OD Idea?

[phillips5]

I was thinking:--) sence the od on our trucks is like an auxzilery. Why couldn't we shift it in and out of every gear. It would be a 6 speed auto if there was no overlap in ratios. Wouldn't that be better for pulling the heavy loads. Be like the old farm trucks with the 2 speed drive axle. It would have to be brainless od part of the valve body.

 

[Flexiheep]

Thought about it

I had the same thought, man it would be cool, and it would make people really wonder

But from what I got out of the blue Bible on the shelf is that the valvebody doesn't port fluid to the OD circuit till you are in 3rd gear, then the OD solenoid will allow 4 gear shift. I could be wrong, but the way I read it means you would have to do valvebody work to get fluid where it needs to be. Plus I am not sure that the OD assembly could take the torque multiplication in first and second gear, especially while towing when it would be the most benificial.

Someone chime in if I am wrong though.

 

[RGT]

I have a manual bypass switch to engage my overdrive and a couple of times I have driven around with it engaged all the time, makes the truck a little sluggish off the line... ...

 

[cerberusiam]

Like RGT said leaving the selector in drive and using a mystery switch the OD stays engaged all the time but when you manually shift the gears I believe OD is locked out in the VB.



That would definitely help on the 1-2 shift since first is fairly low. Have to run the numbers but off the top of my head that may put the 2nd gear OD real close 3 direct.



If you shift each gear into OD well out of the TQ curve it would probably live as the line pressures would be high enough but that would defeat the pupose of keeping the egine in the TQ band on acceleration. If you tried to shift into OD at TQ peak I don't the parts are big enough to take the abuse and live very long even with the lower effective gearing. You could make the pressures high enough to apply and hold but the amount of power being transfered would put a strain on the OD section. I am pretty sure the VB could be modified to allow OD on a manual shift but whether you could get it to auto shift in and out as the gears change is beyond my comprehension at this point.



That is just a great idea and one of things I just love about this place and the people in it. Even with the drawbacks, in certain cases that would a really cool modification. My trans is not long for this world and this is just a cool enough idea I may try it and see how much it hastens the end.