Transmission weird behavior

[outdoorphotog]

At 22k with a Roush tune, I have noticed since I went from the OEM sport wheel 17" tires to the Goodyear Ultraterrains 265/70/17, the transmission shift points in "D" seem pretty aweful and the transmission gets easily confused. Around 50mph, it will go from 9th gear to 10th, almost everytime i do a small gas pedal touch. 10th feels like its lugging at 1,400rpms or so at 50mph. Also going up hills in "D" it just seems to try and stay in the highest gear possible almost lugging up hill, its pretty bad. "S" seems to improve the uphill and flat land behavior, but on the steep downhills "S" causes 4,000rpm which just sounds bad, and ill have to shift to "D" to keep the revs down on a downhill.

The only other thing is i recently took a new job with almost 6000 ft of combined elevation gain in the morning (over 3 mountain ranges), and quite a bit less on the way back.

Recently I did a trans flush with Mercon ULV, it is back up to the correct level which is 4-5 at 207F-215F. I dont know if its better or worse since I have done that but feels about the same.

Anyone had similar issues in "D" they were able to resolve?

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[AdamHarris]

At 22k with a Roush tune, I have noticed since I went from the OEM sport wheel 17" tires to the Goodyear Ultraterrains 265/70/17, the transmission shift points in "D" seem pretty aweful and the transmission gets easily confused. Around 50mph, it will go from 9th gear to 10th, almost everytime i do a small gas pedal touch. 10th feels like its lugging at 1,400rpms or so at 50mph. Also going up hills in "D" it just seems to try and stay in the highest gear possible almost lugging up hill, its pretty bad. "S" seems to improve the uphill and flat land behavior, but on the steep downhills "S" causes 4,000rpm which just sounds bad, and ill have to shift to "D" to keep the revs down on a downhill.

The only other thing is i recently took a new job with almost 6000 ft of combined elevation gain in the morning (over 3 mountain ranges), and quite a bit less on the way back.

Recently I did a trans flush with Mercon ULV, it is back up to the correct level which is 4-5 at 207F-215F. I dont know if its better or worse since I have done that but feels about the same.

Anyone had similar issues in "D" they were able to resolve?

Your truck is acting very normal. Let that trans do it’s thing and don’t overthink it. Might have to adjust that tune. Don’t do any more flushes either.

Also, I’m confused about your drive. Does the phrase “what goes up must come down” not apply to your commute? Lol

 

[AZRanger]

My commute is mountainous as well and it does lug going uphill. Transmission is always shooting for high gears. Sport mode helps or locking high gears out.

 

[outdoorphotog]

Your truck is acting very normal. Let that trans do it’s thing and don’t overthink it. Might have to adjust that tune. Don’t do any more flushes either.

Also, I’m confused about your drive. Does the phrase “what goes up must come down” not apply to your commute? Lol

Well it makes me feel better I think. Its a confusing series of up and down mountains, but the return drive is much more downhill.

 

[outdoorphotog]

My commute is mountainous as well and it does lug going uphill. Transmission is always shooting for high gears. Sport mode helps or locking high gears out.

That does sound very similar, am glad to hear it.

 

[Fomocodt]

Take it in and most likely they will reset it and perform an adaptive relearn. I did that to mine as it had a very harsh shift in and out of 4th on medium accel.

i reset it and did adaptive drive cycle and its good to go. We also see a few bad valve bores from time to time in the main control. Ive done about 5-6 this year in various model 10r80s

 

[Frenchy]

Something to understand. The tires you put on are most likely heavier and due to being bigger the speed to RPM will be different. This is normal. Now the fact you have a tune does help in general. When I went from 265/70-17 to 285/70-17 I felt my truck being a little slower for the same reasons. If anything make sure you have the speedometer corrected.

 

[outdoorphotog]

Something to understand. The tires you put on are most likely heavier and due to being bigger the speed to RPM will be different. This is normal. Now the fact you have a tune does help in general. When I went from 265/70-17 to 285/70-17 I felt my truck being a little slower for the same reasons. If anything make sure you have the speedometer corrected.

I did correct it in FORscan but I havent felt much change

 

[Frenchy]

I did correct it in FORscan but I havent felt much change

Unless you opt for a different tune like Livernois things will basically be the same. Not much else to so here. Understand that the 10R80 is a whole different animal in its own class when it comes to Automatic Transmissions.

One thing you can also do if no one else has mentioned it yet is put the truck in Tow mode. Yes that is right!! Even without a trailer in tow!! What is it going to do? Basically be a little bit more load sensitive and keep you in a more optimal gear for pulling loads even though you wont be pulling a load. Many including myself do this and have not had any major problems that I myself am aware of.

 

[outdoorphotog]

Unless you opt for a different tune like Livernois things will basically be the same. Not much else to so here. Understand that the 10R80 is a whole different animal in its own class when it comes to Automatic Transmissions.

One thing you can also do if no one else has mentioned it yet is put the truck in Tow mode. Yes that is right!! Even without a trailer in tow!! What is it going to do? Basically be a little bit more load sensitive and keep you in a more optimal gear for pulling loads even though you wont be pulling a load. Many including myself do this and have not had any major problems that I myself am aware of.

Nice, ill try this out tomorow morning.

 

[evoaire]

To tow, or not to tow? Yes that is the question.

 

[Motorpsychology]

Your truck is acting very normal. Let that trans do it’s thing and don’t overthink it. Might have to adjust that tune. Don’t do any more flushes either.

Also, I’m confused about your drive. Does the phrase “what goes up must come down” not apply to your commute? Lol

...And against the wind both ways.
I used to do that when I drove OTR semi. I was usually empty or lightly loaded, heading for a pickup west of Salt Lake City I-80 has a lot of steep grades over the Wasatch Range from the Wyoming boarder thru Park City and down into Salt Lake; no problem, light. Returning eastbound, I would go north on I-15/US89 to I-84 and rejoin I-80 at Echo, UT. It was 10 miles longer but took about the same time, as that route was much flatter and easier on the rig- oil & coolant temps would both camp just outside of their red zones.

 

[canyonslicker]

For what it’s worth every time I see someone doing a trans flush on this forum to help a problem it only exacerbated the problem…

Maybe rethink the problem from a different angle… the obvious is not necessarily the answer. You may be treating a symptom and not the cause.

 

[outdoorphotog]

For what it’s worth every time I see someone doing a trans flush on this forum to help a problem it only exacerbated the problem…

Maybe rethink the problem from a different angle… the obvious is not necessarily the answer. You may be treating a symptom and not the cause.

I just put a PPE pan on and the fluid had to be changed because of that. It was not done to "throw parts" at trying to solve any issues.

 

[Big Blue]

I just put a PPE pan on and the fluid had to be changed because of that. It was not done to "throw parts" at trying to solve any issues.

Just a question, why did you put the PPE pan on? Was it to fix a problem you were having, or was it to avoid a problem you think you might have? Or was because it looks cool when your under your truck? Just wondering why someone would crack open what is an essentually factory sealed highly complex unit, with a 150K mile recommended service interval. Possibly voiding its warranty.

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