

Can I ask you what the ratio of Lubegard Platinum is? Am I correct that it's 1oz:1qt of Mercon

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