Option for manually selection 3rd on 5R55E auto?

[Cstoliker]

Is there a way to add the ability of manually selecting 3rd gear in a 5sp auto 5R55E?
The truck (2000 xlt) has options for 1st, 2nd & D with a button to turn off Od (5th gear) but no way to select 3rd wich would be handy pulling a heavy trailer at 35-40mph up or down a grade.

 

[JK080]

The 5R55E achieves the five gears by turning the overdrive section on for the 1-2 shift. so 2nd gear is really just a overdriven 1st gear, and 3rd gear is really 2nd and 4th is really 3rd..., confused yet? The 4r55e and the 5r55e is basically the same tranny just the computer controls them a little different.

Selecting Drive (4th) will be the strongest way to pull a trailer for this tranny because it will be using the direct drum with clutches instead of a band. The bands in this tranny are used in 2nd, 3rd and 5th. Since the ratios are so close between 2nd and 3rd you could just use 2nd for inclines. I am not sure that it is possible to keep it in 3rd gear manually, I have never had a need to attempt it since I don't own one.

Here is the gear ratios for the 4 speed and 5 speed units to give you a idea of what I am referring too.

 

[gsbarry]

Manual 2 is actually 3rd

From the ATSG manual for the 5R:

"2nd Position
Selection of the 2 position provides a 3rd gear hold position from a manual upshift or downshift. When the 2 position is selected from a stop, the transmission will start in 3rd gear. This allows for maximum traction on slippery surfaces. Engine braking is provided In the 2 position when the Transmission Control Switch (TCS) is on or off."

This is b/c of the "virtual 2nd" as described above.