The OD switch locks out Overdrive not torque converter lock-up. These are different things. Your torque converter will still lock in 3rd gear if you lock out OD. Try it some time.
Tap the brake pedal while keeping a constant speed. You will see the RPM flare for a second as the TQ unlocks then re-locks.

 

You aren't supposed to have a ton of power in OD. It's more of just a gear to go into once your up to speed. I think that part might be normal. Mine doesn't have a ton of power in OD but if I get on the gas more than probable half throttle it just kicks down a gear into where it has power. Not a big deal. It doesn't just drop off in power in OD but it doesn't have a ton either.

I think your rough shifts might be a wild shift kit or they removed that check ball I told you about maybe. I don't really know. Mine shifts firm and it's a little hard in 1st to 2nd if I'm not on it more than probably half throttle but it's not bad and the other gears it's not too hard either. This is with a Transgo Shift kit installed in the APS transmission. Of course the rest of the transmission is built too.

I really don't know why yours is like that. My transmission is pretty darn heavy duty with quite a bit of stuff done to it and it's not a chore at all to drive. Infact I love it. It's not at all bad like you describe. It shifts better than the OEM one. Faster and firmer and just all around better without being a chore to drive.

 

I'm not sure if what my truck did is the same as yours, but it sounds very similar. It would shift into OD way too soon causing a major drop in rpms and torque, and then I had to push down quite a bit on the accelerator to get it to come back out of OD so it would get up and go faster. I adjusted the cable and it improved things a lot. It won't shift into OD until I've hit 45mph now, but if I push it a little more, it will drop back out of OD much sooner than it did before, giving me much better throttle response when accelerating from 50mph or more.

IF you decide to adjust yours, do a search read up on exaclty what to do with it. They mean what they say when they talking about moving it 1/8th inch at a time. It is very easy to move it more, but if too much, I think the line pressure in the tranny may exceed safe limits and could cause damage. Start by taking note as to where your cable sits before adjusting it. This way if you move it too much, you can very easily put it back to where you started with no worries. Then, I would try moving yours back towards the cab by 1/8th inch and gently drive it for a miles so the PCM, and YOU can get used to the new setting. If it isn't performing as you like, you can then adjust it another 1/8th inch until you find the sweet spot. DO NOT get too carried away with these adjustments and testing. If you have adjusted too much at once and get crazy with it, you could cause some type of damage, based on the research I did before I adjusted mine. A very small adjustment on this cable makes a huge difference in shifting! As long as you take a careful approach to these adjustments, you should be just fine. As long as you know where the cable was before you started, you can always put it back to where you started. I took a digital picture of mine before I adjusted it so it was very easy to see what the original position was. Knowledge with PACIENCE is the key to success.

 

So your saying your truck drops into overdrive around 45mph? That's what mine does as well. Is it normal that the truck does a nasty shift going into overdrive as well? It's hardly ever smooth especially if I have the throttle down medium way. I mean, this could be normal. But it's not to me, I never had this problem with the other transmission, it just always had power, there was never a certain speed where it would loose power and throttle response. But I can tell now when it does. Once I get passed 45mph, the truck falls into overdrive, and the engine just sort of makes this straining fluttering sound from the engine. Once I get speed going, it's ok, but at first, it's a bitch just trying to sustain 50+mph speeds.

I was going up a diesent sized hill last night and the transmission was in the overdrive gear, and the truck barely had enough power to get up the hill. The rpms started doing the jumping thing like it used to with the old transmission.

Went I brought my truck to Aamco Transmission, the guy told me that "it was too much of a good thing". He siad the transmission was stronger than the truck. He told me that if I ever keep building it up, it will handle it better. I wasn't really sure what to say. I had this other transmission shop complimenting New England Transmissions transmission, so I couldnt complain there. But, I'm the guy who drives this truck everyday, and it just gets really tiring fussing around with all the weird bullcrap. I'm fine with the HARD shift out of first gear. Second gear is great. Third gear is fine. But when it gets into that overdrive gear at 45mph, truck just feels disconnected, the muffler isn't purring anymore, the gas pedal won't let the engine explode,it's really annoying. I just want to just enjoy myself while I'm driving and not dealing with the weirdness[8D]

 

Some of that is going to be because of your gears and 35" tires. My truck acts somewhat similar (or did) because the rpms were so low when I would get into overdrive, i'd have no power at all. Couldn't hardly maintain highway speeds, escpecially if there were hills. Guess i'll see what the 4.56's are like, should be better.

