Forums
Forum Tools
|
 |
03:13:24 - 04/28/2024
General Dakota Board
| From | Message |
blued
Dodge Dakota
JOIN HERE
6/09/2002
23:55:41
|
 Subject: Tranny Problems a little help please
IP: Logged
Message:
Ok here's what is happening what do you guys think it is?
I have an Automatic transmission in my 1999 D with a 5.9. It runs good and I keep it well maintained. The transmission has starting to fluctuate about 200 - 300 Rpm when cruising around town or going to work (thats about all the driving I do) It does it in both OD and when I turn OD off. I will be cruising at say 60 at about 2000 Rpm and if I engage cruise control it acts as though the converter is slipping or the lockup is locking then unlocking it will drive for a couple of seconds then rev up to about 2300 then a couple of seconds later it will drop back to 2000 (it repeats this on end until i get aggrevated and turn off the cruise). I try driving without cruise and it still does it although I can eliminate part of it with delicate throttle pressure (I dont like delicate throttle pressure at all). This problem has gotten worse and I am ready to take it to Dodge but want to have a leg to stand on before talking with the most stubborn ignorant people on Earth. Sorry for the long post and thanks in advance for the help. By the way I have only done Catback exhaust and K&n intake as mods so it is still close to stock and I have no real elevation to cause downshifting around here there isnt a hill in the whole dam. panhandle of FL
|
bernd
*GenIII*
 
6/10/2002
00:03:11
|  RE: Tranny Problems a little help please
IP: Logged
Message:
Governor Pressure Solenoid. (Definitely sounds like it and have seen this happen quite often.)
1997 Dodge Dakota SLT - V6
Supercharged/Intercooled @ 10# w/Nitrous
14.55 @ 96.01mph
|
blued
Dodge Dakota
JOIN HERE
6/10/2002
00:07:03
| RE: Tranny Problems a little help please
IP: Logged
Message:
Thanks bernd.
Man you really know your stuff on these.
I have the extended warranty with the 100 dollar deductible which is the better way to go get the part myself or take it to DC and have them put it in and be out the 100 bucks???
|
blued
Dodge Dakota
JOIN HERE
6/10/2002
16:40:27
| RE: Tranny Problems a little help please
IP: Logged
Message:
in addition to the above does anyone know some good ways (other than going to a 5 speed) to improve the efficiency of these automatic trannys. Seems a good way to "add" rear wheel horsepower would be to get what you are already making at the crank, to the rear wheels a little better.
|
blued
Dodge Dakota
JOIN HERE
6/10/2002
23:18:31
| RE: Tranny Problems hmmm!!!
IP: Logged
Message:
Contacted the service department at Dodge today and they said they would take a look at it on Wednesday, hook it up and run some diagnostics blah blah blah. It is uder the extended warranty so I am going to have to pay for the "look at it" to the tune of 65 bucks grrr. Oh well we shall see what comes of it. I hope the delership here in Pensacola is more knowledgable than the ones back home!!!
|
jj
Dodge Dakota
JOIN HERE
6/10/2002
23:45:11
|  RE: Tranny Problems a little help please
IP: Logged
Message:
Good call bernd,my buddy`s jeep was doing the same and it was the gps or pressure modulator,heres some info I pasted ,very insitefull about the dodge 45rfe,jj
V8-equipped Grand Cherokees, Durangos and Dakotas, Chrysler's new 45RFE transmission features fully electronic controls coupled with the ability to adapt to normal wear and tear.
--------------------------------------------------------------------------------
Remember the little red wagon that carried us through imaginary traffic and trails when we were young? A little pull on the front or push in back and we were on our way. Younger guys might remember the so-named little red wagon Dodge pickup trucks. These trucks were still toys...but they were serious V8-equipped toys.
Now, for those who like combining hauling ability with gutsy V8 nostalgia, there's good news: First, the V8-with its throaty, eight-cylinder power rumble-is still available. Second, it's put in new Chrysler Corp. sport/utes and compact pickups and coupled with a new, highly efficient automatic transmission underneath...that's electronically controlled!
