Originally Posted by TheGreek!

If I'm not mistaken you only need to hit the clutch when you initailly engage the overdrive, once it's on it will stay on until it's turned off. That's why you don't have to hit the clutch to engage the overdrive in second, third, and fourth when starting off in first if the overdrive is already on.

Originally Posted by FOURSPEEDVETTE

Plain and simple of it. Operate 1st through 4th gear just like any 4 speed transmission. You may not even want to use overdrive. But if you do want to, use the overdrive only as a fifth gear. You only need to use the clutch once when you switch the overdrive on after 4th gear, and once when you want to turn the overdrive function off. No one drives a 4+3 the way described here. Unless they're an idiot. It's not a 7 speed transmission. 2nd gear overdrive feels like 3rd gear. 3rd gear overdrive feels like 4th gear. And 4th gear overdrive feels like a fifth gear. Fairly simple.

Originally Posted by Bfenty

only reason to use in any other gear than 4th is to downshift while it's on. I'd rather downshift to 3OD than turn off OD, then turn it back on. My switch is on the console though not on the stick-if it were that might change my opinion.

Originally Posted by FOURSPEEDVETTE

Being that you have a 4+3, I'm sure you understand my next statements. But for those who don't know this, true, you can downshift in overdrive all the way down to 2nd gear without turning off the overdrive. When you come to a complete stop, the overdrive disengages automatically through the use of a vehicle speed sensor. If you leave the overdrive on, it will automatically engage back into overdrive in 2nd, 3rd, and 4th gear. 1st gear does not have the overdrive capability. Thus the 4+3 designation.

Originally Posted by Bfenty

Yup. It's a confusing transmission to use. I typically just leave the OD on when I'm doing highway driving and shift up/down as needed, turn it off when I'm driving around town. I'm not sure if that's how it is supposed to be used but that's how I use it.

Originally Posted by Bfenty

Yup. It's a confusing transmission to use. I typically just leave the OD on when I'm doing highway driving and shift up/down as needed, turn it off when I'm driving around town. I'm not sure if that's how it is supposed to be used but that's how I use it.

Originally Posted by FOURSPEEDVETTE

That's exactly how it was designed to be used. GM originally designed it for fuel conservation regulations back in 84-89. Some people actually think you have to shift it 7 times going down the road. Lots of bad/wrong information has been spread from know it all's who actually know nothing.

Originally Posted by Bfenty

Cool, thanks. I feel validated now. Now I just have to get my OD FIXED...I actually have a replacement OD unit but I have to drop the transmission to install it, and that's a whole lotta work from what I hear.

Originally Posted by arbee

Haven't done one but can you not just remove the C beam and unbolt it from the T10 with the 4 speed staying where it is?

Originally Posted by Bfenty

Can you? Because that would be awesome.

Originally Posted by Bfenty

Originally Posted by ihatebarkingdogs

I don't think you can. Not enough room in the tunnel.
AND: The reverse idler gear shaft is part of the overdrive assembly. IIRC, the best way to assemble the OD to the 4-speed is vertically, so you can center the idler gear, then drop its shaft (which is attached to the overdrive) down onto it. Attempting to do it horizontally (as installed), the idler gear drops down, and the shaft won't go into it.