I am having problems with my OD. I have a 4r100 on my PSD and it is coupled to the NV271 Transfer Case I was wondering.... The original owner said since he had it installed, he had to manually shift the trans. It seems to me that the installer installed it wrong. But he said that it worked for over 120000 mi. I can't seem to figure it out. I get Auto Shift light whether the switch is in man or auto. Actually in man mode it gets the auto light when you click the od switch over. Need input or a diagram of what goes where. Thanks.

 

I just installed a GV in a 95, and I should have the install stuff around somewhere. If the installer didn't tap into the speedo wires, it won't know how fast you are going to automatically engage the overdrive. It should engage at approx 47mph when in autodrive. Not sure what year you are dealing with, but on the 95, the speedo is driven off of the sensor in the rear. The connection with the GV controls is made by tapping into a wire on the computer. I did it right at the computer on the driver's firewall. GV even supplies bullet connectors for making the splice.

If the overdive itself works, this is the only thing I can imagine could be funky. You may want to call up GV. They are usually pretty helpful. They were even willing to send out another unit when we had one not engaging once upon a time. Luckily it got happy before it came to that, but they did offer. They never did have a reason for why the clutch stuck.

Anyway, I'll look for the diagrams when I go back to work monday.

 

Tim,
1. If you want to split all the gears, you have to do it manually, there is no automatic gear splitting.

2. The position of the rocker switch determines what mode it is in, not the red or green lights.

Example: Put the switch in AUTO and it will turn on the red light and the O/D will kick in once you have reached a pre-set speed. (About 40 to 45 mph depending how it has been programmed for you). It will then be in overdrive for all the rest of the upshifting gears. (Likewise, when the transmission downshifts to a lower gear, it will be that gear + O/D.) When it drops into o/d the red light will switch to the green, and you will feel a pretty solid thump if you don't back off the gas a little. Once you slow down to about 10 mph it will drop out of O/D and the red light comes back on.

If you are operating in MAN, you have to actuate the switch (mine is on the floorboard) manually to engage or disengage the O/D. You have to do this every time you upshift for each gear you want to split. It's a bit tricky to do it and be able transition smoothly from one gear to the next. I only split when I tow.

When you manually switch it out of O/D the red light will come on. It will turn off only if it takes itself out of o/d by slowing to less than 10 mph.

The original owner probably meant to say you have to manually shift the Gear Vendor transmission, not the 4R100. It will shift automatically, and there is no may to prevent that no matter how the GV was installed.

Hope this will help.

 

Nope the truck itself has issues 2nd and 4th don't work (I now how found the answer).