[black335x]

Whenever I am WOT while in M mode my 3-4 shift is very rough, it takes a while to fully engage 4th. I don’t think I’ve reached any limits of the stock 6AT. And it was serviced 5k mile ago. Any idea what could cause this or how to fix?

[Saif2018]

Originally Posted by black335x

Whenever I am WOT while in M mode my 3-4 shift is very rough, it takes a while to fully engage 4th. I don’t think I’ve reached any limits of the stock 6AT. And it was serviced 5k mile ago. Any idea what could cause this or how to fix?

Serviced as in Oil and pan/filter change or Mechatronic Sleeves, seals and solenoids, pan/filter and transmission oil change?

[iqraceworks]

See above. How was it serviced? Rough shifts can be caused by cracked sleeve seals, D seal, and/or bad shift solenoids....were those replaced??

[black335x]

Originally Posted by Saif2018

Serviced as in Oil and pan/filter change or Mechatronic Sleeves, seals and solenoids, pan/filter and transmission oil change?

All but sleeves, I am tuned on e60 right now stock turbo though. So whatever power level that is. I don’t think that would be close to the limits of the 6AT

[iqraceworks]

Originally Posted by black335x

All but sleeves, I am tuned on e60 right now stock turbo though. So whatever power level that is. I don’t think that would be close to the limits of the 6AT

A cracked sleeve sleeve could be causing your issues.

[black335x]

Originally Posted by iqraceworks

A cracked sleeve sleeve could be causing your issues.

It’s only my 3-4 while at WOT

[iqraceworks]

Originally Posted by black335x

It’s only my 3-4 while at WOT

And? You don't think that could be caused by one of the multiple seals being cracked and leaking off fluid pressure?

[black335x]

Originally Posted by iqraceworks

And? You don't think that could be caused by one of the multiple seals being cracked and leaking off fluid pressure?

I do think it could cause it. But the trans has 60k miles on it. And it’s only been tuned for 12k, I know xhp has the line pressure bump option which I tried and it didn’t do anything for me.

[whyzee125]

Did you use OEM fluid? Did it shift smoothly before the XHP? Did you do the adaptation drive cycles before getting on it after installing XHP?

[Saif2018]

Originally Posted by black335x

I do think it could cause it. But the trans has 60k miles on it. And it’s only been tuned for 12k, I know xhp has the line pressure bump option which I tried and it didn’t do anything for me.

Line pressure bump is for slipping trans which are pushing high torque, not to compensate for rough or clunky shifts.

You need to fully service the trans as mentioned before jumping to any other conclusions. Replace the Mechatronic Sleeves, Seals and Solenoids. Then do the transmission pan/filter and transmission oil change.

[iqraceworks]

Originally Posted by black335x

I do think it could cause it. But the trans has 60k miles on it. And it’s only been tuned for 12k, I know xhp has the line pressure bump option which I tried and it didn’t do anything for me.

Did you do the service on your transmission or did you take it to a shop?

I'm shocked that you had/did a full service on your transmission, where you say they/you also replaced the shift solenoids, (which requires removing the entire valve body), but they/you didn't also replace the rubber sleeve seals and double D seal that are only a few dollars. I mean after you pull the valve body...you literally pull the seals out with a pair of pliers, and press the new ones in with your fingers. Doesn't make sense why anyone would pull the valve body off for new shift solenoids, but not replace the seals while they had it off.

Are you 100% sure you got all of your shift solenoids replaced??

[black335x]

Originally Posted by iqraceworks

Did you do the service on your transmission or did you take it to a shop?

I'm shocked that you had/did a full service on your transmission, where you say they/you also replaced the shift solenoids, (which requires removing the entire valve body), but they/you didn't also replace the rubber sleeve seals and double D seal that are only a few dollars. I mean after you pull the valve body...you literally pull the seals out with a pair of pliers, and press the new ones in with your fingers. Doesn't make sense why anyone would pull the valve body off for new shift solenoids, but not replace the seals while they had it off.

Are you 100% sure you got all of your shift solenoids replaced??

I did the service myself. I only bought the solenoids and completely neglected the seal because I didn’t know I would need them. Stupid mistake on my part. They seemed in good condition when I had everything apart. But I didn’t look to close at them. Do you think it could be cracked after only 60k miles?