What's this new transmission-the 45RFE-all about? Functioning behind the 4.7-liter OHC V8 found in late-model Jeep Grand Cherokees, Dodge Dakotas and Dodge Durangos, the transmission serves up four forward speeds and a reverse gear. But shifting is controlled differently from the hydraulic valves, switches and solenoids of older Torqueflite units. This new transmission Chrysler terms a four-speed, torque level five unit. The RFE designation following the 45 nameplate numbers stands for Rear Wheel Drive and Full Electronic control. The 45RFE is quite similar in operation to the FWD Chrysler 41TE (A-604) and 42LE (A-606) transaxles.
Operation
With the 45RFE, an electronic Transmission Control Module (TCM) mounted in the engine compartment keeps tabs on such items as engine power, rpm and vehicle speed, then adjusts the transmission shift points and shift feel accordingly. Also, like a sibling sitting in a little red wagon, the TCM communicates these inputs to its big brother underhood-the PCM.
From the torque converter, engine power turns the new tranny's input shaft and spins an input clutch housing. The clutch unit houses underdrive, overdrive and reverse clutches. Moving toward the rear, we find a center support area that introduces us to the holding clutches (the 2nd and 4th gear clutches). Note that no internal brake bands squeeze tightly to stop the spinning drums in the 45RFE. Instead, several braking clutch units halt the spin of the gearset components. As a result, there are no band adjustments needed, no apply servo covers to leak and no apply piston pin bosses to score.
Rearward of the gearset assembly, the low/reverse clutch and the low one-way roller clutch housed in the back of the case take on the holding responsibilities.
Notice that we omitted telling you about a 3rd gear clutch unit. That's because 3rd gear occurs as the underdrive and overdrive clutches start moving the load together. This provides a 1:1 drive ratio in the gearset.
To arrive at the other gear ratios available, the clutches apply in different combinations of two clutch packs at a time, using one driving clutch and a holding clutch-that is, except in Park or Neutral, wherein only the low/reverse clutch applies. Park and Neutral may be likened to holding a little red wagon's yoke without leaning forward to apply the pulling power.
One really nice feature on the 45RFE is an additional 2nd gear! Usually called the 2nd prime, this gear comes into play when both the underdrive and 4th holding clutches kick in to move the vehicle along. It happens during downshifts that occur above certain vehicle speeds. The 2nd prime function livens up performance by grabbing a high-ratio passing gear.
So Goes Tradition
The 45RFE drives via three simple planetary gearsets rather than the normal sun gear compound Simpson gearsets used in Torqueflite predecessors. The three 45RFE gearsets found behind the center support provide a deep Low and Reverse ratio and Overdrive. Therefore, this transmission doesn't need an add-on overdrive unit to haul butt.
From its mounting in the engine compartment, the TCM rides point for the transmission function. Remember, the PCM doesn't control the transmission; it merely receives information from the TCM about how the drive is going.
The TCM receives power from two sources: The first is the fused battery voltage supplied to pin 56; the second is the ignition switch signal supplied to pin 11. Distributing the voltage accordingly, the TCM uses the tranny's various sensors and switches to determine the needed gear ratios and shift points. The TCM also has a circuit ground to complete its control loop.
The TCM control signals aim at a line pressure control solenoid and six shift solenoids. These are found in a transmission range-sensor assembly fastened to the hydraulic valve body. The solenoids vary slightly in design and operation; some are normally vented at rest, while others are normally applied.
Hearing the Call
Various input sensors give information to the TCM regarding gear selection and the needed pressures. You'll find both the input speed sensor and output speed sensor on the left side of the transmission case. The input sensor is located at the base of the bellhousing and reads the input shaft speed from an internal tone wheel, similar to what you'll find at the wheels of an antilock brake system.
The TCM compares the input speed sensor input with the output speed sensor signal. The output sensor also reads from a tone wheel driven by the tranny's output shaft. It's located at the left rear of the case, just ahead of the output housing.
Comparing the two speed signals provides gear ratio information to the TCM, while the crankshaft position sensor passes along info regarding engine speed. All these signals are necessary for scheduling the appropriate shift point occurrences.
The 45RFE's line pressure sensor is located at the right rear of the unit. This sensor changes resistance to supply hydraulic line pressure information to the TCM. Pressure from the transmission's oil pump builds as soon as the engine spins the converter and its hub.
