Shudder on WOT 1-2 shift

[Livernois Motorsports]

The root is still physics. I guess if you want to make an existential connection there is always a way to do so.

[AJP turbo]

^ good call I've seen that as well so I'll give her some fluid to see if it helps. ultimately I think the issue should be addressed through the tune though

The shudder is actually primarily caused by fluid cavitation. As the fluid gets more hot and less viscous it will incorporate more air. Thus, creating cavitation. This has NOTHING to do with a tune.

You are going on the assumption that cavitation is the cause....if the tune is the problem then is has EVERYTHING to do with the tune

Perhaps i dont suffer fluid cavitation...how does one prove that fluid cavitation is the problem or even present?

[Livernois Motorsports]

VIA our R&D we have already found and proven that the STOCK vehicle has this issue. It can also hold gear and bang off of the limiter. SO, if the hot completely stock car can suffer from this how exactly is it tune related? We know because we are often tasked with the job of finding these types of issues with factory platforms.

[FoMoCoSHO]

VIA our R&D we have already found and proven that the STOCK vehicle has this issue. It can also hold gear and bang off of the limiter. SO, if the hot completely stock car can suffer from this how exactly is it tune related? We know because we are often tasked with the job of finding these types of issues with factory platforms.

Interesting.

I've experienced it in both cars when tuned, never stock.

If heat is the factor then removing TQ reduction on shifts would exacerbate the situation, correct?

Does the extra pint of fluid help mitigate this without harming the trans?

[SHOdded]

I wonder if extra fluid could help the 6f50 also.

[AJP turbo]

Interesting that you have found so many STOCK cars with this problem...i imagine it would take clear lines and video to see cavitaion at the time of shift

So how does a tune fix fluid cavitation?...perhaps i picked my ass and got lucky.....im not  so arrogant to think my tune fixes fluid cavitation but maybe i dont give myself enough credit

[Livernois Motorsports]

VIA our R&D we have already found and proven that the STOCK vehicle has this issue. It can also hold gear and bang off of the limiter. SO, if the hot completely stock car can suffer from this how exactly is it tune related? We know because we are often tasked with the job of finding these types of issues with factory platforms.

Does the extra pint of fluid help mitigate this without harming the trans?

Yes. That is exactly why we recommend running a pint heavy.

[Zalvern]

Personally I feel it's just Mercon LV breaks down way too fast. Even on stock tune, and a performance tune will only break it down faster. Sure enough, as my MKZ nears 3000 miles the 6F55 is starting to loose its smoothness. Reflashing the transmission doesn't last long in restoring the low gear smooth shifts.

Amsoil ATF lasted longer before the change in transmission feel (about 3000-4000 miles) before the similar symptoms return. Though I did not try the extra pint addition suggestes by Livernois. Can't hurt to add an extra 16 oz of fluid.

Going to start cycling in QuantumBlue Transmission fluid this weekend, though I'll give it the extra pint treatment to see how far it goes.

A tune may speed up the pressure I imagine, but still won't help Mercon LV's (or even Amsoil) limited optimal life span where shifting feels the best at any temperature.

Hence why stock or tune, the performance gets lame quick (but not detrimental to components), especially when out of operating temperature range. It becomes really noticeable during low speed stop and go traffic when letting the computer shift at lower rpms.

[AJP turbo]

When you read up on oil there is no correlation between viscosity and rate of "breaking down"...just like there is no correlation between synthetic oil and how people believe its more "slipperry"

Speculation seems to be at its worst when things are mysterious

Viscosity selection has more to do with bearing tolerances and desired pressure vs temperature

If viscosity and weight meant more protection then we would run 75w-140 in the motor

Actually it is a fact that when all things are equal the oil with the wider viscosity rating will shear faster per amsoil...so 10w-30 will shear less than 10w-40....

[Zalvern]

When you read up on oil there is no correlation between viscosity and rate of "breaking down"...just like there is no correlation between synthetic oil and how people believe its more "slipperry"

Speculation seems to be at its worst when things are mysterious

Viscosity selection has more to do with bearing tolerances and desired pressure vs temperature

If viscosity and weight meant more protection then we would run 75w-140 in the motor

Actually it is a fact that when all things are equal the oil with the wider viscosity rating will shear faster per amsoil...so 10w-30 will shear less than 10w-40....

Ah I should of elaborated by "breaking down". I don't think its nessecary affecting the transmission fluid's weight focus per say. But perhaps other minor additives that say, help keep the chemical bonds consistent.

What we do know and are told (by Ford), is even when Mercon LV turns a brown color that may seem alarming, but isn't in poor condition terms of use. From the bottle its dark red and changes with low mileage use (low as in a few thousand). The oil weight should be fine.

But the chemical science side of me says it still underwent some kind of chemical change beyond just a pigment adjustment.

