I am a newbie but I will attempt to answer.
I received a great deal of help from forum member
@springer1981 and
@Retiredwarhorses when I was moving from a TH400 to a 4L80 and he steered me to the US Shift.
To answer your questions:
- Has anyone used a US Shift Quick 2 in their HMMWV?
I choose the Quick 4 instead based on the recommendation of
@springer1981 and because it have more features. Also, at the time, I asked them if they had the capability for a remote display and they said there was coming out in 2023 for the Quick 4, but that never happened. I buried my Quick 4 so I cannot see the display and I think it would be great if I could. The display would be useful to see, but I never had to tweak anything in the year I had it installed. I did have to use a laptop to tweak the tune via USB once.
- If you tried the Quick 4 did you actually use a custom tune or stick to the diesel tune?
I used the tune that US Shift diesel provided but I had problems where going from 45 down to 30, the tranny would stay in 4th gear and the engine would bog big time. I had to carefully studied their instructions, and made sure I saved the stock tune they provided and it was not terribly hard to tweak the tune to have it downshift out of 4th at a lower MPH. That is the only tweak I had to do in the year since I installed it.
As long as you save the stock tune, even if you mess up the tune big time at least you can put it back easily. You just need a windows laptop with a USB.
- How hard are these to connect?
It was not hard, but I have done a lot of electrical in my day. They state to run the power/ground direct from the battery so I did what they instructed instead of taking a shortcut. I purchased the harness from them and power and ground are simple enough. Their harness was of high quality
What is not simple is removing and relocating the Throttle position sensor. You have to remove a pin from a plastic cam on the throttle and install a GM TPS in it place. It is darn near impossible, but others said they can do it. I used a old soldering iron to melt the plastic cam, that you no longer need, and getting the pin out is then easy.
I used the original TPS and rigged up some real jerry rigged stuff to relocate it at the back on the engine. The original TPS is used for Fording and fan disengagement. It was a real PITA. You can buy a $300 setup that is prefabed for this purpose if you enjoy paying the HUMVEE tax.
Installing and wiring up the new TPS on the throttle was not hard. Calibration was not hard either, but I remember that I did have to adjust the TPS to get a minimum amount of resistance when the throttle was at rest. I just dropped the small screws a gazzillion times installing the new TPS and they beamed up into outer space!
- Where did you run the wires up?
I drilled a small hole near the shifter and then filed off the burs and used a grommet so the wire would not chaff. All the wires were wrapped in a sheathe so they don't look bad. I also sealed it with some solicone so water was less likely to infiltrate. But all these wires are hidden by a rudimentary console I built.
If you don't like to see wiring, you might consider a dash mount for the controller and run it up there instead.
- Did you remove the factory TCM after installation?
I did not have a factory TCM to begin with. Or if the TH400 did - I did not know enough to remove it!
One other thing unexpected on mine. I could not get the stock speed sensor to work on the stock odometer after the swap. Not an issue of the US Shift unit itself. Actually, if I had the display visible, which I don't, the vehicle speed is clearly displayed there. So I went the easy way out and installed a GPS speedometer instead.
Good luck with this.
If you have any questions, you can PM me and I will try to remember an answer for you.
