Fixed my clunky down shifting

[Kelvin]

I did some update to my 2021 Lariat 3.5EB transmission at the weekend ( it is 55K kilometers now), and it seems make it much smoother when changing gears, almost like new.
My F150 used to be silky smooth when it was new purchased, after about 20K kilometers, it started showing clunky when changing gear between 5, 4, 3.
So I did drain and refill only when it hit 30K kilometers, but clunky symptoms seems no change and even worse as time went by. It got to the point when light brake to stop (like city drive with red light), from 5 down to 3, it would suddenly has a big bump, like it got rear ended, which is really uncomfortable.
Well, I searched up and down the forum, and I used Forscan to clean adaptive table and stop using adaptive learning, this seems fixed the problem when gear up shift, I don't feel any clunky up shift anymore. However, the down shift clunky still persist, and the random "rear end" bump still there.
Then I adapted my own driving habit, when doing brake, I always step on brake multiple times instead of steady step on brake paddle, especially when it shift down from 5 to 4, release the brake and brake again, this can avoid the down **** clunky, and avoid the `rear end` bump.
Still not happy with it, downshift was still rough, and besides, and I had to be aware the way how I brake.

After countless google search, I decided to do something about it.
Found Sonnax has some parts/kits for valve body for dealing with clunky shift. Bought some parts from Sonnax for valve body piston update, and I did the update fixes.
It took me nine hours to finish, mainly because I had to craw in and craw out too many times on drive way under the truck, and I don't have good fluid extractor or sucking gun, but I did it.
After few driving around, it seems fixed the clunky issue, I don't need to worry about how I brake now, just brake like driving any other car and I don't feel the hard down shift no "rear end" bump,
but time will tell if it is because of the parts fixes or because of the transmission oil change.

So for anyone who are having the clunky issue, maybe you can give it a try too.

The parts from Sonnax,
I only bought these two parts: Main pressure regulator valve kit, and Solenoid stabilization clip insert.

For the main pressure regulator value kit, the spring comes with it is thin and weak compare to what it has in stock valve body, and when I observed the boar, it seems no scratch or damage, then I decided to stay with stock piston and spring but only replace the end plug with Sonnax's end plug with o ring.
For the solenoid clip inserts, before install it, you can definitely rock the solenoids and feel some wiggle play, after put in the clip inserts, none of the 6 solenoid has any play room.

Here are two youtube I watched before I did my job:
How remove valve body:
How to split upper and lower valve body:

Overall, the job seems easy enough for me to do it on my drive way.
The valve body is pretty serviceable, but pay attention to these and do it carefully otherwise, it will cause damage and can not recover:

#1 The bolts of valve body: they use E torx 12 socket, and it is very easy to strip it, so pay attention and must use good socket, otherwise you will be screwed, because it need to torque to 106 inch/pound.
#2 The sensor on the bottom: This sensor is mentioned in the second Youtube video that you need to disconnect before split valve body. The sensor is using plastic stuff for its position, since the valve body is a bit heavy, be very careful when you handle the valve body, not to touch that sensor with force, otherwise, the little plastic tab may break and it can never position itself in right direction. So pay attention and careful look at it, you will understand what I am talking about.

When installing valve body back to transmission case, the valve body is kind of heavy and my arms were giving up. So I used a jack to help support my arms, and it was much easier for my arm muscle.
And as for mercon ULV fluid, I prepared 14 bottle (14 quarts) instead of only 6-7 bottles. which I am glad I had that many bottles. Because dropping the filter would lose 6 to 7 quarts of fluid, but after dropping of the valve body, it will drain more fluid, and almost drain all of it, I ended up refill back about 11 bottles of ULV fluid.

For the torque spec, the dealer where I bought transmission oil could not find it or they just don't want to find it for me, so I did print an image from one of the youtub (I can not find that youtube anymore), and here it goes

:

Again, this is my own experience, just sharing what I did and what I had.
Anyone do this on your own risk, I am not responsible for any consequence or damage for your own doing.

