Tow/haul vs. downshifting

[SMoaB]

Thanks

[Viejo]

Ya - the diesel can be shifted out of overdrive and downshifted further if necessary, but I'd still like to have the automatic downshift and more aggressive engine breaking and a locking torque converter.

[carringb]

Drive it whichever way you like best. You won't hurt the transmission or the brakes. The newer vans have pretty robust brake systems that last a long time.

As for revving way up.... 3k isn't really that fast for the V10. I'll top 5,000 RPM for 10+ minutes sometimes, when I'm moving 22,000+ pounds up a 7% grade at 65 MPH.

[OttoVolcomSMB]

I have a 5.4 v8 and I have the button on the shifter. It is like overdrive on/off. Push it and it goes into fourth gear and yes it keeps rpm up longer before shifting up or down. I notice while driving up the Cuesta grade if I push it it makes me go slower but I can climb up the grade without downshifting into second which is better on the tranny. Keeping it in fourth and third is much better and when driving down yes it doesn't slow me much but it keeps the rpms up a bit and I brake but only lightly. Hope this clears up questions.

[BroncoHauler]

BTW, this would be a great excuse to add transmission temperature monitoring for everyone who doesn't currently have the capability.


Herb

[Gnarvan]

Originally Posted by OttoVolcomSMB

I have a 5.4 v8 and I have the button on the shifter. It is like overdrive on/off. Push it and it goes into fourth gear and yes it keeps rpm up longer before shifting up or down. I notice while driving up the Cuesta grade if I push it it makes me go slower but I can climb up the grade without downshifting into second which is better on the tranny. Keeping it in fourth and third is much better and when driving down yes it doesn't slow me much but it keeps the rpms up a bit and I brake but only lightly. Hope this clears up questions.

Are you saying the overdrive on/off button changes the shift points in the tranny as well as kicking you out of overdrive in the E4OD transmission?

[OttoVolcomSMB]

It seems to for me. I'm not sure about the e40d if that's what I have then yes I do believe it does. I usually don't push it until I'm coming off the freeway or down or up grades. And I drive with it off around town.

[86Scotty]

Originally Posted by BroncoHauler

Tow/Haul is a control on the end of the transmission lever stalk. Believe it was only available on the V10's in the vans. Diesels had the overdrive deselect on the end of the transmission stalk.


Herb

the 5.4s have it too, and I think I've seen some 4.6s with it. I thought it had more to do with the year than the engine, but I've seen it in lots of vans. And it sure does help the smaller v8s!!!

[BroncoHauler]

Originally Posted by 86Scotty

the 5.4s have it too, and I think I've seen some 4.6s with it. I thought it had more to do with the year than the engine, but I've seen it in lots of vans. And it sure does help the smaller v8s!!!

Could be, but I was disappointed never to find it with the diesels.


Herb

[carringb]

Tow/Haul was/is only available with the V10 in the vans, and also with the 5.4L in the cutaways.

It is not the same as OD-off. Tow/Haul changes shift point, shift pressures, and provides automatic downshifts when descending grades when using cruise control, or will downshift 1 or 2 gears depending on brake pressure.

There is nothing different between the 5R110 in the diesels and V10, except the diesels got OD-off because that's what Ford's big customers wanted. It is purely a programming difference, theoretically could be turned into a Tow/Haul button (or vice versa) with a programming change. Except it's not something published, and I'm not aware of anyone that offers that service.