C/K Man

Ford's new 10 speed TorqShift is something of a scale-up of their light duty (shared with GM) 10 speed automatic, but the new Allison 10 speed in the GM HD's is a different design. I have seen both of them

Try Rockauto.com, they still list MU1658 as a good number. Maybe they have some left?

Controller might be bad. I think the TopKick uses the same one the pickup trucks do.

The 6L transmissions (70/80/90) have their own internal transmission control module, which operates on a CAN/BUS network with the ECM (engine) and BCM (body) computers. There really isn't a good way to make that swap work right without spending a lot of money. The link in the earlier post is for replacing a 4L60 with a 4L80, both old style 4 speed automatics, and a good swap. Maybe you could trade that 6L80 for a 4L80? There is this: http://www.zerogravityperformance.com/product/tcm-2650-mechatronic-transmission-controller-6l80e-6l90e-6l50e/ No idea how well it works, but as you can see it is not cheap.

There are 4 actuators. The mode (defrost/dash/floor) is on the left side of the HVAC module above the accelerator pedal. It has a large cam on it to move the dampers. The left temp. actuator is on the bottom center of the HVAC module, above the transmission tunnel a bit to the right behind the lower sound insulator. The right side temp. actuator is on top of the HVAC module, roughly in line with the left (lower) temp. actuator. That one is tough to get to. The fresh/recirculate actuator is all the way on the right side above the fan housing. To get to that one you usually have to remove the right air bag and/or glove box depending on which dash you have. I have never experienced the problem you are having, my guess is that it is either the fresh/recirculate actuator or maybe the HVAC control module. I would take a look under the dash on the right side to see if a plastic bag or piece of paper got sucked up into the recirculate air intake.

I have not done it but I think those mirrors are the ones used on 3500 and 4500 cut-away vans. The doors on the 2003-2009 TopKIck/Kodiak are the same as the van doors, so it might be just a matter of installing the van mirror parts.

I don't think GM wanted to, but since the medium duty line was not very profitable at the time and GM going through bankruptcy the mediums had to go. I was told a short time after the TopKick and Kodiak were dropped, GM was already planning on re-entering the medium duty market. GM had planned on forming a joint venture with Navistar for medium duty trucks as far back as 2006, but Navistar was having their own problems. In 2015 the time was right for both GM and Navistar, and the Silverado medium duty and International CV series is the result. I am hearing rumors there are other (larger) projects being considered.

I am really starting to think the 6.6L is aimed at Ford's 6.2L. Both the GM 6.6 and Ford 6.2 are the standard engines, both only come with 6 speed transmissions. Maybe GM will eventually offer a larger gas engine with a 10 speed as an option.

I didn't think it was a bad performance for a gas engine. If I were towing that much weight regularly, I would get a 3500. Doubt it would sag as much in the rear with that much tongue weight. I hear from some sources that the 6.6L should be compared to the Ford 6.2L and Ram 6.4. Supposedly GM has a larger gas engine on the way.

Nice! Thought the area looked familiar, then I saw you got on the 15........

Looks like they are going to be popular. Saw 2 new ones working in the past few days. Have not see any of the International versions yet.

Charge light is likely to be turned on by the body control module. You should probably start with a scan tool and see what the codes are. It's funny that you have 14v. and the light is on.

Good question. I got a look at the 2020HD service manual, and most of the front suspension components look similar to the 2011-up GMT-900 and K2XX HD's. However, I did see some differences, sway bar end links for one. Of course, looking at pictures doesn't give you the whole picture! There very well could be enough minor changes to each part to make the whole suspension 'all new'.

Like I said, IF the Ford 7.3L shows any meaningful advantage over the GM 6.6L, it will be because of Ford's 10 speed transmission. I hear that currently work is underway on a version of the 6.6L for the new Silverado 4500/5500/6500 medium duties. It may be teamed with the Allison 2000 series, as the 6.0L L96 is in Freightliner chassis built for UPS and others. I wouldn't be surprised if it too caries a different rating than the L8T's in the 2500/3500, but remember these differences often are the result of how medium duty commercial vehicle engines are rated, not because of any real difference in the engines.

Noticed the Ford 6.2L continues with the Torq-Shift G 6 speed transmission. I have been hearing that since the L8T 6.6L is the standard engine in the HD pickups it should be compared to the standard (6.2L) V-8 in the Super Duty pickups, even though it is very close in output to Ford's new 7.3L.