Jump to content

So, whats the fat and skinny on the 6spd GM puts behind the, 6.0 gasse


Recommended Posts

Somewhat holding out for GM to update the old 6.0 in favor of a 6.2/8speed.

 

Should that not happen, im going with a 6.0 gasser.

Question : What 6spd are they using? What hp/tq is it rated to? Any well known issues with them thus far?

 

I saw the Gauntlet vid where they ran it up the mountain side, and it didnt seem to want to drop to a lower gear. Held the higher gear, and bogged the while way.

No doubt, GM will likely do an update tune to correct this.

Link to comment
Share on other sites

Doubt there will be a tune or calibration as if they go to the 8L90, the two extra ratios in the gear spread will account for the gap in the 6L80/90 gear spread. 6L90 is the transmission, been in use in HD 6.0 trucks since 2007 redesign. Pretty much bulletproof. Less busy shifting than a 1/2 ton with the 6L80 as it will hold gears untill certain speeds and shift up when necessary. Example, when doing 35-40mph around town, empty, it will hold in 4th or 5th gear, where a 1/2 ton will go to 5th or 6th and fire up the AFM and then when you need to pass or do something there is a slight delay, AFM turns off and the trans drops like 2 or 3 gears. The 1/2 tons want 6th as soon as possible, where the HD trucks do not.

 

The 6L90 is a heavy-duty version of the 6L80 six-speed automatic, with a strengthened input gearset that has two additional pinion gears (six in total) and a strengthened output gearset that uses wider gears than the 6L80. Its flexibility extends to the clutches, where the 6L90 has one more clutch plate in each clutch than the 6L80 for heavy-duty applications. There is also a 6L90 version without the additional clutch plate to more closely match application requirements, where appropriate.

 

The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the 6L90 is 35 mm longer than the 6L80 case. The 6L90's case also accommodates additional fasteners between the transmission and the transfer case for improved driveline noise/vibration performance.

 

 

452 bhp max engine power, 531 ft.lbs max torque gas truck.

 

555 bhp max engine power, 550 lb-ft max torque pass. car.

 

Gearbox torque rating 885 lb-ft.

 

It is used in 2500 Suburbn/Yukon XL, Express/Savana gas and diesel, Silverado/Sierra HD gas, Cadillac CTS-V, and Camaro ZL1.

Edited by newdude
Link to comment
Share on other sites

In the Ike Gauntlet videos manual mode isn't used in the transmissions, that can highlight some serious programming problems but doesn't necessarily show what a truck is capable of doing. For the manufacturer it's a balancing act, programming a transmission to do well in an extreme uphill tow scenario, would make for a miserable driving experience on flat ground or moderate rolling hills.

 

In the 2500 gasser video the truck was maxed out, overall it was an impressive run. It's moving a lot of weight at high altitude, it's maintaining enough speed that its not a rolling hazard or at risk of getting in a wreck with an 18 wheeler.

Link to comment
Share on other sites

Doubt there will be a tune or calibration as if they go to the 8L90, the two extra ratios in the gear spread will account for the gap in the 6L80/90 gear spread. 6L90 is the transmission, been in use in HD 6.0 trucks since 2007 redesign. Pretty much bulletproof. Less busy shifting than a 1/2 ton with the 6L80 as it will hold gears untill certain speeds and shift up when necessary. Example, when doing 35-40mph around town, empty, it will hold in 4th or 5th gear, where a 1/2 ton will go to 5th or 6th and fire up the AFM and then when you need to pass or do something there is a slight delay, AFM turns off and the trans drops like 2 or 3 gears. The 1/2 tons want 6th as soon as possible, where the HD trucks do not.

 

 

452 bhp max engine power, 531 ft.lbs max torque gas truck.

 

555 bhp max engine power, 550 lb-ft max torque pass. car.

 

Gearbox torque rating 885 lb-ft.

 

It is used in 2500 Suburbn/Yukon XL, Express/Savana gas and diesel, Silverado/Sierra HD gas, Cadillac CTS-V, and Camaro ZL1.

 

I thought this was the first year GM had a 6spd behind the 2500 gassers.

Wasnt it a 4spd in the last body style?

Link to comment
Share on other sites

I thought this was the first year GM had a 6spd behind the 2500 gassers.

Wasnt it a 4spd in the last body style?

