Least detrimental gear for WOT

[Aftershock00]

Just seeing if I have anyone else to bite....
aside from debating whether it’s beneficial to go WOT, as the topic headline says, what would everyone say is the least detrimental way to go WOT and have some fun with the truck when it’s empty???

 

[Cummins12V98]

EB yes, TH is optional especially on a empty Truck.
Some like it, some not - to me it turns way to high in TH without a load on it.

I like them both but I suggested he did the TH especially since he likes to get on it and it will be more responsive in TH.

 

[Wiredawg]

I'm going to take another shot at this... I would stay WOT until I hit the speed limit or what you feel comfy with. The best place to dio this is getting on the interstate. Our highways here in TX have 75 to 85 MPH speed limits. I wouldn't think flooring it and immediately getting off it would promote longevity of the turbo, transmission, or the driveline.

That may be MORE in line with what you're talking about.

Have fun, Ron

 

[Aftershock00]

Well not immediately letting off... just letting off right before the transmission is going to shift from 2nd to 3rd. My logic is that the transmission is not making a shift under WOT load, but 0-40% throttle instead. No?

 

[Wiredawg]

Well not immediately letting off... just letting off right before the transmission is going to shift from 2nd to 3rd. My logic is that the transmission is not making a shift under WOT load, but 0-40% throttle instead. No?

AS OZZY PREVIOUSLY MENTIONED, The transmission has torque management that prevents full power at shifts. Imagine you are passing an 18 wheeler on a two lane road or getting on the interstate with one of TX 50ft acceleration lanes and heavy traffic. Pretty much heavy if not WOT.

I'm not WOT, but rolling heavy into my 17 5500 with 5th wheel sometimes when getting on busy interstate or moving into traffic.

I still think your technique puts more stress backing off as the truck is about to shift... just my opinion.

Cheers, Ron

 

[Ozymandias]

Like i said.

 

[TFucili]

I had two Ford transmissions that would make a horrendous screech if I lifted as they were about to make an upshift during hard acceleration, as in the on-ramp scenario above. The one I owned(2000 Expedition)failed catastrophically at very low miles. The other I did not own(2003 F-150)got progressively worse, and fortunately the truck went away before I had to deal with it.

 

[Cummins12V98]

Well not immediately letting off... just letting off right before the transmission is going to shift from 2nd to 3rd. My logic is that the transmission is not making a shift under WOT load, but 0-40% throttle instead. No?

Just drive it!

 

[Ozymandias]

It even drops in the TC clutch at WOT, so yes, it shifts gears always when needed.

 

[Aftershock00]

So two guys here staying from either experience or a gut feeling, that letting off throttle after being deep into it right when it’s about to shift isn’t the greatest for the life of the transmission. I tend to agree that the transmission spazzes out with confusion / hesitation when I do this, but I’ve been driving manual for most of my life so I figured this is just how autos are. Any transmission gurus that can provide some technical explanation to this ?

 

[cerberusiam]

If the shift programming is correct then you should never need to lift at shift points. The TCM will auto defuel to limit the TQ and slip the TC clutch as it shifts. WOT on stock tunes gains you nothing, that 75-80% throttle gives you. If it does actually unlock the TC you don't want that anyway so train yourself to go about 75% throttle until you speed is over 60 mph and do not lift off the throttle as it runs thru the gears. You should never lift suddenly anyway unless it is an emergency, roll into and out of the throttle will be a lot easier on the the drive train and keep the confusion in the TCM to a minimum. You should have a manual shift mode on the trans anyway, if you want more control use it. If you want more control add the console shifter so you can get the auto stick option working.

 

[Cummins12V98]

Use the toggle on the shifter if you want, hell even run it til it de-fuels and then up shift it simply won't hurt it's self. BUT if you are hammering it and rapidly let off just as it's ready to shift I don't think the computer can compensate for such behavior.

 

[TFucili]

I should clarify that my example above is not how I drive, but there are circumstances where you are trying to get up a head of steam, and someone in front of you balks, or someone makes an errant lane change that forces you to jump out of it, and that is what lead to the Fords screeching.

