GM 6.0 gear searching.....

[ericpatt]

Help??

While this may have been covered to some extent on this forum or another, I'm looking for suggestions for my 2012 Suburban 2500 with the 6.0l engine.

Towing my boat(04 Nautique) it's awesome. Hardly know the boat is there.

However, when hauling our 30ft camper it's a different story. Camper weighs 6900lbs empty. Fully loaded it's probably close to 8000 not including wife, 3 kids, dog and misc stuff in the truck. Can't keep it 60-65 without it searching for a gear it "likes". I usually downshift manually but tach is constantly at 3k.

What to do? Love the truck. Kids are happy in back and plenty of space. Called a couple shops.
1 suggestion was to modify computer?
2 suggested cold air intake, tuner, & exhaust?

Does any of it work??

There's got to be something I can do. Slowing down only makes me feel like a traffic hazzard. Would like to be able to pull at least 65mph on the highway....

[dodge_guy]

What I would do is go to 4.10 (assuming you have 3.73`s) and get a tune from black bear performance. between the 2 you will wonder why you or GM didn't build it that way from the beginning!

[APT]

Fundamentally, if the transmission is changing gears or unlocking/locking the torque converter more than every 5 minutes, then limit the top gear to one lower. So if you are hunting between 4-5, then just stay in 4th. That 6.0L will last for 300k miles at 3000rpm under load. You will get better throttle response and probably better fuel economy in addition to reducing transmission wear.

Are you using the transmission's Tow/haul mode? If not, please do. GM also has the "M" mode which is really just a top gear range limiter vs. a manual mode. When I tow my TT, I use T/H plus M4 or M5 depending on the conditions. And like yours and your family, everyone else is happy watching movies, electronic devices, car games, etc and sometimes forget we are towing.

All 2008-2013 3/4 ton GM SUVS have 6.0L/6-spd/3.73. 65mph in 5th gear is about 2200rpm and 4th gear is 2800rpm. I tow at 65-72mph in 5th or 4th. My wife usually doesn't complain until the tachometer is over 4500rm, and my shoulder sometimes hurts if it hits 5500rpm. The truck is fine.

[kw_00]

Nothing wrong with the truck. Mine likes 3k as well in direct in 4th gear. Remember 5th and 6th gears are both OD. You can lock out gears by selecting the M mode. I lock out 6th when pulling and will run in 5th. Now when I leave Florida and head through the hills, I lock out 5th and stay in 4th. Pulls really well for hours at 3k but no worries, I would rather pull at that rpm then to have the engine struggle in 5th, that's not good for the engine at all. Puts a lot of stress on the bottom end. 3:73 is a great all around gear and when in 4th your ratio is like a 4:10. I pull 10k of fifth wheel with my 09 6.0. Gas engines by design have to rev higher then diesel. No issues in doing this. Engine not screaming, not going to blow up. 3k is half the rpm range, diesels run half there rpm range all day. Your power band aka TQ and HP are gaining around 3 k and up, GM VVTi comes in to play around that Rpm giving max efficiency and power. Cold air intake, waste of money from experience, gearing to 4:10 will give better performance but expensive. Custom tune EFI live via Blackbear Performance for 600.00 is a great investment in my experience. I have one myself and stock verse efi live tuning there is a difference. No worries at 3k rpm btw, less strain on engine components, truck is by design going to run this way. GM 6.0 HD engines, last, they are a proven workhorse and will work beyond there service life of 200K, hence fleets all across the states use them. I have seen many with 300k running like new. Friend of mine owns several and pulls sheds around also construction equipment for his company. He works his 6.0 really hard, no problems, runs all day and always has a load on them. Last one he just let go had over 300k on it... reason he sold it cause his tranny gave out, truck engine wise ran great and had lots of power. His new truck, well it's another GM 6.0. So if you ask my opinion go with a tune.....especially Blackbear, you willl like it!

[old_guy]

I have a 6.0 with 4.10's get bad gas mileage but the truck doesn't hunt like yours does. I put it into tow/haul mode and hit the road. I tow about 60 and I manually gear down for hills if it starts to slow down too mcuh for my eyes

[wnjj]

lawrosa wrote:

goducks10 wrote:
Change your rear end gears.

Dude he has a 6.0 and 3;73's... Its bad enough he gets 2 mpg...

Dont change rear gears... Just ride in 4th gear with that load as I stated above in my post...Use tow haul mode!!! Its that little button on the shifter handle..

I guess no one read my post and just reply for the heck of it..