The 45RFE also makes use of a transmission fluid temperature sensor located in the solenoid unit. This sensor is a common thermistor, which changes its signal to the TCM based on the temperature of the fluid.
The solenoid pack/transmission-range sensor (SP/TRS) houses five switches that communicate with the TCM by sending various combinations of signals, depending on the position of the manual range selector. These switches apply different inputs to the TCM, depending on the gear selector position, and supply a backup-lamp switch signal, as well. The SP/TRS relays its signals to the TCM via a main electrical connector on the left side of the case.
In addition to these switches, five switches access clutch pressure level information in the hydraulic circuits. These monitor pressures for the low/reverse, 2nd, 4th, underdrive and overdrive clutch units. The switch inputs help detect hydraulic pressure loss when failures occur in specific clutch circuits.
Lastly, an overdrive-cancel switch rides on the shift lever so the operator can cancel overdrive operation when conditions warrant it.
TCM Response
Depending on the input signals, the TCM works to govern transmission operation whenever the transmission control relay receives a ground signal from terminal 15, which closes the circuit. With this relay closed, the TCM can operate the solenoids needed.
Most solenoids and their switches simply push or pull to open and control oil pressures. The line pressure control solenoid, for example, is a pulse-width-modulated control valve. Zero pulse width results in maximum line pressure. In normal operation, the valve controls pressure to a hydraulic boost valve, and thus controls line pressure. Usually, transmission line pressure changes with engine torque output, but the line pressure also has a base shift value that occurs just before a shift. The pressure returns to engine torque-response after the shift occurs.
The underdrive solenoid and its pressure switch control the oil pressure apply to the underdrive clutch in 1st, 2nd, 2nd prime and 3rd gears. Also, the overdrive solenoid, with its pressure switch normally vented, controls oil pressure to the overdrive clutch in 3rd and 4th gears. Similarly, the 4th clutch solenoid with its pressure switch is also normally vented. It controls oil pressures supplied to the 4th clutch in 4th and 2nd prime gears.
The 2nd clutch solenoid, with its attending pressure switch normally vented, parlays control of oil pressures to the 2nd clutch in both 2nd gear operations. And lastly, the low/ reverse solenoid, with its attending pressure switch normally vented, supplies pressure to apply the low/reverse clutch in 1st gear from Neutral, or during engine brake coastdown to 1st gear. It also controls oil for the converter clutch.
Finally, there's the multi-select solenoid. This solenoid rides as a normally applied unit and has several functions. It controls the overdrive clutch in 3rd-gear Limp-Home mode, the 2nd gear clutch while the shaft selector lever is in manual 2nd and during 2nd gear Limp-Home and, finally, operates the low/reverse clutch when the selector is in Reverse range.
Electronic Shift Feel
The TCM on the 45RFE has adaptive learning, meaning it can modify clutch-apply rates to control shift quality in spite of friction clutch wear. To do this, the TCM alters the clutch volume index (CVI) when a shift change takes place to optimize clutch engagement. The CVI represents the volume of tranny fluid needed by a clutch to properly compress the clutch pack.
Here's how the TCM alters it: First, the module closely monitors the input speed sensor and output speed sensor signal changes. By comparing the two signals, the TCM figures out the gear ratio. This is important because the TCM determines the CVI calculation by monitoring how long it takes the gear ratio to change. By monitoring this time, the TCM can determine the volume of fluid that was used to apply or release that clutch and update that information continuously, for adaptive control. As a result, as friction discs wear, the volume of fluid applying the friction element automatically increases.
Obviously, mechanical troubles such as broken clutch piston return springs, improper snap ring installations or excessive clutch disc clearances due to worn friction material can cause erroneous CVI readings. And these improper readings can lead to improper shift feel, which just adds to the woes. Note that defective speed sensing and/or poor electrical connections can cause similar problems.
Wagon Whoa!
Through its sensors and connections, the 45RFE's TCM monitors all transmission-related electrical components. If a problem arises, the TCM can set a DTC in memory. Depending on the code set, the trouble light may illuminate or the transmission can go into Limp-Home mode. The TCM does this by cutting off the ground to the control relay, which shuts down all electrical power to the transmission.
