Question for the Mad Dr.
 

Or for the Mad Dr. Jr. (that would be you Jack and Janet)... You know how our trucks reduce power when you manually shift to 2nd or 1st? Can that be programmed to go away with a custom tune? It's really annoying. Is there any other way to override this feature?

I don't understand what you're asking here. Are you talking about the "lurch" down that you feel when you downshift using the lever, but haven't increased the gas yet? I know, with a manual, it's easy to feed in the gas full as you let out on the clutch after a downshift so that the power is immediate, but it's not so easy to time it right with an automatic. I can't imagine there'd be any way to eliminate the lurch, but, maybe I'm wrong.

I think though, you could force a 3-2 downshift by stepping on the gas and then, once it's in the new gear, just drop the shifter into 2nd to keep it there. That would avoid any loss of power.

And, you could do the same thing from 2-1.

Oh, and thanks for the "Jr" title. It feels like an honor (totally undeserved).

- Jack

I think hes talking about when you put it in 2nd or 1st from a dead stop it is not as responsive compared to D.

If you put it in 2nd gear, it stays in 2nd gear...all the time. That includes when you start from a dead stop.

I know. I think he was wondering if you could customize one gear.

When it is put into any other gear than d, an electric bypass of the fluid in the transmission happens. It rather an extensive technical issue the way the tranny is set up like this. My understanding is that it allows for more continuous power with out allowing the torque convertor to lock up at all. It operates like an old power glide at this point.

They probably did this so if you are probably stuck. Its easier on the tranny and power train. I really don't think they engineered it to be used this way on hard surfaced roads.

When in 2nd mine does shift up from 1st.

Lars

It's useful in an uphill climb where the power requirements keep causing a shift in and out of 3rd to 2nd. Better just to stay in 2nd. I would not have thought though, that the converter would not lock if the power demand stabilized. I'll have to test this. If it doesn't lock, why do we have lock/unlock adjustments for 1st and 2nd gears?

I think you're right about shifting up from 1st into 2nd though if the stick is put in the 2nd gear position. But again, I need to try this to see for sure. If so, it's too bad, since it keeps you from using the old start in 2nd trick to keep from losing traction on very slippery surfaces.

- Jack

One of the reasons the tranny does this is at normal d driving you are getting enough air to keep everything cool.

The lock up feature on the tc locks fluid in in there at normal driving. Now if it locks fluid in there you have less fluid to use to cool the system. Now if towing really heavy loads its recommend to turn off the od and essentially that turns the lock up off. Thus allowing for more fluid to cool.

The lock up feature is also used when in d for the other gears also kind of acts like a half gear sometimes.
So by putting into 2nd you are telling it to shut off the lock up and not going to be driving in normal conditions. I do not know if the gryphon can be tuned to change this.

Yes Jack I to use the gears to get out of slippery situations too.

Lars

That is an incorrect statement.

Towing with the OD off allows the tranny TO lock up the TC so that it does in fact run cooler. Towing with the OD on, (in most cases), will have the truck running in 4th gear with the TC unlocked and causing a large amount of unwanted heat.

Yes I was wrong!

Turning off the od will eliminate the back and forth shifts from 4th to 3rd, 3rd to 4th, but not the lock up.

Once again I apologize "put the cart before the horse"

Thanx for the correction.

Lars