Thanks for the pics. I should be able to figure out the switch setup. I will probably just order a switch from GV, I don't want to spend much $, if the thing is dead anyways, but I don't want to short it out by trying to rig a switch to possibly the wrong wires. Worst case, I will just run a toggle straight to the solenoid and bypass the system. I really just want the OD for highway.

6" of snow on the ground this morning...maybe I'll get to it in a day or two now.

I did read about fluids...
The Oil recommended by GV is GM 12346190 or Mopar 4874459 or Castrol Syntorque. All about $20/qt. synthetic gear oils, luckily it only takes about 1 qt.
I saw an Amsoil product that works too, can't find that part#.

 

So did you ever get your Gear Vendors OD/UD unit working.

 

I hooked up the shift solenoid up to a toggle switch and bypassed the computer and she works like a charm! I ordered a dash control switch and owners manual, but have had no time to install that stuff, so I just toggle if I need OD. It really lowers the rpms, nice for the highway!

 

I was thinking of bypassing all of that gearvendor idiot proof computer junk too and just toggle it... I guess you're just supposed to use it above 20 mph or so? Also not use it with an E brake? ( I don't have one)

 

You have to be careful not to engage it or forget to disengage before using reverse, or 4wd...you don't want different final drive ratios engaging on each axle...bad noises and shearing steel may bum you and the diff's out! That's why they have the computer. I'm the only one that drives my rig, so I'm OK with it.

 

How much percent does it cut it down by? you have any idea? like is it a 20% overdrive or what....

So it shifts 1-2-3 gear and then you lock it in on the highway or is it always engaged even when going from a dead stop.

 

Yeah OBV no 4x4 with GV engaged.

The rig is going to be an idiosyncratic beast no matter what. If someone wanted to drive it, they'd have to not use the GV. The other thing is that I'll also have a Brownie aux trans behind the GV for triple OD. Would have to make sure that both of those are in 1:1 if I wanted to go 4x4. But who needs to go over 35 in 4x4? That speed is perfect for 4:10s and 4th on the getrag. 1:1:1:1:[4:10]

 

I am looking for the Gear Vendor Tailhouse section to fit a 1990 727 diesel trans.
I have the 18" section that fits a 1990 Dodge 727 gas van.
Bruce

 

Does someone have the wiring diagram again? The one in this thread is gone

I have the same setup in my truck as FlashGordon has but all the wires are cut that go into the VSS.
I need O/D. My speedo bounce around or doesn't work at all most of the time.

-Shiny

 

Hello... hello... anybody...

-Shiny

 

Tumbleweeds.... crickets....

-Shiny

 

This is right out of the manual, not sure if you can make it out.

 

i called Gear Vendors, told them what I had, and 3 days later had an install/diagnosis manual in the mail. great company! just call them!