I did a search and could not find any opinions on this. Do you use the tow/hall botton or not? I will be towing a 7000# boat trailer with my 05 6.0 excursion. I have the diablo set on the 65hp setting. SO do I need to hit the button, what does the button do? Thank in advance.

 

Tow/haul mode changes the shift pattern and runs higher rpm to shift. It will hold the gear longer and to a higher rpm before shifting to another gear. Also if you have the TS is will down shift when you start using the brake.

 

I'd check your owners manual. I'm pretty sure it says not to use OverDrive when towing if you have the TorqueShift transmission. The design of the OverDrive components make them the week link in the drivetrain. Adding excessive load to them could result in premature failure. That's just one reason to use Tow/Haul mode. The rest is in the manual. Personally I think it's a judgement call. If you're towing a light load on a flat or even a slight incline, if the engine is not laboring, then why not run in OD? But to tow/haul more than 70% of rated capacity at increased incline then steps need to be reccognised that you could be achieving limits beyond design. Sure our trucks are rated for X. But should we push them to "X"?

Personally I tow a modest 6,500 pound 25 foot camp trailer down the road with my ZF6spd in OD. (that's fifth gear. 1st is granny gear.) As long as I can remain in the power band of the engine. Any percieved drop in rpm, then I drop a gear. But that's me thinking. Not letting a computer do it all. I can see that incline up ahead and adjust. The computer senses and is reactive to the TorqueShift's transmission needs. It's reactive. Not proactive.

Now for the tuner. Are you monitoring EGT's and Boost? That's not the only thing to regard when running performance enhancing modules. But it's a start. Adding the 65hp mode, equating to more torque available to the drivetrain, in itself is not damaging. But using that power to lanch your truck and boat up the steap boat launch because you can, isn't the most intelegent thing to do. I know people with tuners that are towing, Successfully without damage to their rigs. I know others that abuse that newfound power and drive their wife's rig while their truck sits in the shop for repairs.

 

The Drive/Overdrive are not manually selectable on the Torqueshift. When downshifting you put the truck into third gear; a two gear drop from O/D. Really shoots up the RPM's if you're at highway speed. The manual states that Overdrive is always available. You might want to downshift if you find your truck constantly searching between drive and O/D. Use the Tow/Haul; it not only adjusts the shift pattern as stated above but also provides some braking. I've notice that a few on this forum use the T/H even for daily driving.

JMHO

 

Sanpanchoseue, Since I don't have the TorqueShift, and since it may help Bhammer, Doesn't Tow/Haul mode, (along with a slew of other braking and shifting advantages), effectively take the transmission out of OverDrive? Limiting to 4th gear until braking is applied to a force that would neccessitate a drop to 3rd gear? You're saying that it can remain in OD with Tow/Haul engaged? If not, isn't that a means to manually/electronically disengage OD?

I guess I'll have to read my own manual to educate myself on the transmission I don't have.

 

The Drive/Overdrive are a single selection on the steering column just like always. With the replacement on the drive/overdrive button on the selector arm there is no longer a way to drop out of overdrive. The T/H buton alows for the torquelock to work and changes the RPM's a which the tranny shifts. Which by the way is well done and very worth while in my opinion. On my last trip out towing a 15,000# 5'er I tried downshifting one notch and the RPM's went right into the 3000+. I didn't keep it there long enough to see exactly how high they went.

You can drop out of overdrive by engaging T/H; then apply braking. This will drop a gear but as soon as you accelerate about 5 mph the tranny will shift back into O/D.

The system works seamlessly and automatically. I love it.

My only bitch about the whole setup is that if you're coming down a steep grade with a curve at the bottom you'll want to reapply the brakes and sometimes this causes the tranny to downshift into second. This REALLY shoots up the RPM's and scares the crap out of me. I don't run my truck that hard and don't want to. I just disengage the T/H; the truck picks up a gear, re-engage the T/H and away I go.

 

Thanx sanpanchosue,

I stand edumucated, and hope this has been helpful for Bhammer.

In theory the TorqueShift sounds great. But I think there's still too much shifting going on. I'll stick with my ZF6.

