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Yes, was talking about torque converter seals.

you know, I strongly feel that tranny is coming out..however, when rebuilding 1st and 2nd times, I did look at seals , pistons, no obvious damages.

Probably it is not visually idendifyable.
 

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Good day friends,

Couple of findins.

1. I disconnected the lines going to the oil cooler. Started the car, no oil pressure at all. The oil was just flowing under normal, feels like from the tap. Should it be that way? I'd expect some pressure in those lines... confused

2. Removed main filter, shoved a piece of hose into the pump intake. Started the car. It was sucking some what, put it into D, some flow started to come all around the valve body. This confused me, as I'd expect this system to be closed loop..

2. Did the air test of the OD UD and R clutch pistons. Seems in perfect condition... please see the video. OD moved fast and precise. UD refuses to take, as expected, you can see it pushes the air gun away. R also moved the drum backwards..


pulling tranny anyways..I suspect the pump is not working properly

any other suggestions?
 

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Hi there. I'm a noob when it comes to this stuff so I thought I'd mention that first. I have exactly the same problem as jordantractor except I have a 2014 ram 1500 slot 2wd 5.7 hemi. I was hoping for some guidance before I remove the pan.i have not done the check yet of disconnecting trans harness and driving to see if it goes directly into 3rd. I have auto transmission with the manual button on the shift arm. Any help would be appreciated, it happened suddenly, no warning, and I get only code 0733. I do not get code 0750 which would indicate a bad solenoid pack, is this right? Again, any help would be greatly appreciated
 

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Hi there. I'm a noob when it comes to this stuff so I thought I'd mention that first. I have exactly the same problem as jordantractor except I have a 2014 ram 1500 slot 2wd 5.7 hemi. I was hoping for some guidance before I remove the pan.i have not done the check yet of disconnecting trans harness and driving to see if it goes directly into 3rd. I have auto transmission with the manual button on the shift arm. Any help would be appreciated, it happened suddenly, no warning, and I get only code 0733. I do not get code 0750 which would indicate a bad solenoid pack, is this right? Again, any help would be greatly appreciated
For a sudden total failure of 3rd gear in a 545RFE, I would drop the pan and look at the passenger side of the valve body (the accumulator cover). Odds are you have a blown cover. Mopar sells a repair kit (new cover, with one new piston and new screws). You don't have to replace the entire valve body. If you're lucky (and the OD clutch hasn't been too badly damaged), replacing a blown cover plate will fix it.
 

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Hey transengineer. You were correct about the cover plate. It was bent, I removed the valve housing and ordered the kit. Couple of questions. Does the od piston only have the single spring, the 4 others have double springs....As well, how would I know if the od clutch has been damaged? Thanks again for the help and support. I really appreciate it, learning about these things and saving the money.
 

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Hey transengineer. You were correct about the cover plate. It was bent, I removed the valve housing and ordered the kit. Couple of questions. Does the od piston only have the single spring, the 4 others have double springs....As well, how would I know if the od clutch has been damaged? Thanks again for the help and support. I really appreciate it, learning about these things and saving the money.
Yes, the OD accumulator piston has only one spring. The others have two nested springs.

You'll know the OD clutch is damaged if:
1) You find obvious clutch material (which normally resembles coffee grounds) in the pan or on top of the valve body, or
2) After you fix the valve body, you still get P0733 (or P0735, or P0729) faults.
 

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Hi folks

here are the updates...

Ive re-built the tranny. The OD clutches were gone obviously. Found some more mistakes, that were done from previous re-builts by shop mechanics...so far I promised myself that will take days off and do all the work myself..

Ok, put the tranny back into the car. Fluid level ok. New filters etc. Started, shifted to D. Had delays. It engaged after about 5 seconds or so. This did not make me happy obviously.

So took it for drive, very gentle on throttle. up to 70kmh, 3rd gear shifted ok. After that, bang....again p0733..again same problems.

Came back to yard. Disconnected main harness to solenoid valves...feels like in 1st...

question 1.

Can I burn OD clutches with very gently drive, in total about 5-6miles??

question 2.

When I disconnected the harness, thus cut the power to main regulator valve, which regulates main pressure in valve body, the shift to D was instantaneous. Like it should. In other words, the engagement was instant. For some reason I thing the TCM does not regulate the pressure inside the transmission properly. This could explain why I slip clutches, as it does not have enough pressure to hold em together.

I think the problem is not the tranny any more. As I will keep re-building it and it will burn itself.

Any other suggestions?
 

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one more thing, transfer case position sensor is gone. I've taken it apart I will fix

There was one more JK at the dealers shop, petrol thou. They said it had the same shifting problems and after they changed the sensor it was fixed.

A bit odd for me. But..

Any thoughts on this?
 

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Hi folks

here are the updates...

Ive re-built the tranny. The OD clutches were gone obviously. Found some more mistakes, that were done from previous re-builts by shop mechanics...so far I promised myself that will take days off and do all the work myself..

Ok, put the tranny back into the car. Fluid level ok. New filters etc. Started, shifted to D. Had delays. It engaged after about 5 seconds or so. This did not make me happy obviously.

