Long story short... When I load a tune that cranks up the shift pressure such as Torrie's or LMS race tune I get a stutter between gear shifts only under WOT... the rpms don't rise like a slipping issue. Tunes that don't have the shift pressure cranked up don't exhibit this behavior at all. The car has been doing this for 18 months or so off an on. Started with Torries tunes.. doesn't seem to get any better or any worse...
Service fluid has been checked, rechecked, and swapped out on the trans and PTU. No visible signs of leaks around the casing...
I can launch the car all day at 2K RPM and she just dips and goes with any issues off the line.. no excessive wheel spin, etc.. but that 1-2 second shift will stutter then catch and go... and sometimes the 2 - 3 shift will do that same...
Thoughts? Opinions? Previous experiences?
I thought lms said this was due to fluid cavitation and to add an extra quart of trans fluid to alleviate.
Agreed, and that was done as well. And it's an extra half quart...
Does Dan Millen recommend overfilling the transmission or was that an idea from someone else at Livernois who may not have appropriate knowledge?
Email from Anthony at LMS.. granted, my car does this with Torries tunes as well.. though, only with the shift pressure dialed up...
QuoteAnthony M (LivernoisMotorsports)
Jan 17, 18:21 COT
Michael,
I am sorry to hear of this. While altering tunes that we know are not having this problem on hundreds of other vehicles to resolve the issue on your vehicle may be a solution, have you tried servicing the transmission to resolve the root cause of the trouble you're having? We have no problem tweaking the tunes for you, but this is an obvious sign that there is something mechanical going on with the transmission that is giving you early indications / warning signs of something worse to come. I can see on the server that there are well over 100 other SHOs running these exact tune files and haven't had any requests to lower shift pressures to fix a stuttering 1-2 shift. We have however found on other SHOs here in the shop that when they seem to have trouble with 1-2 shifting occasionally , they typically need to have the trans fluid service done and then we top them off with an extra pint over the factory fill. Even Ford has found they were having issues in stock form occasionally with the Police pursuit models since they spend a great deal of time idling and then going WOT to pursue a suspect. It's been proven that the fluid was actually cavitating and that over-filling them by a pint has helped to nearly resolve the issue almost every time. Having that extra pint of fluid helps to ensure there is much less of a chance for the fluid to cavitate. If the fluid currently has over 25,000-30,000 miles, it's suggested to drain and refill. Then it's very critical to make certain you fill the fluid, run the car to let the fluid circulate, and then check the fluid again to top it off. Then we suggest to add that extra pint once you are 110% certain it's filled completely. Many people just fill it once and don't check it afterwards which is another well known issue causing them to have a stutter from time to time.
Like I mentioned, we have no trouble adjusting the tunes for you if needed. But we would much rather help you get to the bottom of this instead of tuning around a mechanical issue possibly which may only be a temporary fix causing more harm than good. Overfilling the transmission by a pint (not quart) has been the best thing for the Explorer and SHOs having this issue.
Thank you
Regards,
Anthony
Livernois Motorsports & Engineering, LLC
Phone: 313-561-5500 Fax: 313-730-7500
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Hmm mine did this as well with the boostmax turnes out some how all it does is adds up to 3 psi but after a week it has been gone for couple weeks now
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Maybe I am not giving the car long enough for the adaptive components to do their thing? Realistically I put around 3K miles on it ever 6-8 months...
Many guys with tuned SHOs or MKSs have had the issue. In some cases, fresh fluid has solved it -
or has seemed to. However, the only fix I have heard of that ALWAYS works is backing off the shift pressure.
I think its a common procedure to slightly over fill the Trans and Coolant right above the Top fill line IIRC with the exception of motor oil for good measures. Z
Quote from: Brucelinc on May 11, 2017, 04:10:35 PM
Many guys with tuned SHOs or MKSs have had the issue. In some cases, fresh fluid has solved it -
or has seemed to. However, the only fix I have heard of that ALWAYS works is backing off the shift pressure.