Note that when in Limp-Home mode, the transmission will be locked in 3rd gear if the shift lever is in Drive. If positioned in the 2nd or L lever position, the transmission holds 2nd gear. The driver can now shift the transmission manually. Once the wagon is corralled in your service bay, a combination of scan testing, fluid pressure and air pressure testing, plus some special 45RFE tools, should get the wagonmaster on the trail again.
[ Back ]
|
blued
Dodge Dakota
JOIN HERE
6/11/2002
19:25:39
|  RE: Tranny Problems a little help please
IP: Logged
Message:
Wow thats some good info !thanks
|
blued
Dodge Dakota
JOIN HERE
6/11/2002
19:45:19
|  RE: Tranny Problems a little help please
IP: Logged
Message:
I agree but interesting that there are 2 of us out there...(i didnt write the above)
LOL
Just got off of work and read the post really good info on the workings of the 45rfe.
I do think however that behind my 1999 5.9 there lurcks a 46re, correct me if i am wrong, thanks again for all the input.
BLUED (the one and only)
|
rude
Dodge Dakota
JOIN HERE
6/12/2002
21:04:59
|  RE: Tranny Problems a little help please
IP: Logged
Message:
Wow I love people who post a Question,asking for help,then some give advice,and we never hear back,it would be nice to know what happened.and perhaps a thanks for the trying to help.
|
Lesley
GenIII
6/12/2002
22:08:12
| RE: Tranny Problems a little help please
IP: Logged
Message:
Hey guys. I just got my dak back from the shop after having the same symptoms. It was the governor pressure solenoid, and also the transducer. The truck was hunting for gears and shifting erratically. Truck is now 100%.
97 3.9 CC Sport. Black. Auto 3.55, Quick D Intake, JBA Stainless headers, Autolite 3923s, stainless Borla Turbo XL, V8 TB, FMS 19 lb fuel injectors, 17" Boyd Coddington Smoothies. Have, but not installed: JBA 9mm cables, Borla tip, IAT adjuster
|
blued
Dodge Dakota
JOIN HERE
6/13/2002
17:38:06
| RE: Tranny Problems a little help please
IP: Logged
Message:
Hope I wasn't being the "rude one" my baby had been in the shop for the past two days I just got it back about 30 minutes ago. Drives and shifts like a dream now, it also holds steady rpm while cruising. A big thank you goes out to you guys for your insight into my tranny questions.
Just so you know on mine the GPS tested fine however the Throttle Positions Sensor was giving out erratic readings which they said would also account for some stalling conditions that I had noticed in the past. Total bill was $191.16 extended warranty covered 91.16 and I got the deductable. Works great now...
and again thank you all.
|
Bob E
Dodge Dakota
JOIN HERE
6/28/2002
12:20:57
|  RE: Tranny Problems a little help please
IP: Logged
Message:
My transmission has developed a slow and noisy shift into reverse, from both park and neutral. The dealer tells me the same thing he always tells me. "That is normal for a dodge". Any ideas would be appreciated. 2001 quadcab, 4.7 automatic. RWD. 17,000 miles.
|
sandmp
Dodge Dakota
JOIN HERE
3/20/2003
20:03:42
|  RE: Tranny Problems a little help please
IP: Logged
Message:
I have a 2000 Dak/4.7. I have just had the irratic shift problems starting today. The check engine light is also on. I am taking it into the dealership tomorrow. The previous posting are a world of help and I thank all those with the knownledge. When my Dak. gets home, I will post the results.
|
sandmp
Dodge Dakota
JOIN HERE
3/25/2003
22:52:44
| RE: Tranny Problems a little help please
IP: Logged
Message:
PCM went bad, under warrenty thank god.
|
Randy
Dodge Dakota
JOIN HERE
4/01/2003
12:45:36
| RE: Tranny Problems a little help please
IP: Logged
Message:
i have a 97 dakota ,v-8,auto. occasionlly it seems to be stuck in 2nd gear,and the check engine light comes on so i scanned it and brought up a code for "shift solenoid A"...does anyone know what this means and where its located on trany?is this a problem i can fix or does it consist of tearing into the trany? thanks guys.
|
Stoggs
Dodge Dakota
JOIN HERE
5/26/2003
16:25:59
| RE: Tranny Problems a little help please
IP: Logged
Message:
I assume your truck is out of warrenty. I cannot help you with the torque converter, but I would like to let everyone know that if they have problems with thier trucks while under warranty and the dealer fails to fix it properly; after the third try you truck could be covered by the lemon laws. I learned the hard way. I made many trips to the dealer to fix a sloppy transmission shift problem while the truck was still under the factory warranty. I was never fixed properly. Now with 65K on the the truck, the sloppy shift has grown to 2nd gear complety gone - slips like hell.