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[Kelvin]

I also found a trick to replace all transmission oil in one time.
That is when dropping pan and replace filter, you can loose the 8 bolts that are holding the valve body, and let valve body loose some space, then transmission oil within transmission and torque converter will also start to drain. By doing that, it actually drains another 5-6 quarts of fluid, so that would almost drain all fluid in total of around 12 quarts.
Just remember to torque those bolts back to 89 lb-in.
The 8 bolts are easy to identify, they have an arrow mark on the valve body

 

[Davidwnuc]

Sonnax…

Any updates you would like to share? I have been looking at the sonnax stuff lately

 

[Ford guy]

I did some update to my 2021 Lariat 3.5EB transmission at the weekend ( it is 55K kilometers now), and it seems make it much smoother when changing gears, almost like new.
My F150 used to be silky smooth when it was new purchased, after about 20K kilometers, it started showing clunky when changing gear between 5, 4, 3.
So I did drain and refill only when it hit 30K kilometers, but clunky symptoms seems no change and even worse as time went by. It got to the point when light brake to stop (like city drive with red light), from 5 down to 3, it would suddenly has a big bump, like it got rear ended, which is really uncomfortable.
Well, I searched up and down the forum, and I used Forscan to clean adaptive table and stop using adaptive learning, this seems fixed the problem when gear up shift, I don't feel any clunky up shift anymore. However, the down shift clunky still persist, and the random "rear end" bump still there.
Then I adapted my own driving habit, when doing brake, I always step on brake multiple times instead of steady step on brake paddle, especially when it shift down from 5 to 4, release the brake and brake again, this can avoid the down **** clunky, and avoid the `rear end` bump.
Still not happy with it, downshift was still rough, and besides, and I had to be aware the way how I brake.

After countless google search, I decided to do something about it.
Found Sonnax has some parts/kits for valve body for dealing with clunky shift. Bought some parts from Sonnax for valve body piston update, and I did the update fixes.
It took me nine hours to finish, mainly because I had to craw in and craw out too many times on drive way under the truck, and I don't have good fluid extractor or sucking gun, but I did it.
After few driving around, it seems fixed the clunky issue, I don't need to worry about how I brake now, just brake like driving any other car and I don't feel the hard down shift no "rear end" bump,
but time will tell if it is because of the parts fixes or because of the transmission oil change.

So for anyone who are having the clunky issue, maybe you can give it a try too.

The parts from Sonnax,
I only bought these two parts: Main pressure regulator valve kit, and Solenoid stabilization clip insert.

For the main pressure regulator value kit, the spring comes with it is thin and weak compare to what it has in stock valve body, and when I observed the boar, it seems no scratch or damage, then I decided to stay with stock piston and spring but only replace the end plug with Sonnax's end plug with o ring.
For the solenoid clip inserts, before install it, you can definitely rock the solenoids and feel some wiggle play, after put in the clip inserts, none of the 6 solenoid has any play room.

Here are two youtube I watched before I did my job:
How remove valve body:
How to split upper and lower valve body:

Overall, the job seems easy enough for me to do it on my drive way.
The valve body is pretty serviceable, but pay attention to these and do it carefully otherwise, it will cause damage and can not recover:

#1 The bolts of valve body: they use E torx 12 socket, and it is very easy to strip it, so pay attention and must use good socket, otherwise you will be screwed, because it need to torque to 106 inch/pound.
#2 The sensor on the bottom: This sensor is mentioned in the second Youtube video that you need to disconnect before split valve body. The sensor is using plastic stuff for its position, since the valve body is a bit heavy, be very careful when you handle the valve body, not to touch that sensor with force, otherwise, the little plastic tab may break and it can never position itself in right direction. So pay attention and careful look at it, you will understand what I am talking about.

When installing valve body back to transmission case, the valve body is kind of heavy and my arms were giving up. So I used a jack to help support my arms, and it was much easier for my arm muscle.
And as for mercon ULV fluid, I prepared 14 bottle (14 quarts) instead of only 6-7 bottles. which I am glad I had that many bottles. Because dropping the filter would lose 6 to 7 quarts of fluid, but after dropping of the valve body, it will drain more fluid, and almost drain all of it, I ended up refill back about 11 bottles of ULV fluid.

For the torque spec, the dealer where I bought transmission oil could not find it or they just don't want to find it for me, so I did print an image from one of the youtub (I can not find that youtube anymore), and here it goes

:

Again, this is my own experience, just sharing what I did and what I had.
Anyone do this on your own risk, I am not responsible for any consequence or damage for your own doing.

I’m curious about the ability to drain another 5-6 quarts out of the 10 speed simply by loosening the 8 valve body bolts. That is huge and I’ve never heard anyone talk about this. Anybody have any input on doing this? Any downside to it?