From what I have read, that's seems to be 100% correct. However, Anthony made it appear that it is not common anymore, and the tunes have been revised to address this issue. So for me to ask for a softer shift version was unusual... at least according to LMS..
I had the 1 to 2 Shift stutter. They (LMS) gave me a modified tune to correct the problem. It had zero effect on my performance and zero to 60 times and simply eliminated the stutter. This was probably at least two and a half years ago. It was not an indication that my transmission was on the way out.
Yea, they gave me a softer shifting version... no stutter... and the tranny doesn't feel like it's going pound its way out the side of the car...
Quote from: TSS on May 11, 2017, 08:54:53 PM
I had the 1 to 2 Shift stutter. They (LMS) gave me a modified tune to correct the problem. It had zero effect on my performance and zero to 60 times and simply eliminated the stutter. This was probably at least two and a half years ago. It was not an indication that my transmission was on the way out.
Did you notice a shifting difference? Besides the obvious lack of stutter?
I ran Livernois 4+X for over a year with no stutter. All of a sudden, for no apparent reason, my MKS developed the 1-2 stutter. Livernois sent me the same tune but with reduced shift pressure. That immediately solved the issue.
My concern, however, was why was is fine for a year and then exhibit the bad behavior? I changed out the fluid in the transmission and re-installed the original higher pressure tune. The stutter was gone. Was it the fluid change that "fixed" it, was it just a fluke, was it simply the reflashing? I have no idea. However, after that, I changed the tranny fluid annually and never again had the stutter even with their "race" tune.
As for the the transmission behavior with the reduced pressure, it was noticeably smoother at WOT. With the high pressure tune, I always got a tire chirp on the 1-2 shift at WOT and but with the reduced pressure, I did not. However, like Todd, my 0-60 measurement was just as good with the softer shifts.
Thanks for the detailed information. It doesn't do it every time. Before I go down the path of transmission work/PTU work I wanted to see what others have done. Like I said, LMS made it sound like an oddity. Seems like to me they are dialing it up right the very edge with their race tune as far as the transmission is concerned. Torrie must use that strategy as well... as I know people have mentioned having the same issue with his tunes...
Realistically I could run the softer shift version indefinitely without any issues.
I personally don't notice any difference other than the lack of stutter. I already change my transmission fluid every 18000- 20,000 miles with the B&G service at the dealer. Also change the PTU fluid at the dealer regularly. That also had no effect on the stutter. The only thing that fixed it was the softer version shift tune.
Unlike Bruce, mine did it from day one of the tune. The only way to get rid of it was to put the car back to stock at that time. And recently, I inadvertently loaded the old version after service at the dealer. The first time I did a wide open throttle from a stop, I immediately knew I had loaded the wrong tune because the stutter was back.
I have not added any extra transmission fluid as was suggested at one time as a remedy. I just did not want to do that. I wanted to resolve the issue using the correct manufacturer specified volume of transmission fluid.
This answers my questions. No need to worry about PTU/Transmission stuff..... yet...... eventually the piper will get his payday...
What exactly does this stutter feel like? It isn't just hopping the front tires on the shift is it. Our Explorer did that with a hot tune. It felt pretty violent and I was worried about the trans holding up. It also detonated though so I didn't run the tune.
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Quote from: 16MagSport on May 14, 2017, 11:52:06 AM
What exactly does this stutter feel like? It isn't just hopping the front tires on the shift is it. Our Explorer did that with a hot tune. It felt pretty violent and I was worried about the trans holding up. It also detonated though so I didn't run the tune.
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It's not wheel hop, although it does feel similar...I would say it's wheel hop if I hadn't datalogged the event or had it happen on the 2-3 gear shift too.
On a side note... did a KAM reset after I loaded the standard 4+X Race tune... hasn't stuttered yet... temps are also in the mid 60s... now high 70's... gonna keep an eye on it...
