2016 Tranny Break-in Time

[ChrisTronyxYocum]

Got a new 2016 Silverado 1500 LT Z71 All-Star 6 Speed the middle of March and I'm wondering what the mileage usually is for the tranny to break in. I have ~3,100 miles on it now and if I let off the gas and just let the truck slow down I can feel the trans downshift and really drag the truck. More of a drag is noticed when I'm going up a hill, most noticeably when I'm going up the last hill before turning onto my street. Speed limit is 25 and I don't usually accelerate very quickly so I tend to just slowly accelerate going up the hill and it almost feels like the truck is struggling or having a tough time figuring out what gear it wants to be in. Also, if I'm turning onto a hill I don't like to do it quickly as it jerks the truck around and, with the trans drag, the truck will almost stop. I have been just trying to give it a little more gas, but nothing crazy, obviously, so that it doesn't happen. I just hope that it's not going to always be like this because I believe that it should be completely smooth. I shouldn't be able to really feel it shift like that and I don't think I should be able to use the downshift of the trans to slow me down like that. I mean, it's really noticeable as, when I'm braking, I have to left off the break a bit to accommodate for the drag of the downshift or it's like I just stomped on the brakes to brake-check someone. Not like the wheels are locking up or anything like that, but it all just seems a bit odd to me. It is my first new vehicle ever though so I've never gone through the break-in of anything other than my utility quad.

 

Just looking for some info and advice, especially if this is not normal behavior. Thanks in advance.

 

Chris

[sams819]

try holding in the tow haul button for 6 seconds to turn thr grage braking off. see if that helps.

[ChrisTronyxYocum]

Thanks for this, I will definitely try that. Didn't even know that was a feature. I thought that was a button beneath the HVAC controls? Wait, that's Hill Descent Control, right? Ok, so why would Grade Braking be on by default anyway? Shouldn't that enable if a trailer is attached and you start braking while going down a grade?

 

EDIT: Just checked the owners manual: "Tow/Haul Mode Grade Braking: Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul Mode is selected and the vehicle is not in the Range Selection Mode. See “Tow/Haul Mode” listed previously and Manual Mode 0 292. Tow/Haul Mode Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle. On vehicles with a gasoline engine, to disable or enable Tow/Haul Grade Braking within the current ignition key cycle, press and hold the Tow/Haul button for five seconds. When the button is released, the requested mode change is made. A DIC message is displayed."

[ChrisTronyxYocum]

That did the trick! Difference is night and day and now it drives exactly how I expect it to. My only issue with this is that it's been on since I bought the truck, despite me using Tow/Haul, which means it's not working properly, at least from my understanding of the wording in the manual. I just hope I don't have to turn it off every time I start the truck, but I'll see if it's on again when I start her up in the morning.

[TJay74]

You will have to turn the grade braking off every time you start the truck, it is considered a safety feature and is on by default.

[ChrisTronyxYocum]

Alright, thanks, but that's dumb considering the manual states otherwise and it seems to (I'm sure this sounds crazy) affect the acceleration from a dead stop too. With it off the throttle seems more responsive and the truck just feels like it moves better.

[ChrisTronyxYocum]

Alright, so after driving the truck more with the Grade Braking disabled, I can feel that this seemed to help some, but the issue is still there. Anyone think this is break-in related, just how the trucks are, or an issue I should have looked at with my warranty?

[scott19677]

Alright, so after driving the truck more with the Grade Braking disabled, I can feel that this seemed to help some, but the issue is still there. Anyone think this is break-in related, just how the trucks are, or an issue I should have looked at with my warranty?

 

 

Try driving in M5 manual mode. This will lock out V4 and you will really notice better drivability. Just pull the gear selector all the way down, a few clicks on the +/- button up to M5 and when you get on the interstate up click to m6 and this will shift into hi gear and activate AFM. I have had three of these new gen trucks and this will make the truck drive better until you decide to get a custom tune from someone like Blackbear. Trust me an ECM and TCM tune will make all the difference in the world. And don't buy into any of that "learn mode" crap the dealership will feed you. Although there is some amount of "learning" in these trucks the problem boils down to plain pure and simple piss poor tuning by GM. Until you get a tune you have no idea how good these engines and trannys really are.

