How to disable OD on the 4+3 manual tranny

[MacVette86]

Thanks for all the great advice folks. I spent today completely removing the interior and carpeting from the car and I found the OD problem. The switch on top of the shifer wasn't connected to anything. No wires, no threaded rod, etc. So I really need a way to mount tis switch on the console. Good news is the dealer I bought it from is going to do this for me. I will watch closely and take notes

 

[rrubel]

Thanks for all the great advice folks. I spent today completely removing the interior and carpeting from the car and I found the OD problem. The switch on top of the shifer wasn't connected to anything. No wires, no threaded rod, etc. So I really need a way to mount tis switch on the console. Good news is the dealer I bought it from is going to do this for me. I will watch closely and take notes

Find a driver's info center cover from an 84 or 85 - they have a spot for the O/D switch. Then you can re-route the wires there.
[RICHR]

 

[MacVette86]

I found the problem. I took the interior out to start the restoration and had to remove the shifter knob. Well, there was no threaded rod in my shft handle and the OD button isn't hooked up to anyhting! I found a couple of loose wires under the console which I assume were used at some point to control the OD relay. The dealer I bought it from is going to fix it and out the switch on the console.

 

[WhalePirot]

Black and dark green wires feed my O/D switch. It is screwed to a lower piece, just in front of the center glove box, which the center trim piece just covers.

The dealer may find it easier to install the '86 parts, rather than try to convert it.

 

[MacVette86]

Problem is now officially solved. I now have a toggle switch on my console just behind the shifter. Sitting back with my arm on the console, the button is righ there anytime I need it. Works great too! Cruising along in OD, all I have to do is hit the button and I down shift into fourth. Then hit the bitton again and back into OD I go. Also, no OD until I hit the button no matter waht temp, gear, etc. As far as I can tell, this is how it should have been from the factory.

 

[rrubel]

Remember, the 4+3 and its quirks were specifically created to save gas while still offering performance. GM, in order to boost its CAFE rating, wanted the default to be "economy."
[RICHR]

 

[MacVette86]

I was surprised at the gas mileage I'm getting. On the highway at a constant 70 MPH, I get 24 MPG! Not bad for a sports car.

 

[nyernga]

I was surprised at the gas mileage I'm getting. On the highway at a constant 70 MPH, I get 24 MPG! Not bad for a sports car.

And to think.......intitally, you didn't even WANT the OD......

Congrats on the fix..........now go enjoy it...

Len

 

[rrubel]

I was surprised at the gas mileage I'm getting. On the highway at a constant 70 MPH, I get 24 MPG! Not bad for a sports car.

That's with OD, right? Without it, you'd be getting more like 15-16 in 4th. That is a TALL overdrive gear.
[RICHR]

 

[MacVette86]

Yes that is with OD. I'm used to getting about 13-14 MPG on average in my truck, so this is great!

 

[WhalePirot]

Y I'm used to getting about 13-14 MPG on average in my truck

You can always modify the engine and get back to those figures....or worse!

I wonder if Ken, with similar engine, gets lousy mileage, as I do. The good news? I can get to a gas station REAL fast!

 

[rrubel]

I wonder if Ken, with similar engine, gets lousy mileage, as I do. The good news? I can get to a gas station REAL fast!

And at today's prices, you can empty your wallet equally fast :cry .
[RICHR]

 

[hAZcAT]

the 4+3 trans is really a cool idea, I really like mine.