Quote from: StealBlueSho on May 14, 2017, 12:10:47 PM
Quote from: 16MagSport on May 14, 2017, 11:52:06 AM
What exactly does this stutter feel like? It isn't just hopping the front tires on the shift is it. Our Explorer did that with a hot tune. It felt pretty violent and I was worried about the trans holding up. It also detonated though so I didn't run the tune.
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It's not wheel hop, although it does feel similar...I would say it's wheel hop if I hadn't datalogged the event or had it happen on the 2-3 gear shift too.
On a side note... did a KAM reset after I loaded the standard 4+X Race tune... hasn't stuttered yet... temps are also in the mid 60s... now high 70's... gonna keep an eye on it...
What did you select for logging?
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Torque Source...
What did the log show? Did the advance and/or throttle blade angle drop or swing wildly at the time, differently than a smooth shift? Sure sounds like wheel hope since it goes away with a softer shift. Did you feel torque steer on the shift as well?
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Quote from: 16MagSport on May 16, 2017, 03:45:16 PM
What did the log show? Did the advance and/or throttle blade angle drop or swing wildly at the time, differently than a smooth shift? Sure sounds like wheel hope since it goes away with a softer shift. Did you feel torque steer on the shift as well?
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Hmmm, well... LMS doesn't eliminate all of the torque management, so at shift there is a torque source of 7 I believe? Don't have the logs in front of me.. but it's the source torque for shift modulation... but this is at every shift... Brad utilizes it as well since it takes care of adjusting spark at shift as well.. this is what Brad has mentioned to me...
Also, LMS uses the throttle to manage load, the the throttle does quite a bit of dipping through out a run... mainly I am sure to help with fuel pressure and boost spikes...
Honestly, besides the slightly extended torque source reading, and the quick period where the RPMs stay flat... nothing out of the ordinary...
But it doesn't feel like traditional wheel hop to me... the front end isn't bouncing around etc... it just stutters like it's not fully engaged in the gear...also does it once in awhile from 2nd to 3rd... and there shouldn't be wheel there...
I run BFgoodrich Sport Comp 2 summer performance tires...sticky tires...plenty of tread life...
Since I have done a KAM reset, driven it normally with the occasional WOT trying to give the learning portion time to catch up it has not done it....so I dunno... it's also much warmer so that could be a part of it...
Much warmer means the tires are softer. They'll hook harder but if they do spin it may be smoother. Pay attention to the road conditions too when it happens. Some roads are stickier than others. Did you have torque steer? I know my wife's Explorer hopped and would jerk with torque steer. That tune had all torque management removed and huge boost spikes. Brad's is nice and smooth. I like that because I can go WOT with the fam onto the highway and it is smooth and I don't get yelled at. If it was hopping and jerking, the wife would be a little upset. I was disappointed that it did this hopping. The damn AWD should keep that from happening. If it was locked in a 50/50 power split then it couldn't hop the front tires. I wish it wouldn't let the fronts spin faster than the rears when at WOT.
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Quote from: 16MagSport on May 17, 2017, 12:47:46 AM
Much warmer means the tires are softer. They'll hook harder but if they do spin it may be smoother. Pay attention to the road conditions too when it happens. Some roads are stickier than others. Did you have torque steer? I know my wife's Explorer hopped and would jerk with torque steer. That tune had all torque management removed and huge boost spikes. Brad's is nice and smooth. I like that because I can go WOT with the fam onto the highway and it is smooth and I don't get yelled at. If it was hopping and jerking, the wife would be a little upset. I was disappointed that it did this hopping. The damn AWD should keep that from happening. If it was locked in a 50/50 power split then it couldn't hop the front tires. I wish it wouldn't let the fronts spin faster than the rears when at WOT.
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No torque steer that I can remember. I am fully aware of the difference between cold tires/road vs warm tires/road...different types of asphalt etc...
Thanks!
The stutter feels like the car tries to switch gears but misses it (doesnt catch)on the first or second try. I know that's not very descriptive, but it's an awful feeling that makes you think something really bad is happening.