Thinking on it, break down was a poor choice of words for what I want to target in regards to 6F low gear performance changes at short use intervals. Slight change in chemical make up is what I should say, and that change seems to affect something that makes Livernois find a little extra fluid helps better.

I almost took the initiative of getting the Sonnax zip kit done on my Fusion's 6F35. But then I wasn't fully sold on valve body having a flaw, since fresh fluid always feels great while Mercon LV stays "Dark Redish". Once it turns fully brown with no red after a few thousand miles, it gets more sensitive with the low gear shifts or low rpms.

But that is the only thing to know without an astute oil analysis...think I'll save some of my stock used fluid when I drain it and get it checked. Weight will be fine I'm sure, but I want to know what individual chemicals have changed. Then question how to keep fresh fluid transmission performance for longer than just a few thousand miles.

[SHOdded]

Be good to get some more analytical data, so def send out those used fluids for analysis!

[Zalvern]

Was doing some practicing brake boosting from a dig and shifting into second gear the trans would seemingly shift, then shudder for a second, and then what if feels like shift again and take off as normal. This started to occur a few nights ago and hasn't been consistent but has done it a handful of times since it started. I've done some searching and reading and i'm a little confused as if i should be diagnosing hard parts . . trans,PTU, TC, or address the issue through the tune. The car only has 14k on it and has only been tune for about 3-4 weeks but that doesn't rule out any hard part failures. I'll be loading the stock tune again soon to see if the problem still occurs at stock power levels and trans settings.
What's the consensus from others who have experienced the "shudder"? Was it a tune issue or a hard part issue?

TIA

Upon reading this again, I also wonder if what you call "shuddering" is actually just the AdvanceTrac/ESC system interfering with your desired performance. Did you have traction control off by chance? There are times the computer nannies simply do overreact and will kill your actual power, especially when attempting to downshift accelerate (really annoying especially when the road is dry). It is more likely to trip up in the lower gears and asking to WOT or so. I had similar moments when I was able to brake boost on my tuned Fusion, and turns out it was AdvanceTrac interfering.

Of course, as I read SHO's have a "Track Mode" that disable all the nannies. All I can do (on the MKZ) is turn off the TC.

[Colorado-SHOBro]

^ good call I've seen that as well so I'll give her some fluid to see if it helps. ultimately I think the issue should be addressed through the tune though

Yes yes, very addressable it is lol.

The shift adjustment is more involved than just pressure changes....I actually run high pressures but lower torque reductions

Contrary to popular belief, the factory tq reductions and tq management don't really get in the way of quick, firm shifts....You can have fast shifts with tq reductions in the name of drivetrain preservation

I used to lower shift pressures to avoid the 1-2 shudder, it was not the way....It kind of worked but not really

^i 100% agree with this. my last cars completely stock trans held way more power than it should have and still is at 175k partly because I left torque management in tact and tuned just the pressure tables etc.

^ good call I've seen that as well so I'll give her some fluid to see if it helps. ultimately I think the issue should be addressed through the tune though

The shudder is actually primarily caused by fluid cavitation. As the fluid gets more hot and less viscous it will incorporate more air. Thus, creating cavitation. This has NOTHING to do with a tune.

even if the root of the issue is 100% caused by fluid cavitation i find it hard to believe that the tune has no impact over the shuddering. when cavitation IS present i would imagine depending on the shift strategy of the tune, it could either promote or help prevent the occurrence of the "shudder".
split hairs all you want over exactly what's causing the issue . . . a good or bad tune has an impact.

that being said I did add a bit more fluid but just completed a 700+ mile road trip from CO to Missouri so not a lot of time spent shifting from 1st to 2nd LOL

[GT500R]

http://www.ecoboostperformanceforum.com/index.php/topic,4524.30.html

Change shift pressure to 200?

[StealBlueSho]

Interestingly enough, I started to have this issue as well with my LMS 4+X tune... When I had AJP Turbo's tune which I KNOW produced a hell of a lot more torque I did NOT experience this issue. The only issue I had on the 1st to 2nd shift with AJPTurbo was traction... not once did my PTU or Transmission complain...

I did contact LMS and exchanged emails with Anthony who stated I need to check the fluid, drain/fill, etc.. and run a pint heavy... I had the transfluid serviced less than 5k ago so I know the fluid is good, I checked it today and it was just under the last hash mark before max so I added an additional 16oz of fluid.

Results so far have been more a of single stut on the shift from first to second which is an improvement that COULD be wheel hop. Although tonight I was hammering on it (of course after I told Anthony I think things are good...) and the stut was a bit more pronounced.. interestingly enough, I have only had this issue once the temperatures have dropped into the 40's...

I am going to test it some more.. I have read that some people have asked LMS to fix this and they have by making some adjustments...

ANYWAY... The dagger was that this decided to pop up right in the middle of a guy test driving it who was interested in buying it...