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Discussion Starter · #1 ·
I recently installed a BD valve body and my 48re started hanging up to around 2100 RPM between 2-3 under light throttle... under heavy it shifts great. Now today, I just put in a Borg Warner solenoid and OEM pressure sensor figuring that's where the problem was coming from, but it turns out that was a waste of money because the problem is still there...

What the heck could be wrong? Could it be the valve body itself?
 

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What tear truck? Have you run pressure test? Lots of things can cause this including a bad VB build. Pretty much can't help if we don't know what it is and what you have for pressures.
 

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Discussion Starter · #4 ·
Sorry man, forgot that info... It's and 07 5.9 2500. It has a 4" tbe, smarty, quadzilla module, s&b intake manifold and intake. And I haven't done a pressure test? Is that something the tranny shop should do? And what should the numbers be?

Thanks for the reply!
 

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You need to check your front band adjustment, it could be as simple as its a little too loose.

Set the Smarty back to stock and see if the problem changes. If you are running reduced TQ management with the /smarty the shift points will not be correct at low throttle without either advancing the TTVA motor or running a shift enhancer.

You could do the pressure test or the trans shop. The FSM has the specific test but an updated VB has different pressures. What you need to look at is apply pressures at an idle and WOT, apply pressure ramp as oppesd to gov pressure and wheel speed, pressures in the front servo, and gov pressures opposed to hweel speed and throttle opening.
 
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Discussion Starter · #7 · (Edited)
WHAT THE HECK?! I returned the smarty back to stock and it shifts great!!!

...what does this mean? Am I going to still be able to run the smarty?

EDIT: Under Medium throttle it shifts perfect... Under very light it'll hang a little and start shuttle shifting between 2-3. I just replaced my transducer and solenoid, so I have no idea whats going on...
 

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(snicker) Thought that mught be your issue. :)

Here is the problem, the 05+ trucks have the TTVA motor with a single non-adjustable program on them that ramp TV pressure based on a predertimed map of APPS readings. Whne oyu out a Smarty or other programmer on that changes the fueling curves you now have more fuel with less throttle position. All the preset shift points are now faulty because it takes less throttle to get to the same speed and under light\normal throttle gears seem to hang until you push it a little harder.

Under hard acceleration it is fine because hard throttle is past the presets and it just uses a default high value to determine shift and lockup.

What you need is as I suggested, a shift enhancer to ramp the TTVA program faster with less throttle to compensate. The other thing you can do is remove the TTVA motor, turn it upside down, remove the bottom cover, and advance the the gear thta drives the TV pressure 1 tooth. This gives you more initial advance TV pressure and a faster ramp to where the balance between TV and gov pressure is closer.

Works great on mine with the GM solenoid conversion. You will feel firmer and more frequent downshifts as you slow but its nice to know where the trans is actually at form my view.

BTW, the TTVA motor tweak is free where shift enhancers are $200-250. ;)
 
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Discussion Starter · #9 ·
That makes sense... So it's best just to run the truck on stock programming for now? Would messing with the TQ management settings on the smarty do anything? Also, this just started happening after the VB, why now?

And I already feel the frequent downshifts when slowing down lol. Would that mod fix that little 2-3-2-3 shift I was getting out of the feather throttle?

I appreciate all the help!
 

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Yep, that should fix the shuttle shift and hopefully allow you to run up to TQ management 3 on the Smarty. Other variables contribute but try 3 and drop to 2 if it is still a problem.
 

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Discussion Starter · #11 ·
alrighty, i tried SW3 and TQ man at 3 and it's exactly like stock! It still hangs up (feels like it needs to shift :banghead:) to around 1700 RPM/27-30 MPH, but that's a lot better than 2100 RPM/35 MPH. To make it go completely back to normal, I'd need to do that mod or do a shift enhancer, correct?

Is a shift kit the something as a shift enhancer?

Sorry for all the questions man, I'm trying to learn haha... And that little smarty fix was genius!
 

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Yes, or reduce TQ management to 2.

A shift enhancer ties into the TTVA motor and over rides the stock program so it ramps pressure faster. Its seprate from what a a shift kit does.
 

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That can happen also, its not a hard and fast rule. Every truck is a bit different in how they react.
 

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The TTVA motor sits right on top of the VB shift tower. Drive side of trans right above where the shift cable connects to the shift lever. Alll they did was replace the TV cable with a motor that runs on a PWM signal to adjust TV pressure by turning the same shaft the cable did.
 
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Depends on which setting you use on the shift enhancer. A good will have 3 setting sthat cna be tuned. Daily, tow, and race. The daily tune should advance the TV pressure faster to compensate for TM but maybe not as high. Tow will advance higher but maybe not as fast so it holds the shift point longer at high throttle. Race will go even farther to hold the hsift and get the most out of the range.

These things shift too soon in the lower gears then hang at the top if things are not right. Its an attempt to correct that.
 

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Discussion Starter · #19 · (Edited)
Dodge 48RE Pressure Enhancer BD Diesel 1030348

So this thing should fix that little hang up, right?

More details, I've noticed cruising at 15-16% throttle the RPM's will hang at 1550-1600/25 MPH and won't go any higher unless I give it a bit more juice. Still a symptom of this lack of pressure?

I know before the VB I was able to accelerate at >10% throttle with no problems what so ever.
 

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It definitely sounds like that is a symptom of the VB build. TV pressure is not high enough in relation to gov pressure to shift it.

I would try the TTVA mod first and see if that will do the job then decide if you need the Shift Enhancer. Some times advancing the gear one tooth on the TTVA makes all the difference.

You can get the shift enhancer and it will probably address the issue, just no guarantees though as every truck and every trans build is slightly different.
 
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