[ChrisTronyxYocum]

 

 

Try driving in M5 manual mode. This will lock out V4 and you will really notice better drivability. Just pull the gear selector all the way down, a few clicks on the +/- button up to M5 and when you get on the interstate up click to m6 and this will shift into hi gear and activate AFM. I have had three of these new gen trucks and this will make the truck drive better until you decide to get a custom tune from someone like Blackbear. Trust me an ECM and TCM tune will make all the difference in the world. And don't buy into any of that "learn mode" crap the dealership will feed you. Although there is some amount of "learning" in these trucks the problem boils down to plain pure and simple piss poor tuning by GM. Until you get a tune you have no idea how good these engines and trannys really are.

 

 

Thanks Scott, I really appreciate it. I'll give that a shot on my way home tonight. I'm assuming that I should get click down to M5 once I exit the highway as well? I am planning on getting a BB tune ASAP, but I just have to save up the money for it.

[ChrisTronyxYocum]

Alright, so driving in M5 during city driving definitely makes the truck feel way more responsive, but the drag of the trans is still there. It's most prominent when it downshifts from 2nd to 1st.

[scott19677]

Yeah, I can't put my finger on the "drag" issue unless maybe it is just the close ratio gearing that these new trannys have. You didn't say what vehicle you drove before this one. It might just "feel" a lot different than your last truck. I'm on my third 2014 and I will tell you that my 2012 Z71 rode and drove a lot better than the K2's. Hell my 2007 with a 4.8 felt better than any of my recent trucks. Now Im not saying these trucks are bad, they just feel a LOT different. Try this, go to a dealer close by and test drive a LTZ or a Denali see if they drive differently. I would bet even your dealer would let you take a loaner out for a few hrs. Especially if they think(wink,wink) if you're thinking about trading up.

[ChrisTronyxYocum]

Thanks Scott. I came from a 2006 Dakota v6 that had 0 power, but it didn't shift hard or anything. I'm wondering if the 6 speed versus the 4 speed is making that big of a difference, not to mention the 11 years worth of technology differences. Might just have to try that with my dealer and see how another truck feels.

[scott19677]

Thanks Scott. I came from a 2006 Dakota v6 that had 0 power, but it didn't shift hard or anything. I'm wondering if the 6 speed versus the 4 speed is making that big of a difference, not to mention the 11 years worth of technology differences. Might just have to try that with my dealer and see how another truck feels.

 

 

Yeah, I think don't you have anything to worry about. I'd be willing to bet you got yourself a perfectly fine truck. Reminds me of when I wouldn't wear any jeans in the 80's except for Levi's and then you buy a brand new pair, you know the stiff,dark blue ones that I'd have to soak in the bath tub for two days just to start the break in period. These 6 speeds are really stout and well built and can handle a lot more power than what these trucks make and as in the words of Donald Trump,"BELIEVE ME" a tune will really make driving it a lot more enjoyable. Read a post below that I started in Feb of 2014.

 

http://www.gm-trucks.com/forums/topic/158104-feels-like-transmission-is-slipping/?hl=feels+like+transmission+is+slipping

 

Sooo....once you feel like everything is fine and rule out any real issues you need to get a good tune. I can personally recommend BlackBear Performance. Just search around on GMTrucks and I guarantee you won't find a single poor review. I hear Diablo is good as well as a few other tuners but I love mine. BBP will get that thing purring like a kitten. More power? Yeah a little, but the real payoff is the TCM tune. I had the in person tune and Justin rides around with you with his laptop and does the tune on the street and he can really dial the TCM tune in just how YOU like it. I have a pretty aggressive TCM tune with higher line pressure, higher shift points, raised max speed to I think 130mph, and then with the ECM I had him tune for 93/E85,pretty aggressive with the timing advance and raised warm idle RPM to about 650 RPM and I can tell you for a fact that on E85 my little 5.3 has surprised more than one Eco boost Ford and Ram, especially when you do hard launch in Auto4wd. But the best characteristic with the trans is that it does what YOU want it to do instead of it having a mind of its own. You know 'kinda like when you are driving a 4 or 5 speed clutch car and you are just cruising in say third gear and you just want to tip into the throttle and "lug it" in third and not downshift. Make sense? The stock TCM tune you can be in say third or fourth gear and if give it just a bit too much throttle and BAM! downshifts to first gear, then you let off because you just hit the rev limiter and then the trans just gets stupid for lack of a better word. UGH!!

That used to drive me nuts. But now It really couldn't be any better than if it had a clutch. Now if only BBP could fix the drivers seat in my truck. I absolutely hate these seats. Keeping my fingers crossed for the 2018/19's. haha

Good luck.