[iqraceworks]

Originally Posted by black335x

I did the service myself. I only bought the solenoids and completely neglected the seal because I didn’t know I would need them. Stupid mistake on my part. They seemed in good condition when I had everything apart. But I didn’t look to close at them. Do you think it could be cracked after only 60k miles?

Hard to tell......but it's very common for the seals to crack. And even though the transmission may only have 60k miles on it.....it's still 15-ish years old.

Honestly, you aren't left with many options. Either you pull the pan and valve body and replace the seals and see if that fixes it. Or you keep driving it and see if it fits just breaks something. Or you pay for a full rebuild.....or roll the dice on another used transmission.

Replacing the seals is by far the cheapest and easiest option.

On a side note....did you use OEM ZF shift solenoids, or the aftermarket off brand ones?

[black335x]

Originally Posted by iqraceworks

Hard to tell......but it's very common for the seals to crack. And even though the transmission may only have 60k miles on it.....it's still 15-ish years old.

Honestly, you aren't left with many options. Either you pull the pan and valve body and replace the seals and see if that fixes it. Or you keep driving it and see if it fits just breaks something. Or you pay for a full rebuild.....or roll the dice on another used transmission.

Replacing the seals is by far the cheapest and easiest option.

On a side note....did you use OEM ZF shift solenoids, or the aftermarket off brand ones?

I bought them off FCP Euro so I hope those are the OEM ones. And you seem pretty knowledgeable, do you know the limits of the 6AT?

[iqraceworks]

Originally Posted by black335x

I bought them off FCP Euro so I hope those are the OEM ones. And you seem pretty knowledgeable, do you know the limits of the 6AT?

I'm pushing close to 600hp, and can knock out some pretty quick high 10 second drag strip passes with no issues...with a 6HP21 with 100k+ miles on it. I'm running xHP stage 3.

They can hold quite a bit of power it seems.

[black335x]

Originally Posted by iqraceworks

I'm pushing close to 600hp, and can knock out some pretty quick high 10 second drag strip passes with no issues...with a 6HP21 with 100k+ miles on it. I'm running xHP stage 3.

They can hold quite a bit of power it seems.

Do you have custom setting by chance. I wonder if mine could be causing the rough shift.

[iqraceworks]

Originally Posted by black335x

Do you have custom setting by chance. I wonder if mine could be causing the rough shift.

Honestly, I haven't messed with the setting much. I maxed out the shift speeds, so I'd anything...it made it shift harder. If you are only having a hard 3-4 shift, it's probably something in the transmission..not the xHP settings. You could set it all back to stock and see what that does?

Mine actually has a hard 5-4 downshift......much harder than the other gears. Probably something worn in the valve body, but at this point...I've just gotten used to it.

[black335x]

Originally Posted by iqraceworks

Honestly, I haven't messed with the setting much. I maxed out the shift speeds, so I'd anything...it made it shift harder. If you are only having a hard 3-4 shift, it's probably something in the transmission..not the xHP settings. You could set it all back to stock and see what that does?

Mine actually has a hard 5-4 downshift......much harder than the other gears. Probably something worn in the valve body, but at this point...I've just gotten used to it

I got a log of it. You can see the weird curve. After adjusting xhp settings it’s no lower a rough shift but feels slower than the rest
https://datazap.me/u/black335x/3-4-s...ta=4-18&solo=4

[iqraceworks]

Originally Posted by black335x

I got a log of it. You can see the weird curve. After adjusting xhp settings it’s no lower a rough shift but feels slower than the rest
https://datazap.me/u/black335x/3-4-s...ta=4-18&solo=4

What setting did you adjust?

[black335x]

Originally Posted by iqraceworks

What setting did you adjust?

Lowered shift speed and tq reduction up shifts

[iqraceworks]

Originally Posted by black335x

Lowered shift speed and tq reduction up shifts

I guess if it works...it works. Just keep in mind that it's probably just a bandaid for a bunch gher issue inside the transmission. Does it have rough shifts on the stock transmission tune?

[black335x]

Originally Posted by iqraceworks

I guess if it works...it works. Just keep in mind that it's probably just a bandaid for a bunch gher issue inside the transmission. Does it have rough shifts on the stock transmission tune?

It only has the rough/laggy shift in M mode.