 

These are my thoughts on the subject, and not from actual knowledge.

It sounds like possibly that the torque converter is locking up in low rpms and doesn't allow any slippage, therefore causing the engine to feel lifeless. Think of it as a manual transmission. If you just let out on the clutch all at once in a higher gear(like the torque converter locking in at low rpms) without allowing the engine to rev, it will bog down the engine and it will feel lifeless. Since you have gotten a heavy duty tranny, it is probably set up for low end torque from the engine, so you would want it to lockup in gear to take full advantage of the engine's low rpm torque for towing. I could be wrong, but if the cable is adjusted to allow the tranny to shift later, and kick down earlier, this may help with the OD making the truck seem lifeless. I would at least try it as I posted before; it couldn't hurt. If you don't get any good results from that, then I would just run with OD off unless I was going to drive over 50 for any length of time. I do that anyway if I am in a lot of stop-and-go traffic. It doesn't hurt anything to do this, and it drives much better. I think of the OD kill button as my "Performance Switch". I remember one of my friends from the past had a Saturn that actually had a button identified as "Performance Mode" that took it out of OD and raised the shift points of his tranny. I think the OD switch in our trucks does the same thing. (or at least something very similar)

 

That's right, you had 4.10s with 35s for awhile. Did you notice a lack of throttle response in overdrive? The rpms just kind of want to stay at 1500, there is no powerband at all. So, I guess I'll just wait to see if the 4.56s gears will fix that. I'm still puzzled though, my other transmission never had power issues no matter what speed I was going. This is all new to me this overdrive business.

 

Interesting. And it's true. When I take it out of overdrive, the truck is very powerful. When I'm in 3rd gear, the truck can easily power its way up hills, or get up to 85mph very easily. But then your dealing with the high rpms, so it's nothing you can really sustain. It's defiantly a different feeling. I don't know what was in my other transmission that made it shift so nicely and have such good power. It bugs the hell out of me though when I drive down backroads in overdrive. Every bump I hit makes my foot hit the gas pedal so it just like does quick little revvs, it's pretty annoying, but that's how much pressure I have on my foot just to keep the **** moving past 50mph. Truck is defiantly a chore to move around. I mean I love it, but still a pain in the ***. I really want some all-terrain tires too. I've had my fill with the mud tires lol.

 

Think of overdrive as riding a 10 speed bike. When you take off in first gear, it is really easy to peddle. As you go faster you switch to 2nd, then third, and so on. Now, think of riding it this way. Take off in 1st, then switch to 3rd, then to 5th, then switch to 10th. You would gain speed quickly by peddling hard and skipping 2nd and 4th, and you wouldn't be working so hard to get going fast. Then you shift to 10th to keep you cruising along without ahving to peddle like a madman. As long as you didn't have any head wind or inclines to travel, you could maintain that rate of speed without having to work too hard. BUT, trying to accelerate in 10th from the cruising speed would be VERY difficult. You would shift down from 10th (OD) to get going faster, then once you reached the speed you wanted to maintain, switch back to 10th (OD). This is kinda like how vehicles use OD. At least this is the easiest way I can describe how I understand it works. Our trucks just seem to have a wider spread between the power and the OD gearing. So, with that thought in mind, if the tranny cable is adjusted to upshift later, and downshift sooner, it would make it easier to accelerate and maintain vehicle speed, shifting into and out of OD at better suited engine speeds, thus making it seem to come alive again.

 

So are you saying that's ok to take it out of overdrive while I'm driving down the road. Lets say I'm in overdrive coasting along fine, but I see a big hill coming up. Is it bad to take it out of overdrive, or is that ok? Also, are you saying that if I'm trying to accelerate or gain speeds, I should take it out of overdrive, and then wehn I get to the speed I want, put it back into overdrive? I just wasn't sure if this could cause damage to the transmission if I was always switching it on and off all the time ya know??