Quote from: TSS on May 17, 2017, 06:48:43 PM
The stutter feels like the car tries to switch gears but misses it (doesnt catch)on the first or second try. I know that's not very descriptive, but it's an awful feeling that makes you think something really bad is happening.
Yea, like your stop is gonna be a transmission shop...
Strange. If you didn't feel anything in the wheel then it wasn't hopping. Well, I would just run the softer shifting tune and not worry about it. Hopefully it just means that it is unhappy with that higher pressure. Makes you kind of wonder if the pressure should be dropped more for some safety margin.
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Quote from: 16MagSport on May 17, 2017, 10:23:09 PM
Strange. If you didn't feel anything in the wheel then it wasn't hopping. Well, I would just run the softer shifting tune and not worry about it. Hopefully it just means that it is unhappy with that higher pressure. Makes you kind of wonder if the pressure should be dropped more for some safety margin.
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Well... who knows right? I know they dial up the transmission shift speed and pressures to very edge... I believe that is self evident with some who can run it and some who can't...
If they are pushing it to the point where mechanical tolerance between builds makes a difference then maybe there is something to be said about running on the ragged edge...
BUT... if say 85-90 percent of the cars can run it without problems and there is enough advantage to running the tune that way... the other 10-15 percent are just gonna be anomalies you deal with...which means taking it to Ford to get a new transmission and/or PTU may NOT solve the issue..
For me personally there is NOTHING to indicate there is a mechanical deficiency in my car... no codes, fluids look good, shift great on other tunes or those with a slightly lowered pressure...
I will say with the rise in temps to an average of 70F along with the KAM reset I have not had an issue yet...
The stutter has been described as the car attempting to shift - not shifting - attempting to shift - not shifting and then shifting - all of this in a split second. It is a bit of a mystery why some cars do it with high shift pressure and some do not. It is also odd that in several cases, new fresh fluid eliminates the issue and in other cases, it has no effect.
As Todd and I have both confirmed, lowering the pressure to prevent it does not hurt acceleration.
Quote from: Brucelinc on May 18, 2017, 09:27:07 AM
The stutter has been described as the car attempting to shift - not shifting - attempting to shift - not shifting and then shifting - all of this in a split second. It is a bit of a mystery why some cars do it with high shift pressure and some do not. It is also odd that in several cases, new fresh fluid eliminates the issue and in other cases, it has no effect.
As Todd and I have both confirmed, lowering the pressure to prevent it does not hurt acceleration.
How fast is the shift being commanded if i may ask. I am at 200ms.. and am curious if 180ms is to much.
Quote from: TopherSho on May 18, 2017, 09:32:48 AM
Quote from: Brucelinc on May 18, 2017, 09:27:07 AM
The stutter has been described as the car attempting to shift - not shifting - attempting to shift - not shifting and then shifting - all of this in a split second. It is a bit of a mystery why some cars do it with high shift pressure and some do not. It is also odd that in several cases, new fresh fluid eliminates the issue and in other cases, it has no effect.
As Todd and I have both confirmed, lowering the pressure to prevent it does not hurt acceleration.
How fast is the shift being commanded if i may ask. I am at 200ms.. and am curious if 180ms is to much.
Ask LMS, they generally don't disclose their tuning parameters.
Ya know what :) i'm feeling cheeky so i will do just that :)
Hasn't someone logged an LMS tuned car? The LMS guy on another forum wouldn't divulge any info, but then again I don't think he knew anything. This was my take from him. It is a magic black box that none of us could understand what it does, so just plug it in and don't ask questions.
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I have logged my LMS tunes. Not sure if there is a a pid or DMR that captures that data... I can check...
Quote from: TopherSho on May 18, 2017, 12:14:50 PM
Ya know what :) i'm feeling cheeky so i will do just that :)
Bah, cheeky bastards deflected ;) .. no answer there :) .. my quest continues.
I don't think we get to talk to the tuners. LMS has them locked up in the back room and just has salesman go on the forums and answer questions. That is my take on it anyway.
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