DP Tuner , what are the transmission impacts? - Diesel Forum

DelArmy · 07-28-2008, 10:50 PM

I just installed the DP Tuner and need some help understanding the impacts on the transmission. I’ve got a primarily stock 02 Ford F-250 Crewcab, 7.3L PSD w/F5 DP Tuner with 60hp tow and 80hp economy modules; pyro, trans temp and boost gauges w/100K mileage. I tow a fifth wheel that approaches 12k #. Typically when I tow I turn off the overdrive. With the DP Tuner, should I still be turning off the OD? Second, with the Tuner in tow or economy, shifting is very abrupt and the entire truck shudders when shifting from 2nd to Drive. Would a transmission valve body be in order? Any suggestion of which valve body and where to purchase? Also, is there a DIY post for installing the valve body, assuming that it is the answer to smoother shifts. Will installation of a valve body necessitate reflashing the F5? I’m planning on flushing the trans and installing a larger cooler, so might as well do it all at once. I’d like to hear peoples views on this subject. Thanks!

**SeeYa** · 07-29-2008, 08:34 PM

Quote:

Originally Posted by DelArmy

I just installed the DP Tuner and need some help understanding the impacts on the transmission. I’ve got a primarily stock 02 Ford F-250 Crewcab, 7.3L PSD w/F5 DP Tuner with 60hp tow and 80hp economy modules; pyro, trans temp and boost gauges w/100K mileage. I tow a fifth wheel that approaches 12k #. Typically when I tow I turn off the overdrive. With the DP Tuner, should I still be turning off the OD? Second, with the Tuner in tow or economy, shifting is very abrupt and the entire truck shudders when shifting from 2nd to Drive. Would a transmission valve body be in order? Any suggestion of which valve body and where to purchase? Also, is there a DIY post for installing the valve body, assuming that it is the answer to smoother shifts. Will installation of a valve body necessitate reflashing the F5? I’m planning on flushing the trans and installing a larger cooler, so might as well do it all at once. I’d like to hear peoples views on this subject. Thanks!

DelArmy,

I apologize,in advance but my knowledge is not as indepth for anwering the tuning questions you are asking. Jody would be the best person to answer these questions. He does not frequent the forums and can be better reached by email or by phone. If he typed up what he needs to tell you it would take alot of bandwidth. The site may have to end up updating their servers.

Diane

wittmeba · 08-30-2008, 09:18 AM

I too have a question related to trans shifting.

I bought the SCT Tuner with the 40/80/120 HP tunes couple years back and lived with what I received. Love the added power, but dont like the effects on the tranny.

It seems the trans shifts too early thru each gear. I realize these motors are 'torquers' but it seems they need a few revs too.

Im wondering if this can be altered without a lot of work. I suspect Jody has enough knowledge with these tunes that he could tweak it in the right direction and improve my tune - particularly the 80HP tune. Is this file one that could be emailed and I install in the tuner with the right cable and connectors?

Thanks,
Bruce

**SeeYa** · 08-31-2008, 08:41 AM

For more direct tuning questions like this it would be best to email Jody directly at sales@dp-tuner.com. You will get a much quicker response since he does not frequent the forums.

Thanks,

Diane

indyF-350psd · 08-31-2008, 09:13 PM

a valve body will help the hard shifting. i put a john wood valve body in mine after installing my DP and it cleared it right up. and on the early shifting on the 80hp tune that is the economy tune. thats why it shifts a little early to keep the rpms down thus creating better economy. get a VB and you will like it better.......

bbasso · 01-31-2010, 11:34 AM

To those who have asked questions about the trans and DP, did you ever get any anwsers?
Mind sharing them?
thanks.

GAC · 03-12-2010, 09:50 PM

Just installed the John Woods Valve (Accumulator) Body and it was just what the doctor ordered. Shifts are now firm and no "Shift Flare" from upshifts. Originally thought the tranny was slipping with more than 1/2 throttle due to the extra power from the DP Tuner. Kept searching till I came upon some posts from other members experiencing the same type of issue and labeled as "Shift Flare". Can't speak to the BTS valve body but will give the John Woods Valve Body a serious thumbs up. Picked it up from itpdiesel with a new filter and now I'm on my way.

- GAC

Cowboy Billy · 03-23-2010, 10:05 AM

Actually that hard shift is easier on the trans than the long slow shift.

Car companies tweaked the trans so the shift would feel smooth. But what they did to do that puts a lot of wear and heat into the trans. How they do that is by leaving the gear you are in locked up. Then they start locking in the second gear and slowly release the first gear brake band. What you end up with is two gears fighting each other during the shift. Causing a lot of wear on the bands and gears and heat from the friction of the bands slipping. 25 years ago when the trans had mechanical shifting. We would get what was called a taxi cab kit. That would reduce the slipping and make the shift feel harder. But it would make the trans last longer which is why they came in taxi cabs.

Billy

**Mark Kovalsky** · 03-23-2010, 10:20 AM

Quote:

Originally Posted by Cowboy Billy

How they do that is by leaving the gear you are in locked up. Then they start locking in the second gear and slowly release the first gear brake band. What you end up with is two gears fighting each other during the shift. Causing a lot of wear on the bands and gears and heat from the friction of the bands slipping.

25 years ago that was at least partially true. No longer.

In the 4R100 trans each gear change is made by adding a clutch. The releasing clutch is a one way clutch, which does not have any friction material. It will overrun when the oncoming clutch has enough capacity to make the parts that are changing speeds spin faster. No gear fights another gear.