2500 burbs with 6.0 all had 3;73 AFAIK.. and can tow 9000 plus...

Your post wasn’t there when I started mine so your rant about “no one” was just one guy. Changing gearing can be a good idea if the speed you want to travel the most frequently with the given load puts your vehicle between two gears, neither of which are ideal.

I agree the tow/haul and/or downshifting is a good and free first option.

[lawrosa]

goducks10 wrote:
Change your rear end gears.

Dude he has a 6.0 and 3;73's... Its bad enough he gets 2 mpg...

Dont change rear gears... Just ride in 4th gear with that load as I stated above in my post...Use tow haul mode!!! Its that little button on the shifter handle..

I guess no one read my post and just reply for the heck of it..

2500 burbs with 6.0 all had 3;73 AFAIK.. and can tow 9000 plus...

[goducks10]

Change your rear end gears.

[wnjj]

drsteve wrote:
What rear gearing? That is a pretty good load for the Burb. 3000 rpm is not out of line for the 6.0, it makes its best power around 4500.

Do you have tow/haul mode?

Ditto on the rear gearing question. If it just doesn’t quite stay in the higher gear you’d rather be in and easily pulls after downshifting, changing the rear axle to lower gears may be your answer.

[lawrosa]

ericpatt wrote:
Help??

While this may have been covered to some extent on this forum or another, I'm looking for suggestions for my 2012 Suburban 2500 with the 6.0l engine.

Towing my boat(04 Nautique) it's awesome. Hardly know the boat is there.

However, when hauling our 30ft camper it's a different story. Camper weighs 6900lbs empty. Fully loaded it's probably close to 8000 not including wife, 3 kids, dog and misc stuff in the truck. Can't keep it 60-65 without it searching for a gear it "likes". I usually downshift manually but tach is constantly at 3k.

What to do? Love the truck. Kids are happy in back and plenty of space. Called a couple shops.
1 suggestion was to modify computer?
2 suggested cold air intake, tuner, & exhaust?

Does any of it work??

There's got to be something I can do. Slowing down only makes me feel like a traffic hazard. Would like to be able to pull at least 65 mph on the highway....

There's nothing wrong and I wouldn't do anything.

1. You have the six speed... Tow in 4th gear if need to. You should not be screaming the motor at 65-70 mph. I have a 4 speed trans and I tow in 3rd....lol.. My rpms are not much over 2600 rpm. I do have 3;42 rear.

You have 3'73's and that's only a couple hundred rpm difference. 3000 rpm's is nothing.. You don't want gears to hunt... So lock it in 4th or 5th..

My 3rd gear is a 1:00 ratio. Your 4th gear is a 1;15 ration.. That's what I would tow in. All the other gears are overdrives.

2. You have tow haul mode. Use it. It will hold the gears longer. Use it and try it in 5th and 4th. If it starts hunting tow haul will/should keep it from shifting longer. You may get away with 5th gear @ a .85 ratio with the 3:73 rear...

3. All a tuner will do is the same thing the tow haul mode will do.. Change shift points. And the factory t/h mode also locks the torque converter sooner or as soon as possible to run the trans cooler.

4. Cold air kit??? Waste of money. You will net 0.... Nil.... You'll just be sucking hot engine air into the intake...

That 6.0 as well as the 5.3 like to rev... Towing the hills im up in 3500-4000 rpm territory...

Unfortunatly I get 9-10 mpg towing... I think the suburban with the 6.0 gets 10-14 not towing....

Good thing I think you have 39 gallon tank...


Moral???

4th gear, tow haul, and have fun. Watch the trans temps and dont let them get up past 200f too much or too long. Change filter and fluid in trans more often if towing a lot and trans gets hot. Ler er' REV!!!!!

[drsteve]

What rear gearing? That is a pretty good load for the Burb. 3000 rpm is not out of line for the 6.0, it makes its best power around 4500.

Do you have tow/haul mode?

[Grit_dog]

3k rpms ain't bad. It's normal that you'll have to pull in 3rd or 4th gear with that big of trailer and that engine.
A bunch of bolt on stuff will help a little bit not much. Gearing down is a better bang for the buck but not worth it really. Just let er eat with the trailer hooked up.

Sounds like another HD diesel SUV customer IF one of the big 3 would actually make one! The only real diesel SUVs have been out of production for so long they're all wore out. I can't believe a mfg hasn't jumped on this yet. Factory Duraburb or Excursion Diesel would sell like hot cakes ...