C/K Man

Ford the record, the 10 sped automatics in the GM 1500's are similar to the 10 speeds in the F-150. Those were the jointly developed RWD 10 speed automatics. The 10 speed HD Torq-Shift for use in the Super Duty is a 'scale up' of the joint venture 10 speed, similar design but larger for increased capacity. The 10 speed Allison 10L1000 is not related to the joint venture transmissions or the 10 speed Torq-Shift. GM did that one themselves with help from Allison. Notice that the base model F-250 Super Duty still uses the 6.2L gas V-8 with the old 6 speed automatic from the F-150 (named Torq-Shift G). For that reason I think that GM may want to keep the 6L90 behind the L8T as the base HD powertrain to keep the price down for fleets. Offering the Allison 10 speed as an option with the L8T may make some non-commercial customers happy if it comes with better performance and economy. Also some have pointed out that the 7.3L is the optional gas engine in the Super Duty, while GM does not offer a larger gas engine as an option. There were rumors of a larger gas engine for commercial trucks, perhaps something is coming for the HD pickups as well. If so, I think it would be a sure thing that a larger gas engine would come with the Allison 10 speed.

Good question. For me the L8T 6.6L/6L90 drivetrain would be fine. I particularly like the fact that the 6L90 is a proven reliable transmission that shifts well and is not 'busy' like a lot of 10 speeds. Have not heard anything bad about the Allison 10 speed, but on 'Ford-Trucks.com' there are a lot of negative comments and experiences with the Ford HD 10 speed, particularly with the 7.3L gas.

Just bought a new one for my wife. Not bad at all, plenty of power, looks nice, good size.

Looks like Chevy will introduce a heaver version of the 6500XD LCF for 2021. The new 7500XD will feature a 33,000lbs. GVW.. Believe it of not, still with the Isuzu 5.2L 4 cylinder diesel.

2011 should be an L96. Yes, knock sensors are on the either side of the block, right between the starter and engine mount, left between the oil cooler lines and engine mount. They may have thermal insulators covering them. Much better location, they seldom give trouble since GM moved them.

Someone was saying the 2021 HD chassis was going to an E coat/paint process, but I never heard it mentioned anywhere else.

Any word or rumors about 2021 HD changes beyond what we have seen in the order guides? I am not expecting much, but I think 2022 may bring an MCE.

Having that issue on our new 6500's as well.

This is not a big deal. 'Monitors' are basically self tests the engine computer performs on certain components. In order to run all the tests, the truck has to be driven through various cycles of warm up, acceleration, deceleration, and steady cruise. Usually these self tests will all run in a day or two of normal driving.

I am not sure you would even need one on these modern DI engines, the crankcase ventilation system has oil separators built right into the valve covers. If someone did rig up a catch can on a new 6.6L L8T, it would be very interesting to see if any oil ended up in it.

Best of luck to you, it really isn't that hard to make the ABS work right. As for the previous owner, it never ceases to amaze me how much time and effort someone will put into fixing something the wrong way.

2007 4L80E 4 speed automatic was replaced by 6L90 6 speed automatic. 2007 6.6L also got VVT. New chassis, front axle and suspension in 2011. I think 2011 and newer is better if it's in your price range.

My understanding is the 6.6L has the oil/air separator built into the valve covers like the DI 4.3/5.3/6.2 engines do. I don't think a 'catch can' in needed.

I would want to see fuel pressure under load. Might be dropping off on you. Check fuel trim with a scanner, see if it's running lean.

The 8L+ engine rumor started about a year ago, was widely reported but have not heard anything lately. My guess is that it's a commercial engine. The 6.6L is going into the LCF 3500/4500 Isuzu based trucks. Nothing about a gas engine for the Silverado medium duty yet.