 

I pull a 10,000 lb travel trailer . And I use the tow/haul mode when I do . The way I see it the engineers designed the tranny to utilize this feature . I guess if your not towing much weight you dont need it . But while using tow/haul there is not much strain on the tranny . IMO

 

I only use my tow/haul when I slow down. I really don't like it for some reason, I am not saying its bad but I don't care for it. Plus everything around here is very flat so I don't see a need. When I pull a load through the hills I might use it, but I've pulled 15K loads in OD with tow/haul off and no probs.

 

Tow/Haul mode does not disable overdrive in any way. It increases the delay between shifts, up and down when pulling. It helps to prevent the "searching" that many of us did not like about the 4R100. That is the trans will hold a gear longer while pulling and when it does shift it will delay shifting back up longer when you level out or back out of the throttle a little. It provides much better engine braking through use of the torque converter and gear selection. The torque converter will not lock up until you have reached a preset RPM and have the throttle input below a certain point and it will unlock quickly upon heavier acceleration or loss of speed. I have heard reference to a "brake clutch" but have not seen any proof of it and do not have the manual in front of me to verify it. I do know that the trucks I service at work are loaded at anywhere from 15,000 to 19000 lbs every day before loading in the days materials and hooking up trailers. I work on utility equipment and we install aerial buckets and even small digger derricks (yes cranes even) on F-450's and F-550's and of course larger trucks. I have driven one that weighed 17,800 and hooked up a 11,000 lb trailer to it and pulled a 6% grade for 2 miles at 70 mph. I think they do a fine job, the only bad part....the auto tranny likes for the engine to roar at the max HP area when pulling hard at full throttle. Bottom line, this is why I figured out a way to make the trucks to go into T/H when they start up, they need it all day every day, they are never unloaded. It has helped the few that I have actually performed this on, they have run about 1/2 again as long on the original brakes as those that don't have the mod. Use the T/H option if you are pulling a load and want the trans to last the life of your truck, that's why FMC went to all the trouble to design and implement it. Remember it is for Towing and HAULING and if it's for hauling then shouldn't it be engaged when you increase your vehicle weight by the hauling capacity?? I haven't seen an actual recommended T/H engaging weight from FMC, has anyone else? 1500 lbs is my trucks carrying capacity by the registration, so does that mean that when I'm hauling something in the bed I should use T/H??? In fact, I do. A load of gravel is a lot easier to slow down when the tranny and engine are helping. Sheesh, I'm long winded, sorry guys I'm goin now.

 

thanks guys that was a great help. This forum is a wonderful thing.

 

Now you guy's got me confused. I used to have a 02, V-10, auto 4R100 and read here and on the owners manual, not to tow in over drive. When I towed my TT, I always turned off the OD, to keep the tranny from "hunting" and it seemed to work fine. When on level ground, I did put it in OD for a short period, to see if the tranny would be okay and it was. Now, I have an 04, PSD, TS auto and towed last summer with the auto in normal (I need to read the dashboard tranny display) which is 4th gear? or OD? I towed all the way to the high mountains and all around streets and freeways with tranny in normal and TS in Tow/Haul on and it worked sweet! So am I supposed to leave it in 3rd when towing and the Tow/Haul on? I can't imagine running around in 3rd all the time, as this is a very high gear.

 

Just drop it into Drive/Overdrive, push T/H (or not), and go. Everything else will take care of itself.

 

Thanks, that's what I figured.

 

You cannot manually select 4th gear. It's either 3rd or 4th/5th, like the old 4R100's were either 2nd or 3rd/4th and you could lock out 4th (overdrive). Now you don't lock out overdrive, you change the parameters that the computer commands each shift and TC lock/unlock at. Unless you are off-road or towing an EXTREMELY heavy load very slowly on rough terrain, you should not need to select a lower gear. It really works well on it's own as you have noted during your use. I had a 02 F-150 with the 5.4L and auto and it would shift to 2nd on it's own pulling up any grade with my 5000 lb trailer and I always turned off o/d when towing. Needless to say, I like the TS much better. Sometimes I still wish I had gotten the 6 spd if for nothing else than the extra mpg.