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Discussion Starter · #1 ·
2003 dakota v-6 auto 4 wd. When it shifts down on a hill the shift just about rips your head off. Turning off o/d doesn't seem to help at all.
 

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2003 dakota v-6 auto 4 wd. When it shifts down on a hill the shift just about rips your head off. Turning off o/d doesn't seem to help at all.
That would be a hard shift for sure.
Is it just the downshift on a hill occurring when the O-D is applied that is
harsh and not the upshift? (3->4)? You say it still occurs with the O/D disengaged, then it has to be a 3->2 downshift
issue. (4->3 downshift or 3->4 upshift) is automatically done by the transmission electrical control, by PCM controller normally. If that is not working correctly, pressure build up will eventually force a downshift (or upshift) as the case
mayb be. There are several transmission valve body components involved:
The 3-> 4 shift valve, 3-> 4 quick fill valve, 3-> 4 timing valve, lockup valve, and the lockup solenoid and overdrive solenoid, both controlled by the PCM.

It may also be the TPS sensor, but that can be checked easily to see if it malfunctions.

There are several transmission components involved in 3->2 upshift/downshift, but the manual says that
harsh 1->2, 2->3, 3->4 OR 3->2 shifts, is due to a lockup solenoid malfunction.
It suggests to remove the valve body and replace the lockup solenoid.
but first you need to be sure that is basically what is happening.
 

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Discussion Starter · #3 · (Edited)
where is the valve body.

Where is the valve body? It only happens going up hills, It's impossible to drive it in cruise control because it happens so abruptly. And taking it out of overdrive does not do anything, I'm not convinced o/d actually works. A used truck that has had nothing but problems.
Thanks
 

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Where is the valve body? It only happens going up hills, It's impossible to drive it in cruise control because it happens so abruptly. And taking it out of overdrive does not do anything, I'm not convinced o/d actually works. A used truck that has had nothing but problems.
Thanks
The control valve body is inside the transmission.
I don't know what model of automatic your vehicle has..42re or 44re or 46re? but the transmission model is located (stamped) on the left side above the removable transmission oil pan.
This is the pan that the garage removes to change the filter and drain the old fluid.

The Chrysler transmission is a complex unit, consisting of two planetary
gear sets, a torque converter and an overdrive unit. The modern ones
that the Dakotas use is based on the Chrysler torqueflite design.

The working parts (besides the planetary gear sets) and torque convertor/
oil pump is:
Front band/front clutch
Rear band/rear clutch
overriding clutch/direct clutch
and of course the governor unit that has a governor solenoid and a
fluid pressor sensor/temperature sensor.
The operation is complicated, but basically the transmission has a
series of valves and servos to operate things like clutches and bands
to allow the double planetary gear sets to shift gears.

Generally speaking the PCM controls the shifting based on your driving
habits and engine rpm, there are 3 solenoids in the transmission
1. variable force solenoid
2. 3-> 4th shift solenoid
3. TCC solenoid (Torque convertor clutch)
The PCM controls all these.

plus

Automatic transmission (A/T) pressor sensor
A/T temperature sensor
Both of these provide signal to the PCM

If there is a problem where the PCM cannot provide the control, fluid pressure and failsafe fluid ports
force a hard shift..but this is hard on the transmission.

Here is a guide to the Chrysler automatic and it's various parts/subassemblies as explained by Tom Hand. In it, he shows
pictures of the various subassemblies.
http://www.allpar.com/mopar/transmissions/torqueflite-tom-hand.html
 

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Turns out over drive works. But still very harsh shift uphill when turned off.[/QUOTE]

The overdrive is a separate unit, controlled by a solenoid and some clutches.
On the 46re transmission (on mine) the shift into overdrive
(4th gear which is a reduced o/p shaft to input shaft gear ratio) is controlled by:
Front clutch; Rear clutch; overdrive clutch.

So I presume from the clutch and band application truth table, that
the front clutch (controlling the front planetary gear set) and
the rear clutch (controlling the rear planetary gear set) and the overdrive
clutch all play a part in achieving overdrive.

If the transmission will not shift into 4th gear, the control switch (on the
turn signal stalk), the overdrive solenoid or related wiring may also be the
cause.

So you need to determine through a process of elimination which
transmission unit is at fault in your casem and you have determined (I presume here)
that it's the 3-4 shift on a hill, where the engine rpm is dropping off due to the extra
load on it while in O/D?

The overdrive unit components are listed in brackets ( )

With transmission in Drive;

shift lever transmission clutches and bands ( overdrive clutches)
|
V
reverse: front clutch & rear band applied (direct clutch applied)

D (1st): rear & overrunning clutch applied (direct overrunning clutches applied)

D (2nd): front band & rear clutch applied (direct clutch& overrunning clutch applied )

D (3rd): front clutch & rear clutch ( direct clutch & overrunning clutch clutch applied)

D (4th) ** : front clutch&rear clutch applied ( overdrive clutch applied)


So from this truth table, you can see that it's a bit more complicated to
diagnose what component(s) are causing your hard pressure UP shift problem.

If the transmission fluid has not been changed and the mileage is getting
up there, perhaps that has something to do with the abrupt shifting?
At what mileage was the tranny last serviced?

My manual says for:

"NO 3->4 Upshift"; possible causes may be:
1. O/D switch in OFF position
2. Overdrive circuit fuse blown
3. O/D switch wire open or shorted
4. Distance or coolant sensor malfunction
5. TPS malfunction
6. Neutral sense to PCM wire open or shorted
7. PCM malfunction
8. Overdrive solenoid open or shorted
9. Solenoid feed orfice in valve body blocked
10. Overdrive clutch failed
11. Hydraulic pressure low *
12 Valve body valve stuck ***
13. O/D piston incorrect spacer
14. Overdrive piston seal failure
15. O/D check valve/orfice failed ***

For delayed 3->4 upshift (slow to engage)
1. Fluid level low
2. Throttle valve cable mis-adjusted ****
3. Overdrive clutch pack worn or burnt ****
4. TPS faulty ****
5. Overdrive clutch bleed orfice plugged ****
6. Overdrive solenoid or wiring ****
7. Overdrive excessive clearance
8. O/D check valve stuck ****

**** most likely

For harsh shifts 3-4 Lockup solenoid malfunction (remove valve body and replace solenoid)
 
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