Found a GearVendors OD. How to install?

[rockspider]

I was looking for a 4L80 swap in my diesel CUCV (TH400-NP205) and was really sad to see what crazy prices those trannies have here in Europe, when all of a sudden found a GearVendors overdrive for a mere $500 out of a 2wd wrecked Ford. This OD has always been my other option, so I took it immediately. The seller assured me that the unit was working fine before the road accident, and it shows no sign of wear or damage.

Problem n°1, the unit has a Ford C6 adapter, and GearVendors asks $900 for the NP205 adapter & sleeve I need. No way I'll pay that much. So I'll have to make my custom adapter. It doesn't seem that difficult, providing some lathe work, and it should end up being shorter than the GV adapter. I think my adapter will end up less than 2" thick. The plan is to "shave" a NP205 output yoke and use the resulting splined tube as the actual coupler sleeve, shortening the output shaft of the 205.

Problem N°2, the real one. I have no control module, and after the adapter I am scared to ask GV the price of a controller alone!!
Can I just switch it on/off as needeed? There seems to be just a big solenoid with two prongs, can I just ground one and switch the other +12volts, or does it require something different?
Is there anything else I am missing before /forums/images/graemlins/hack.gif

Thanks for any suggestions! /forums/images/graemlins/thinking.gif
Alessandro

 

[m j]

I cannot imagine the electrics being too complex as it is only a 2 speed.
either on or off if you do not want it to automatically split gears for you
GV is on bad drugs quoting you a price that high
I am very confident you can build those parts for way under $900
what are the input shaft details on the GV unit? spline count? male/female?

 

[rockspider]

The GV OverDrive unit has a short (about 1") male spline input shaft, which is the same 32 splines found on the NP205 output. So I plan on using the splined section of a 205 output yoke as a coupler between the two male 32 splines shafts (shortening the 205 output accordingly). The adapter needs a bit more R/D than expected, as looks like two levers on the coupling side of the GV needs some space to move toward the transfer case as it shifts into OD, still unsure how much space they'll need though.
I'm also thinking to unbolt the solenoid-valve from the case and electrically test it alone to (hopefully) discover how to correctly power it on and off.
Is there anybody that has opened or toyed in some way with one of these units?

 

[FWP]

[ QUOTE ]
Can I just switch it on/off as needeed? There seems to be just a big solenoid with two prongs, can I just ground one and switch the other +12volts,

[/ QUOTE ]

Yes, you bet. All the "controller" does is shift based on feedback from the speedo unit (installed seperately on the speedo cable), and limits the OD from engaging under about 15MPH. You shouldn't start out from a stop in 1st over, not good for the tranny...

Hope that makes sense.

 

[rockspider]

Uhm, yes... I think you're right... it makes sense, indeed, as from what I see it works from pressure developed from the front pump, and 'till you don't move fast enough it won't develop enough pressure for shifting or to keep it shifted to over anyway...
I would imagine that trying to start in Over would just spin and burn the OD clutches 'till enough pressure is developed, then it suddenly engages. (bad thing... /forums/images/graemlins/shame.gif )
I'm thinking of wiring the solenoid in such a way I can manually shift it (that does require brain inputs indeed, that I hope to be able to perform... /forums/images/graemlins/woot.gif ) and also a second solenoid will automatically disengage the OD each time I hit the brakes (through the hot wire for stoplights) to be sure I don't forget to disengage it at very low speeds or from a dead stop. A bright led on the dash for OD engaged would help too remembering its status.
What do you think?

Oh, very important question, anybody knows how much fluid does it requires? Looks there's no level to check! How do I know the level? Does it accept regular Dextron II ??

 

[FWP]

I wouldn't put in an extra switch off the brake. Having the OD shift off every time you hit the brakes would be annoying IMO.

The light idea is excellent. The manual/ auto switch that came with mine uses a green light when on and a red one when off, or no lights when in Manual off.

Yes, Dexron 3, tranny fluid, fill up to the fill plug. I'm not sure of the capacity. It might be a good idea to get ahold of Gear Vendors and see if they would send you a manual. It's pretty detailed.