The result - the dealer says it will cost $2500.00 to fix it! What the @#$%^$#! Stick to your guns if you have a problem which is covered under warranty! Call the Chrysler Care number and pinch a fit! Or else....
|
FT
Dodge Dakota
JOIN HERE
7/01/2003
09:23:55
| RE: Tranny Problems a little help please
IP: Logged
Message:
Did a (transmission failure) search and I am posting here. This might be beneficial to some owners.
We have dozens of Dodge trucks where I work. They were inundated with trans problems. We had so many go down, you would not believe it. And they were all off warranty. I don't know why they have such a high failure rate. I am referring to trucks from about 1990 up to 2001. One of the last trucks I drove at work was a 2001 Dodge. At around 25k miles the transmission started acting up. In the cold mornings it would not engage and shifting was very hard.
I was told by our equipment supervisor, that about 1/2 of all Dodge's will lose the transmission before they hit 5yrs/100,000 miles. On any given day, one of our Dodge trucks is in a shop for transmission repair. The only reason we keep buying them is they are cheap to buy. No body every thinks about the costs to maintain.
I know the owner of a transmission shop, 20+ years in business. He tells me Amsoil is what he puts in all Chrysler transmissions he rebuilds. He says they don't seem to last with the other brands available in the marketplace, and he has never had an Amsoil filled transmission come back ... whereas the Chrysler dealer does. He takes all the dealers overflow and it keeps him busy year round.
|
KenK
Dodge Dakota
JOIN HERE
10/18/2003
10:48:38
| RE: Tranny Problems a little help please
IP: Logged
Message:
I have 2003 and when I step down on the gas to get more power to either pass or to maintain speed up a steep hill I drop out of gear to what seems to be neutral. I get no power and the engines revs really high. The dealer says that the tranny is "confused" by possibly the speed and drops to too low a gear. Sounds like #%*@ to me. I am bringing it back for a second time. Only 23,000 miles and it is all highway. V-6 4WD Automatic.
|
gen1dak
Dodge Dakota
JOIN HERE
10/19/2003
00:18:23
| RE: Tranny Problems a little help please
IP: Logged
Message:
Make that 1989-2001. My A-500 repeatedly fried the overdrive, despite never towing anything. The A-518's fared better since they had larger coolant lines, but all-in-all, ever since the eggheads mucked with the original Torqueflite, they've gone to Hell. Luckily, the fellows in the aftermarket know just what to do and supply kits and valve body kits that elevate these trannies to Torqueflite glory. JVX is a great place for this. You'll pay a lot, but it'll be worth it.
|
ROBERT
Dodge Dakota
JOIN HERE
2/03/2004
11:20:15
| RE: Tranny Problems a little help please
IP: Logged
Message:
I HAVE A 1992 V-8 WITH OVER DRIVE 4X4 DODGE DAKOTA EXTENDED CAB PICK UP .I NEED SOME HELP,MY TRUCK DRIVES FINE WHEN IT IS COLD BUT WHEN IT WARMS UP IT STICKS IN LOW GEAR AND THE RPM'S GO WAY UP.WHAT COULD BE CAUSING THIS????????
|
jared
Dodge Dakota
JOIN HERE
2/21/2004
14:58:46
| tranny.or. overdrive??
IP: Logged
Message:
first time user, seems like a very informitive site.. my 98' dakota 4x4 v8 automatic has a serious issue. o/d off all is fine, but if o/d is on i get a ping or cracking sound from under the hood: speed is 50-60mph, and it starts when i try to accelerate on flat or up-grade. once i take it out it changes to a higher gear and is back to normal! My question, i took it to the dealership when i bought it 1 year ago, and they replaced the distribuator cap, and wires, helpped for a while but does it again; i know i will have to pay for the repair if any, but i have bad feels about my local dealership, should i go back, or find a mechanic i like?
thanks all
|
| | P 1 Next Page>> |
|