 

[Aftershock00]

If the shift programming is correct then you should never need to lift at shift points. The TCM will auto defuel to limit the TQ and slip the TC clutch as it shifts. WOT on stock tunes gains you nothing, that 75-80% throttle gives you. If it does actually unlock the TC you don't want that anyway so train yourself to go about 75% throttle until you speed is over 60 mph and do not lift off the throttle as it runs thru the gears. You should never lift suddenly anyway unless it is an emergency, roll into and out of the throttle will be a lot easier on the the drive train and keep the confusion in the TCM to a minimum. You should have a manual shift mode on the trans anyway, if you want more control use it. If you want more control add the console shifter so you can get the auto stick option working.

Thank you very much for the response. You take a stance and back it up with a detailed explanation. The forum nazis must be losing their mind.

Being a MT guy mostly, I didn’t know these details on the auto. What you say makes sense, I will try to do that going forward.

I did feel like something wasn’t right when I abruptly let off, transmission seemed confused/lost and then a gear would lock in not with a bang, but noticeably more harsh than a standard upshift.

As another guy mentioned, living in socialist Long Island NY, our highways get packed. Even in rush hour before traffic actually slow, the step before that is traffic still moving at 65-75 in a 55, but all vehicles including trucks are up each other’s asses... one or two car lengths apart. On top of that, on ramps can be very short. Do you have to build up speed very quickly and time your “slot” perfectly. This usually requires you go accelerate hard 75% throttle, and then instantly go from accelerating to a speed, to maintaining that speed, and sometimes even slowing down from that speed, which often ends in an abrupt dethrottle. I figured this has to be a common occurrence and part of rams R and D, so I didn’t think that doing that same thing for recreation would be that bad...

It’s good to know that I should try, within reason, to avoid going from large load to no load scenarios.

 

[Ozymandias]

There is a difference doing it from time to time because it is needed or doin it all the time for no reason.
The 68RFE is a very sophisticated transmission and prevents itself from abuse most of the time, there isn't much YOU can do to actually harm the drivetrain on a stock Cummins Ram Gen.4

 

[Aftershock00]

So other than revving it to Wot and dropping it into D, this transmission is abuse proof ?

 

[AH64ID]

So other than revving it to Wot and dropping it into D, this transmission is abuse proof ?

No... you still can’t drive it like an idiot.

WOT shifts aren’t an issue, working the throttle like a light switch is.

 

[cerberusiam]

There is a lot you can do to destroy it with just stock power, not even a question there. No brake stands, use TH, roll into and out of the throttle, only use WOT when speed is up, no excessive throttle work or like John says "like a light switch". If you want extra safety and updated VB and a trans tune will help a lot.

 

[Ozymandias]

So other than revving it to Wot and dropping it into D, this transmission is abuse proof ?

More or less yes, like the others mentioned, drive like an idiot wont help for the longevity of the Trans. But driven with just a little knowledge about how it works you can't harm it.

The predecessor was way more picky about that because it was more or less mechanically and drivers input was crucial to it.

The 68 safes itself from abuse 99% of the time because it is fully integrated into the Drivetrains Electronic Controls. And you can be sure that Ram programmed it to not destroy itself in a minute.
That's what people are complaining about, Torque management, defueling, throttle lag and other things.

 

[Aftershock00]

Thanks guys, really learning a lot about today modern trannys, especially today’s electronically integrated ones such as the 68rfe.

My throttle on is more of a dimmer switch, my throttle off is more of a light switch, so I will adjust my driving habits accordingly.

I smelled transmission fluid the other day... smelled fine, not burnt. Any way to tell if I did actual damage by driving like this every so often ? Obviously I can’t change what’s done, and I have a warranty, but it would be nice to know when driving 6 hours away, in the middle of nowhere, at 2am, if I have to worry about the transmission going boom/clunk/bang without warning. Never had a transmission fail on me, except once, with 300k miles on it, and that have a long drawn out warning getting progressively worse for thousands of miles.