 

[22Platinum]

I’m curious about the ability to drain another 5-6 quarts out of the 10 speed simply by loosening the 8 valve body bolts. That is huge and I’ve never heard anyone talk about this. Anybody have any input on doing this? Any downside to it?

https://www.americantrucks.com/ppe-f150-heavy-duty-cast-aluminum-transmission-pan-raw-328053200.html

I'm gonna install this soon to do just that; drain and fill with the oil changes

 

[Kelvin]

Any updates you would like to share? I have been looking at the sonnax stuff lately

So far so good, it has been almost 5K kilometers in 4 months, although as I remember I did experience two big clunks when going big uphill when I need to easy throttle, (I would think this is more relating to timing control of software), other than that, everything is smooth like new.

In daily city drive, I don't have any clunk stress anymore. When transmission is cold, it runs silky smooth and feel nothing, when transmission is hot, I can still feel some tiny gear changes, but that is all.

 

[freewayman]

So far so good, it has been almost 5K kilometers in 4 months, although as I remember I did experience two big clunks when going big uphill when I need to easy throttle, (I would think this is more relating to timing control of software), other than that, everything is smooth like new.

In daily city drive, I don't have any clunk stress anymore. When transmission is cold, it runs silky smooth and feel nothing, when transmission is hot, I can still feel some tiny gear changes, but that is all.

These big uphill clunks, do you mean like easing off on the throttle when say you are at 50kmph in 5th gear?

For me, there is this large slope uphill (i.e. 7% grade) leading to my house. The speed limit is 50kmph but drops to 30kmph because of a school zone. Usually I let off on the throttle, no brake, to drop to 30km/h. But sometimes when it downshifts as I slow down and/or step on the throttle again to maintain 30, it will clunk into 3rd. This is the most often scenario where I experience the clunk. Other times it's more of a mechanical "click" sound, I think this might be the torque converter clutch releasing? Only other time it happens is also usually on inclines at slow speeds where I'm on and off the throttle very quickly, where it seems like there might be some load reversal on the driveline. Also I suspect once again it has to do with the torque converter unlocking as it only happens during these low speed medium load situations around 3rd gear.

(Also noticed u are from Vancouver, I'm living in Burnaby right now and you might know which hill I'm talking about- Kensington avenue northbound near Halifax St in burnaby. The park zone is sumas park.)

Another thing Occasionally I'll get a thud in the 10-9 downshift if the transmission is at a low rpm in 10th gear under some boost and load around 50mph/80kmph and finally decides it needs to downshift. Note that this this is different than the clunk at low speeds, it's more of a firm shift and I think this is normal because it has to quickly downshift to compensate

Other than that- Like you, my transmission is very smooth otherwise on both upshifts and downshifts, in town or highway. Most times I cant feel the upshifts or downshifts at all.

 

[Kelvin]

These big uphill clunks, do you mean like easing off on the throttle when say you are at 50kmph in 5th gear?

For me, there is this large slope uphill (i.e. 7% grade) leading to my house. The speed limit is 50kmph but drops to 30kmph because of a school zone. Usually I let off on the throttle, no brake, to drop to 30km/h. But sometimes when it downshifts as I slow down and/or step on the throttle again to maintain 30, it will clunk into 3rd. This is the most often scenario where I experience the clunk. Other times it's more of a mechanical "click" sound, I think this might be the torque converter clutch releasing? Only other time it happens is also usually on inclines at slow speeds where I'm on and off the throttle very quickly, where it seems like there might be some load reversal on the driveline. Also I suspect once again it has to do with the torque converter unlocking as it only happens during these low speed medium load situations around 3rd gear.

(Also noticed u are from Vancouver, I'm living in Burnaby right now and you might know which hill I'm talking about- Kensington avenue northbound near Halifax St in burnaby. The park zone is sumas park.)

Another thing Occasionally I'll get a thud in the 10-9 downshift if the transmission is at a low rpm in 10th gear under some boost and load around 50mph/80kmph and finally decides it needs to downshift. Note that this this is different than the clunk at low speeds, it's more of a firm shift and I think this is normal because it has to quickly downshift to compensate

Other than that- Like you, my transmission is very smooth otherwise on both upshifts and downshifts, in town or highway. Most times I cant feel the upshifts or downshifts at all.

Yes, that is exactly what happened.
It was like driving up hill, and suddenly ease throttle (still on light throttle), then it get bump gear 3, or I feel like I did ease the throttle when the transmission just right at the moment to down shit, that cause the clunk too.

