Macrobb
Full Access Member
So, I just figured I'd throw in with some info about running a GV in 'manual' mode.
First off, there are a few dont's that the controller protects you from:
1. Overdrive in reverse. If you do this(mainly by leaving it engaged when stopping), the truck will move in reverse with more effort, like you put the brake on.
It will also make bad noises. Don't do this, because you are wearing out the clutch.
2. Overdrive in 4x4. For it to be a problem, you must be in 4x4 on the transfer case, with the hubs locked in(i.e. actually in 4x4). If you manage to engage Overdrive, the truck will shudder violently, and I'm sure you are putting major wear on that clutch.
3. Running at too low speed. Now, this is a mixed bag, and I suspect the 'real' reason for the lockout has to do with how much torque you could put through the GV flooring it in 1st.
I've found that the GV will stay in Overdrive if you roll to a stop with it still engaged, and will stay engaged at least long enough to take off again, wondering why it's feeling sluggish in 2nd(because you are starting in 2nd-over).
If you have it disengaged, turn the switch on, and start moving, it will lock up at some random time, usually by 10-12MPH. It has to build pressure internally, after all.
Also:
You will find plenty of people saying to disengage your GV/not be in double-overdrive when towing.
Still not sure /why/, considering the torque through the GV is relatively low at that point. I'm guessing it has to be to prevent overloading the engine.
Of course, once you put a big turbo and pump on your engine and end up with /lots/ of torque and HP, it's totally doable with a light trailer, especially when hauling at 70MPH. I've done this many times...
I want to point out that /none/ of this is hearsay. I have done each and every one of these things, and(surprisingly enough), my GV hasn't exploded yet.
Also, as another tip, it's recommended that you change your GV fluid every 30K. They specify some odd GM fluid, but I used Royal Purple Synchromax, IIRC. At the time, they were recommending ATF, but have since changed to recommend a special GM gear oil.
So far(last 5 years) I haven't killed it...
First off, there are a few dont's that the controller protects you from:
1. Overdrive in reverse. If you do this(mainly by leaving it engaged when stopping), the truck will move in reverse with more effort, like you put the brake on.
It will also make bad noises. Don't do this, because you are wearing out the clutch.
2. Overdrive in 4x4. For it to be a problem, you must be in 4x4 on the transfer case, with the hubs locked in(i.e. actually in 4x4). If you manage to engage Overdrive, the truck will shudder violently, and I'm sure you are putting major wear on that clutch.
3. Running at too low speed. Now, this is a mixed bag, and I suspect the 'real' reason for the lockout has to do with how much torque you could put through the GV flooring it in 1st.
I've found that the GV will stay in Overdrive if you roll to a stop with it still engaged, and will stay engaged at least long enough to take off again, wondering why it's feeling sluggish in 2nd(because you are starting in 2nd-over).
If you have it disengaged, turn the switch on, and start moving, it will lock up at some random time, usually by 10-12MPH. It has to build pressure internally, after all.
Also:
You will find plenty of people saying to disengage your GV/not be in double-overdrive when towing.
Still not sure /why/, considering the torque through the GV is relatively low at that point. I'm guessing it has to be to prevent overloading the engine.
Of course, once you put a big turbo and pump on your engine and end up with /lots/ of torque and HP, it's totally doable with a light trailer, especially when hauling at 70MPH. I've done this many times...
I want to point out that /none/ of this is hearsay. I have done each and every one of these things, and(surprisingly enough), my GV hasn't exploded yet.
Also, as another tip, it's recommended that you change your GV fluid every 30K. They specify some odd GM fluid, but I used Royal Purple Synchromax, IIRC. At the time, they were recommending ATF, but have since changed to recommend a special GM gear oil.
So far(last 5 years) I haven't killed it...
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