Using the doug Nash 4+3 o/d without a computer
Thread Starter
Heel & Toe
Joined: Aug 2003
Posts: 15
Likes: 0
From: omaha NE
Using the doug Nash 4+3 o/d without a computer
Is their a way to use the 4speed and o/d unit in, say my 66 Impala.Is anyone familair with
its workings that some kind of switch or something.You tell me.
Thanks
Frank
its workings that some kind of switch or something.You tell me.
Thanks
Frank
Race Director
Joined: Oct 2000
Posts: 16,477
Likes: 1
From: Enter Post Count Here
Re: Using the doug Nash 4+3 o/d without a computer (vettework)
I'm sure there is, although it wouldn't be an automatic OD anymore, it'd be manual. I don't have my schematics with me where I am, but I'm sure it's just a go/no go signal that locks the OD clutches. I'm sure someone will chime in with schematics.
:seeya
P.S. Unless you've got a free 4+3, I'd go with a different trans. :seeya
:seeya
P.S. Unless you've got a free 4+3, I'd go with a different trans. :seeya
Drifting
Joined: Mar 1999
Posts: 1,931
Likes: 1
From: Norcross GA
Re: Using the doug Nash 4+3 o/d without a computer (NoWorries)
The OD On/Off operates off of +12v or not. The circuits controls (relay) changed over the years, but it is still the same +12v or not. You could control it w/ a relay or a switch. But, like said,... it will be manual.
Thread Starter
Heel & Toe
Joined: Aug 2003
Posts: 15
Likes: 0
From: omaha NE
Re: Using the doug Nash 4+3 o/d without a computer (NoWorries)
I had the makings of a 71 lt-1 350 aka a 010 hi nickle/ tin block, forged crank and 487 heads from a low mile 71 3/4 ton p/u for about 10 years, I gave it to my brother for his father/son 66 impala ,Last time I went over the car had no front on it and everything was rusted,So they gave me the car, and I got a free transmission from the guy next door,Is all rebuilt except the heads and the back part of the trans........so its ether get a t-10 tailshaft and housing or go for the overdrive.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: Using the doug Nash 4+3 o/d without a computer (vettework)
Sure it can be done! All the ECM does is fire 12v out a certain pin to the O/D relay when there is an "O/D Request". This 12v goes to the relay which then enables to O/D solenoid inside the overdrive unit. When this happens as long as there is sufficient fluid pressure in the tranny the pressure switch holds the ground contact and O/D enables. If fluid pressure dropped below acceptable values (like when rolling to a stop) the pressure switch opens the ground and O/D would disengage on you.