[ChrisTronyxYocum]

 

 

Yeah, I think don't you have anything to worry about. I'd be willing to bet you got yourself a perfectly fine truck. Reminds me of when I wouldn't wear any jeans in the 80's except for Levi's and then you buy a brand new pair, you know the stiff,dark blue ones that I'd have to soak in the bath tub for two days just to start the break in period. These 6 speeds are really stout and well built and can handle a lot more power than what these trucks make and as in the words of Donald Trump,"BELIEVE ME" a tune will really make driving it a lot more enjoyable. Read a post below that I started in Feb of 2014.

 

http://www.gm-trucks.com/forums/topic/158104-feels-like-transmission-is-slipping/?hl=feels+like+transmission+is+slipping

 

Sooo....once you feel like everything is fine and rule out any real issues you need to get a good tune. I can personally recommend BlackBear Performance. Just search around on GMTrucks and I guarantee you won't find a single poor review. I hear Diablo is good as well as a few other tuners but I love mine. BBP will get that thing purring like a kitten. More power? Yeah a little, but the real payoff is the TCM tune. I had the in person tune and Justin rides around with you with his laptop and does the tune on the street and he can really dial the TCM tune in just how YOU like it. I have a pretty aggressive TCM tune with higher line pressure, higher shift points, raised max speed to I think 130mph, and then with the ECM I had him tune for 93/E85,pretty aggressive with the timing advance and raised warm idle RPM to about 650 RPM and I can tell you for a fact that on E85 my little 5.3 has surprised more than one Eco boost Ford and Ram, especially when you do hard launch in Auto4wd. But the best characteristic with the trans is that it does what YOU want it to do instead of it having a mind of its own. You know 'kinda like when you are driving a 4 or 5 speed clutch car and you are just cruising in say third gear and you just want to tip into the throttle and "lug it" in third and not downshift. Make sense? The stock TCM tune you can be in say third or fourth gear and if give it just a bit too much throttle and BAM! downshifts to first gear, then you let off because you just hit the rev limiter and then the trans just gets stupid for lack of a better word. UGH!!

That used to drive me nuts. But now It really couldn't be any better than if it had a clutch. Now if only BBP could fix the drivers seat in my truck. I absolutely hate these seats. Keeping my fingers crossed for the 2018/19's. haha

Good luck.

 

Wow Scott, that is a TON if awesome information. Thank you! I am definitely going to get the BBP ECM & TCM tune, and would LOVE an opportunity to have an in-person one done, but it all depends on timing and location, etc. Definitely going to increase the idle RPM, probably to the same that you did of 650 as it the needle tends to sit JUST below the 500 line right now.

 

I've been running 89 in the truck since I got it and I've been wanting to try out the E85, but there aren't very many stations around me that have it, which is what brings up this concern; the closest E85 station is near my work, which means I may not always be able to (or feel like) driving there to get fuel. Can I switch between and/or mix E85 with 89 or is it that once you switch to E85 that's all that you should/can run?

 

BTW the M5 city, M6 highway has made a huge difference in how the truck runs and performs, and I've even seen a bit of an increase in my fuel mileage in the last few days since I started doing that. Thanks again for that bit of advice.

[scott19677]

It's not suggested to switch back and forth frequently. You won't hurt anything, just will not get any real gains. You will want to run tank as low as possible before FILLING UP with e85. Then drive for about 10 miles before shutting the truck off. This lets the truck recalibrate for e85. Even still you will not get maximum gain till probably the 2nd tank. But 25 to 30 hp is very easy to get. Now it won't feel like a pro mod but the best way to describe it is the truck feels ..."snappy or sporty"? A few things to keep in mind. With e85 your mpg will take a pretty hard hit but this is usually offset by cheaper price. Also I tend not to run it in winter for a few different reasons. There is a very good thread on e85 on here if you do a search for it. And one little thing you might notice is that on cold start you could notice the engine might take a few more cranks to fire up,this is normal and nothing to worry about. But my truck with a tune,k&n,exhaust and e85 has snuck up on and spanked more than one 6.2 who I assume we're stock.lol Just keep your eyes out for a High Country and smoke em. That is unless they have the same mods and then it's kinda embarrassing. Haha Sorry man but I gotta go I'm on my phone as I cannot get to my desktop computer due to a knee replacement Fri morning. Thank God for Percocet. But as far as e85 try it you'll like it if the price difference works out in your area. Good luck