Is My TorqShift a 5 Speed or 6 Speed?
 

Hey Guys,

I've recently been driving my 2005 F350 5.4L 4.10 w/ automatic transmission to determine my highway MPG (baseline) before installing a few aftermarket goodies. My truck is 100% stock and only has 26K miles on the clock. On Christmas Eve, I drove 263 miles to drop off a few gifts to friends and determined that I'm getting 11.82 highway MPG. Now, while driving the truck up the mountain to my ex-girlfriends house, I notice that the transmission was constantly shifting from what I thought was 5th gear to 4th gear. On really steep grades, it shifted to what I thought was 3rd gear. Note that my speed at this point was only 60 MPH. I decided to "verify" the gear and manually dropped the transmission lever to 3rd expecting no change in RPM's. Was I surprised! The tach jumped to 4,600 RPM's which means that the transmission was actually in 4th gear... hum. I was confused at this point. How could the transmission downshift two times and still be in 4th gear? The roads were wet and foggy so I couldn't pay too much attention to the RPM's while driving...

So today, I take another road trip to check both the highway MPG and the function of the transmission on more level ground. I drive 145 miles and get 12.36 highway MPG. At 70 MPH, the transmission has the following RPM's at select gears:

4th Gear: 3,100 RPM's
5th Gear: 2,400 RPM's
6th Gear: 2,100 RPM's

When I'm in what I'm calling 6th gear, I can let off the gas pedal and the transmission will shift from 2,100 RPM's to 2,400 RPM's and if I press the gas pedal again it will continue to accelerate from the 2,400 RPM point. Once the desired speed (70 MPH) is achieved, the transmission will shift back to the 2,100 RPM point. As noted above, if I press the gas pedal hard enough, it will go into 4th gear turning 3,100 RPM's. I did not "verify" 3rd gear like before because I was sure that the engine would be over 5,000 RPM's at 70 MPH. I didn't want to potentially damage either the engine or transmission.

My questions are:

1. Does the TorqShift transmission actually have 6 gears or does it have some sort of hybrid 5th gear?

2. Could the transmission be the cause of my less than desirable 12 highway MPG?

Around town, I can drive at 45 MPH and the transmission is only turning 1,300 RPM's. Is this consistent with your trucks?

Thanks for your help...

OK, the 5R110W transmission is actually a 6 speed transmission, but it only uses 5 gears at a time. There is actually 1 gear (4th I think) that is only used in extremely cold weather.

Your mileage drop is probably due to winter fuel.

Here's a better explanation, from Ford 5R110W Torqshift

The “TorqShift” (5R110W) is a 5 speed, rear wheel drive unit that actually has six forward speeds available, depending on hot or cold mode operation. The gear ratio for 1st gear was lowered from 2.71 to 3.09. For 2nd gear the overdrive clutch is applied to provide a ratio of 2.20. 3rd gear provides a ratio of 1.54, which is the same ratio as the previous second gear. All sound familiar? When in cold mode operation, below _15°C (5°F), determined by the TFT sensor, the overdrive clutch is engaged in 3rd gear to provide a ratio of 1.09 for 4th gear, and the transmission will shift directly into 6th gear (overdrive), which is a ratio of 0.71. In cold mode the transmission shifts 1st gear, 2nd gear, 3rd gear, 4th gear, 6th gear. When in hot mode the transmission will shift 1st gear, 2nd gear, 3rd gear, 5th gear (ratio 1.00), 6th gear. Either way it is still a five speed unit with six forward gear ratios available, depending on cold mode or hot mode of operation.

What can I expect when I press the "Tow/Haul" button? I read the owner's manual and it states that engine braking and slower transmission shifts can be expected. My 1997 F250 has a similar "Tow/Haul" button. When I press it, it automatically shifts from 4th gear to 3rd gear and stays there until a turn the "Tow/Haul" button off.

EDIT: The above link provides more details... thanks!

The 6 "gears" you are experience is likely the normal 1-5 shifts + torque converter lockup

I understand the concept of "hot" or "cold" mode but I'm still operating with 6 gears... I think that my TFT sensor needs to be replaced.

Your 1997 F-250 didn't have Tow/Haul mode, it had an Overdrive switch. When you pressed it, you locked out the overdrive gear.

When you activate Tow/Haul mode, you will see higher shift points. Also, when braking the transmission will shift down to assist in deceleration. It doesn't lock out the top gear, like the old transmission used to. Your top gear will still be available when towing.

Last year the wife and I were driving in Indiana, down US-41 just south of Terra Haute. We were towing around 7000 pounds, doing around 60 MPH. A stoplight surprised me, suddenly turning yellow then red. I stomped the brakes and cringed. The ABS activated, the TCS modulated the trailer brakes and the transmission shifted down very aggressively...BAM BAM BAM BAM. I ended up stopping about 20 feet short of the intersection. My wife just looked at me and said , "WOW! How did you do that?" :-hair

I engaged the Tow/Haul button several times on my 2005 F350 and there was no change in the transmission. I don't think that it is working either...

If the light comes on, it's working. Without a load, the changes may be subtle. The shifting is controlled by a computer. None of the changes are mechanically controlled. During light throttle operations with no load you could very well see no change as that part of the "shift map" would remain pretty much the same.

Try a full throttle acceleration to 60MPH with and without T/H activated, paying attention to the speeds at each shift. You should see a difference.

Like Lead Head said, you're feeling 5 gears plus the torque converter locking and unlocking. Your initial "downshift" when your RPM's went from 2100 to 2400 is not a downshift, it's simply the torque converter unlocking. By what you've described, there's nothing wrong with your truck, sounds perfectly normal.

I'll try it tomorrow and let you know what I discover. Thanks!

I hope that you are right. My truck is out of warranty so I'd like to avoid a trip to the mechanic, if possible. Thanks!

I agree. It sounds like your 5R110w is functioning just like it was designed to function.

So I'm driving to the dentist office this morning and just for the heck of it I engage my Tow/Haul button... the transmission immediately downshifts! I dis-engage the TH button and the transmission upshifts. I try it several times with the same results. This afternoon on the way home, I try it again... same results. I'm here in the Charlotte, NC area which is primarily flat land and the truck was empty.

Why didn't I get this response when I was on the mountains several weeks ago? Do you think that my TH button is failing to engage? How expensive and difficult is to replace the TH button?

A good tuner can help to straighten out some of those issues. The TQ on stock vehicles can take forever until it locks and shifting is sluggish.