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Discussion Starter #1
Looking around the net at all things 6.0L PSD I cam across a Wikipedia page about the '99-'11 Superdutys and it had some interesting info in it. I'm sure you guys know this but just in case here's what it said about the 03-07 TorqShift:

"The TorqShift design in fact has six forward ratios, but only five are advertised, with the 'hidden' gear only used in extreme cold weather. The TorqShift 1st to 5th gear ratios are 3.11, 2.22, 1.55, 1.00, and 0.71:1. It also utilizes an alternate 4th gear, overdrive on 2nd gear of the 3 speed automatic component (0.72 x 1.55), that is 1.10:1 that is used under cold start conditions to aid engine and transmission warm up."

I'm confused. Can someone explain that? I'm assuming it's like a "in between" type of gear that makes the engine stay reved up as you drive???

LINK: Ford Super Duty - Wikipedia, the free encyclopedia
 

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The normal shift pattern is 1-2-3-5-6. 4th is engaged if the fluid temp is 0* or below. The shift pattern is then 1-2-3-4 until the fluid temp exceeds 0*. There are also some downshift situations where 4th is used.
 

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Discussion Starter #4
That's pretty wild! So the idea is to keep the engine reved up to help the eng/trans warm up faster? When you say 0* you mean ambient tempature, right?

I guess I may never experiance this because my truck will be stored for the winter. No salt for my baby!.
 

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Former Ford Trans Engr.
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That's pretty wild! So the idea is to keep the engine reved up to help the eng/trans warm up faster?
No, that's not the idea at all. I was part of the decision to do this as I worked on the TorqShift calibration from 2001-2004.

It shifts 1-2-3-4-6 when the trans temp is less than 0°F because we couldn't make the 3-5 shift work correctly at those cold temperatures. Once it was warmer than 0°F the 3-5 would work again.

It isn't well known, but sometimes the trans uses 4th gear instead of 5th gear even when warmed up. If the truck is going too fast to go to 3rd gear when the go pedal is floored while in 6th gear, but slow enough that there won't be a lot of acceleration in 5th, the trans will go to 4th gear. That will give 10% (1.10:1 vs. 1:1 ratios) more acceleration. From 4th gear the trans can shift to 6th or 3rd, but NEVER from 4th to 5th.
 

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The Unseen Mod
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Ah glad to have you back Mark haven't seen you on in a while
 

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Former Ford Trans Engr.
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Ah glad to have you back Mark haven't seen you on in a while
I check here almost every day, but if there isn't something that I have a comment to make you don't know it.

A bit more info:

The reason there are six gears is that the trans is a three speed with a two speed in front of it. It really is two transmissions in one case. Here's how each ratio is created.

Front trans / Rear trans /Overall ratio
First 1:1 /3.09:1 / 3.09:1
Second 0.71:1 /3.09:1 /2.24:1
Third 1:1 /1.54:1 /1.54:1
Fourth 0.71:1 /1.54:1 / 1.1:1
Fifth 1:1 /1:1 / 1:1
Sixth 0.71:1 /1:1 / 0.71:1
 
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