 

2007 when they redesigned was the first for 6L90. Last year for the 4L80 was the 2007 Classic body trucks. Last 4 speed offered in a GM pickup truck was the 4L60 with the 4.3 and 4.8. Express/Savana still use the 4L60.

Link to comment
Share on other sites

  • 3 weeks later...

In the Ike Gauntlet videos manual mode isn't used in the transmissions, that can highlight some serious programming problems but doesn't necessarily show what a truck is capable of doing. For the manufacturer it's a balancing act, programming a transmission to do well in an extreme uphill tow scenario, would make for a miserable driving experience on flat ground or moderate rolling hills.

 

In the 2500 gasser video the truck was maxed out, overall it was an impressive run. It's moving a lot of weight at high altitude, it's maintaining enough speed that its not a rolling hazard or at risk of getting in a wreck with an 18 wheeler.

I agree with this 100% in fact, if you compare it to the run they did with the Dmax, the gasser looks even more impressive, it came in at only 2mpg more in fuel consumption, and only took 2 minutes longer to complete the run, on a naturally assperated engine at 10,000 feet! I can't wait to run my new gasser in the mountains with our trailer behind it. It's a 11,000 lbs bumper pull toy hauler, and I'm expecting a huge difference compaired to the ol '96 3500 it's replacing.

Link to comment
Share on other sites

Yeah, that was pretty impressive considering the Dmax is getting air shoved down it's throat while the 6.0 was gasping for air at high altitude like an asthmatic. 6.6 Dmax took about 8 minutes to run the Gauntlet and got 4 mpg while the 6.0 took 10.5 minutes and got 2.5 mpg. Both of them smoking the Ram 6.4 2500.

Link to comment
Share on other sites

To add even more to this,the Ram 2500 6.4l hemi test was an interesting outcome too. the GM truck was able to do the test with way better results! one more reason for why I will always be loyal to the General

Link to comment
Share on other sites

I would like to see how well the gasser would do on the gauntlet if they used the manual mode. With my old 2012 1500 towing a 5000 pound trailer, I always used manual mode on big hills.

 

I will be towing my new 10,000 pound camper with my Sierra 2500 6.0 on its first long run this weekend. Maryland to Alabama. Looking forward to seeing how it does.

Link to comment
Share on other sites

I would like to see how well the gasser would do on the gauntlet if they used the manual mode. With my old 2012 1500 towing a 5000 pound trailer, I always used manual mode on big hills.

 

I will be towing my new 10,000 pound camper with my Sierra 2500 6.0 on its first long run this weekend. Maryland to Alabama. Looking forward to seeing how it does.

If you remember, throw some feedback on this thread please. I'm fairly confident that using the manual mode with any degree of skill will result in even better results. I appreciate their mode of testing though, remove as much error as possible from the test and run it purely on the merits of the OEM design and programs. Edited by rocnrol
Link to comment
Share on other sites

The stock trans tuning will do the same as manually shifting, if it can safely downshift it will, it simply bogs down enough until it can downshift without over revving the motor. Use tow/haul and enjoy the trip.

The manual mode definitely helped on hills with my old 1500. The truck would stay in 4th way too long until you lost all your speed and then it would downshift. If I put it in manual, I could get it in 3rd earlier and not lose all the momentum. Like I said, we'll see how the new 2500 does this weekend.

Link to comment
Share on other sites

With my 1500, manual mode most times could beat out anything that the stock programming would do. The 6.0L and 6L90 combo, GM didn't play CAFE number games with it. The programming and shift points are definitely serious with this setup. Go ahead a try the manual mode, but before you do, use the tow/haul mode so you have a baseline to compare results.

Link to comment
Share on other sites

We have several regular cab Dually's for work with the 6.0. They are used for towing and at roughly 110-130k we blew every single transmission on our 2011 trucks. We thought it might be related to the model year but just this week we had one go on a 2014 at 120k. They have all been well maintained so not sure if this is normal or if there is a problem when they are given heavy use for most of their life. We have a rep out inspecting the 2014 and hope they will step up to assist with the repairs. Up until they went out they worked great..As a personal use vehicle with just occational heavy use, they probably are probably are bullet proof. What GM needs to do is offer the Allison with the 6.0 as an option for those that use these trucks for commercial purposes.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.