2nd gear rpm swing feels notchy

mrtosh · Jul 19, 2012

I just picked up a 2012 Sport about 3 weeks ago and currently have about 850 miles on the truck. Love it so far but have noticed a strange notchiness to the rpm swing in 2nd gear. Almost like the rpm's hang for a second(generally around 2500 R's)and then pick up. The speedo doesn't appear to hang up. I only notice this under moderate throttle(maybe20-25%). Under any harder throttle load it swings fast through the revs like it should. It almost seems like the truck is deciding if it should shift or keep accelerating and it picks the latter. Anybody else notice this?

Thanks in advance!

mrtosh · Jul 19, 2012

I took a couple vids on the way to work this morning. In the first video it happens around 2600 rpm. In the second video around 3100 rpm.
https://www.youtube.com/watch?v=b6C625vOerY&feature=youtube_gdata_player
https://www.youtube.com/watch?v=mTK91Pax-cQ&feature=youtube_gdata_player

jlb · Jul 19, 2012

It looks like it has something to do with toque converter lockup because your speed keeps changing even when the tach hangs.

mrtosh · Jul 19, 2012

Normal operation on a truck with under 1000 miles? I'm taking it in to the dealer tomorrow and want a tech to ride along with a star scan tool hooked up. I'll post what he says.

jlb · Jul 19, 2012

Not really sure lol, this is the first truck I have ever had an automatic in, and I despise it so much I just put it in gear, and try to ignore the fact I don't get to shift...

mrtosh · Jul 19, 2012

Lol I know what you mean. Soo much computer controlled TCC lockup and torque management these days. Makes a 400hp hemi feel like a 4cyl Mazda.

Hollabakzach23 · Jul 19, 2012

Mine does the same thing in second gear only drops about 500 rpms but when i fully accelerate it gets on it just fine. I have a 98 though so not near as new. I have been told its just the torque converter and it's nothing to worry about though so idk.

Ramunit · Jul 19, 2012

Normal tc lockup.

mrtosh · Jul 19, 2012

Ramunit said:
Normal tc lockup.

Does yours do the same?

Lawhand · Jul 20, 2012

this is due to the new "6 speed" trans... 2nd and 3rd gear have only about a .2 ratio diff. so this means ushift between 2nd and 3rd gear but its not like going from 1st to 2nd or 3rd to 4th. I noticed mine would sometimes increase by 10mph without the engine turning over anymore than 2500 rpm. This is due to the gear change and close ratios. atleast this is what i believe the be the cause

garner · Jul 22, 2012

^Yupp! The 2012 use 2nd prime as an actual driving gear so the rpm drop very little when it shifts from 2nd to 2nd prime

bloombloom88 · Jul 23, 2012

garner said:
^Yupp! The 2012 use 2nd prime as an actual driving gear so the rpm drop very little when it shifts from 2nd to 2nd prime

What's 2nd prime mean?

jlb · Jul 23, 2012

In the previously tuned version, up to 2011 2nd prime was a downshift only gear for passing. I.e. the truck would never use it when it was counting up from a stop, only on the highway when you tromp on it to pass or something. It has a slightly better ratio for top end speed than 2nd.

garner · Jul 23, 2012

bloombloom88 said:
What's 2nd prime mean?

It's a gear between 2nd and 3rd used to reduce the dramatic difference between 2nd and 3rd gear. In 03-11 it was only available for passing on the highway or manually shifting. But in the 2012 it is used all the time

Lawhand · Aug 3, 2012

garner said:
It's a gear between 2nd and 3rd used to reduce the dramatic difference between 2nd and 3rd gear. In 03-11 it was only available for passing on the highway or manually shifting. But in the 2012 it is used all the time

yeah sometimes it makes me angry. my truck doesnt like 25MPH speed limits in my hood. makes weird groans in 2nd prime at 25 MPH. (mufflex exhaust sounds)

Ramunit · Aug 5, 2012

Just for the record 2nd prime started being used as a regular upshift starting in 06 so 03-05 highway kickdown only, 06-12+ regular upshift and downshifts but that is neither here nor there.

2nd gear rpm swing feels notchy

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