If I slowly ease throttle, then it will downshift smooth.

Before my fix, I think my torque converter is doing locking/unlocking mostly at gear 3. Because it feels like gear change, but still stay on 3. After the fix, I almost won't notice torque converter locking or unlocking anymore.

 

[freewayman]

Yes, that is exactly what happened.
It was like driving up hill, and suddenly ease throttle (still on light throttle), then it get bump gear 3, or I feel like I did ease the throttle when the transmission just right at the moment to down shit, that cause the clunk too.

If I slowly ease throttle, then it will downshift smooth.

Before my fix, I think my torque converter is doing locking/unlocking mostly at gear 3. Because it feels like gear change, but still stay on 3. After the fix, I almost won't notice torque converter locking or unlocking anymore.

Yeah good to know it's not just me then, in that case I think it's just the characteristic of the programming/transmission on inclines so nothing to worry about

Usually I don't feel the torque converter unlock/lock during normal acceleration/deceleration i.e. from a stop, but I definitely know it's there if I look at the RPMs

 

[Kelvin]

I’m curious about the ability to drain another 5-6 quarts out of the 10 speed simply by loosening the 8 valve body bolts. That is huge and I’ve never heard anyone talk about this. Anybody have any input on doing this? Any downside to it?

I believe when you loose valve body bolts, and loose valve body while still attaching to transmission case, it open the sealed pressure channel from valve body to transmission, that it allows draining fluid inside of transmission clutches and torque converter.
One downside I can think of is, if you drop too much space of valve body, there are two rubber seals on the back of valve body may be out of its position, the whole valve body won't sit back correctly, then you will have to disconnect wires, drop the whole thing and re-install. That is a pain

 

[freewayman]

I believe when you loose valve body bolts, and loose valve body while still attaching to transmission case, it open the sealed pressure channel from valve body to transmission, that it allows draining fluid inside of transmission clutches and torque converter.
One downside I can think of is, if you drop too much space of valve body, there are two rubber seals on the back of valve body may be out of its position, the whole valve body won't sit back correctly, then you will have to disconnect wires, drop the whole thing and re-install. That is a pain

Hi Kelvin, I had a question. Those clunky downshifts you felt initially, before adding your new parts to the valve body, did they happen all the time or was it intermittent? I'm really starting to think maybe it's something in the valve body for me. It doesn't happen most of the time, but when I gently/slowly brake to a stop sometimes Ill get a clunk, other times it'll be more like a bump feeling, it seems to be when the torque converter unlocks.

 

[Kelvin]

Depends on how I brake.
If I pressure on brake firmly, it always got clunky, sometimes it was big bump like got hit, and also I could feel the TC unblocking at gear 3.

If I did like brake and let go and brake and let go, it could be smoother without clunky, but that was very annoying and not easy.

That clunky shifting was getting worse. I bought my F150 new, and it was very smooth until one year later it started clunky shifts

Now my F150 is silky smooth, most of time I don't notice its gear shift.

 

[freewayman]

Depends on how I brake.
If I pressure on brake firmly, it always got clunky, sometimes it was big bump like got hit, and also I could feel the TC unblocking at gear 3.

If I did like brake and let go and brake and let go, it could be smoother without clunky, but that was very annoying and not easy.

Now my F150 is silky smooth, most of time I don't notice its gear shift.

Interesting. For me if I brake firmly, it will downshift 5-3-1 smoothly. However, if I am light on the brake, it will sometimes do 5-4-3-1, and I feel/hear the TC unlocking. Sometimes it's a loud clunk, other times it's more of a jerk/thud.

Also, exact same thing for me if let go off the brake right before it downshifts into 3, it'll be smooth.

I'm bringing the truck in next week to the dealer to see what they say. Last month they already reset the adaptive tables but nothing really changed for it. Hopefully they can figure out what is going on lol. Ill be sure to ask about the possibility of the valve body being an issue.

Thanks again for your advice.

 

[Kelvin]

Oh my bad, I meant light pressure steadily on brake to stop always got clunky.
Hard brake to stop most of times were smooth.
If I was on uphill with light throttle, I could get a huge clunky when it down shift from 4 to 3 to get more power almost every time, like it hesitate to downshift and when it did, it was bit late.

But all those troubles are gone for now. I am enjoying it every day.

Wish you good luck

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