If you have a 4 bolt cover you have a Borg-Warner overdrive transmission, a non-synchro 1st gear, 2nd and 3rd are synchro, the same model I have used on my daily driver for the last eight years. Please consider this advice for years of enjoyment…
Precautions:
1. It is inadvisable to down shift to 1st gear while the truck is moving. Actually you can, at like a crawl, but not down shift to slow the truck down as you don't have 1st synchro to smoothly engage the transmission.
2. To start out in 1st gear from a dead stop, shift the gear box into 2nd or 3rd using it’s synchro to stop the transmission so you can shift into 1st without grinding. Try it both ways; you'll soon see what I mean.
3. Never or seldom if ever start the truck in 1st gear overdrive. I have had my transmission apart a few times replacing bearings and such and the overdrive mechanism are too fragile to use on a regular basis for starting the truck from a dead stop. How am I sure of this? The dearly departed past president of Inliners, Jack Halton, sold me this transmission and told me not to start out in 1st overdrive (that means any overdrive gear).
4. When reversing the truck you must disengage the freewheeling, by pulling your lever out, thereby putting the truck in DIRECT DRIVE. What is direct drive? Your transmission is like having two transmissions, if you have the LEVER OUT (your pull cable), you should be in direct drive and the transmission acts like any other trans., the gearing slows the vehicle down, same 1st gear rules apply above, you can not engage overdrive while in direct drive. LEVER IN, the vehicle is in freewheeling mode, the ability to engage overdrive; you use your brakes rather than the transmission to slow the vehicle.
How to drive:
This is the easy part. You are in freewheeling mode (overdrive control pushed IN), overdrive capable. Start the truck in neutral. Clutch in, shift to third then to first, engage clutch, advancing speed, shift to second, more speed needed? Hit your Overdrive switch ( I don't have the governor and any kick-down switches involved with my transmission, I use a simple ON/OFF switch with a reminder light included to turn my overdrive function on and off), let up on the gas, you are now in 2nd Overdrive, more speed? Shift to 3rd and you'll be in 3rd overdrive. Need to slow to stop? The Overdrive will aid you by helping to slow down with the transmission, but don't overdo it, the old axiom applies... What are cheaper, new brakes or a new transmission?
This assumes you know how to drive a standard shift. If you don't know how as yet, I wouldn't learn with this transmission. The hardest rule is #4 above; the overdrive is used for forward movement only, enabled when you switch the solenoid. The solenoid is a device that performs a sustained push to find engagement of the overdrive. Since the overdrive system is all forward motion gears you will harm the overdrive by trying to reverse while engaged in overdrive. When you need to back the truck, you need DIRECT DRIVE (Pull your overdrive cable OUT), to use your reverse gear, again #4 above.
The solenoids job (beer can size cylinder on driver’s side of trans.) is to engage the overdrive, but you must let up on the gas for it to do its job. An addition that I have found is very helpful is to wire in an 'idiot light' into the overdrive circuit switch (when the OD is ON the light is ON) in a location where you'll see it. Having that RED LIGHT (or any color you choose) in plain view is a good reminder to NOT start out in OD, and NOT to try to shift into reverse in OD freewheeling.
Disclaimer: I will not accept any responsibility for the damage you may incur by the directions above. I suggest confirming this advice with others for it's accuracy before accepting it as the truth.
POST SCRIPT: By setting up this transmission with an on/off switch I can actually split the gears to get 6 forward gears, 1st, 1st od, 2nd, 2nd od, 3rd, 3rd od