So took it for drive, very gentle on throttle. up to 70kmh, 3rd gear shifted ok. After that, bang....again p0733..again same problems.

Came back to yard. Disconnected main harness to solenoid valves...feels like in 1st...

question 1.

Can I burn OD clutches with very gently drive, in total about 5-6miles??

question 2.

When I disconnected the harness, thus cut the power to main regulator valve, which regulates main pressure in valve body, the shift to D was instantaneous. Like it should. In other words, the engagement was instant. For some reason I thing the TCM does not regulate the pressure inside the transmission properly. This could explain why I slip clutches, as it does not have enough pressure to hold em together.

I think the problem is not the tranny any more. As I will keep re-building it and it will burn itself.

Any other suggestions?
Since you have no line pressure faults, I don't think low LP is your problem, but you (or your shop) can check it by getting a special tool (tee fitting) that allows you to plumb a mechanical pressure gauge into the line pressure circuit, while the LP sensor is still connected. That way you can verify that the sensor reading is accurate.

It is indeed possible to fry a clutch very quickly if it is slipping. Have you air checked the OD clutch passage to verify that there is not a big leak somewhere? And did you confirm that your OD clutch clearance is correct?
 

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I made a special tool for reading line pressure...and guess what..

I have only 50-60 psi when running. In D, Reverse etc. No wonder I burned clutches in the past.

The odd thing, when I unplug the harness from either the solenoid block or from the line pressure sensor, boom. I have full 130-140 psi. SO this tells me that my pump is ok.

For some reason TCM keeps duty cycle (PWM signal) down to 10-20% to line pressure regulator, and it regulates the pressure down to 50 psi or so.

Will investigate reason for that
 

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I made a special tool for reading line pressure...and guess what..

I have only 50-60 psi when running. In D, Reverse etc. No wonder I burned clutches in the past.

The odd thing, when I unplug the harness from either the solenoid block or from the line pressure sensor, boom. I have full 130-140 psi. SO this tells me that my pump is ok.

For some reason TCM keeps duty cycle (PWM signal) down to 10-20% to line pressure regulator, and it regulates the pressure down to 50 psi or so.

Will investigate reason for that
The TCM should adjust the line pressure until the LP sensor reading matches the Desired LP. And if it can't properly adjust the LP, then it should set a line pressure fault. So that tells me that your TCM "thinks" the line pressure is OK, which means most likely you have a bad LP sensor (that is reading like 120 psi when the actual LP is only 50-60 psi).

Have you compared the actual LP versus the sensor reading (simultaneously)? If they don't match (within a few psi) then either the sensor is bad, the sensor wiring is bad, or the TCM is not correctly translating the sensor voltage into a line pressure reading. My first bet would be a bad sensor.
 

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Hi folks

Transengineer, I believe this is your writing also, as it shows good in depth technical knowledge
https://www.turbodieselregister.com/threads/p0868-line-pressure-low-again.247490/

Well...the frustrating part is, I went thru allllllll offf this...will keep digging deeper.

The hose bursted the other day so I had to go get a high pressure version (it says 300 psi on it, and so far holds ok)

Did some more testing today. Some funny things are happening.

1. Had old sensor on it. No reaction at all, the manual gauge was showing something around 20 psi. So I tried to fool the TCM, by adding resistors from negative wire to signal (like SONNEX trans line booster does). No effect

2. Changed the sensor, last time machine shop technician claimed some extra 55$ (yes, in my area everything costs about 4,5 times more than is States...no wonder I order everything from ebay, but have to wait 10-15 days for it......) of charge, for changing sensor. This was questioned by me and it came out to be that he accidentally broke the sensor (believe it or not...) so he will pay for that...nonsence...Long story short, he said this is new sensor. So I put this "new" sensor on, no change again UNTIL...I put the resistors back in circuit, and vualla! Gauge started to read 118-120 psi. I almost was happy. Another funny thing was ABS, ESP lights were on for some reason. And actually pressure started to raise to that value when friend hit the brake pedal, to shift it to D.. WEIRD..

So I adjusted the resistors value so I have full 120-130 psi while in D.

Worked for some minutes. And then...back to original page ! Damn..

It was late so friends shop was getting closed. Will do some more voodoo-ing tomorrow..

Hope it is not the TCM... it did not put off any DTC so far.
 

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Another thing I need to test on other vehicle , if I get a chance to get hold off is...

Line pressure sensor is 3 wire connector. 1. Ground. 2. 5v reference voltage . 3 . Signal output

When the sensor is DISCONNECTED, both of 2 and 3 have 5v reference. When the sensor is CONNECTED, line pressure drops to 2.4v something. So basically the sensor shorts the 5v reference to ground based on sensors impediance. No wonder I have full pump pressure on tranny when the sensor is out.

I need someone with more in depth knowledge of the system than myself to have technical chat...
 

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Another thing I need to test on other vehicle , if I get a chance to get hold off is...

Line pressure sensor is 3 wire connector. 1. Ground. 2. 5v reference voltage . 3 . Signal output

When the sensor is DISCONNECTED, both of 2 and 3 have 5v reference. When the sensor is CONNECTED, line pressure drops to 2.4v something. So basically the sensor shorts the 5v reference to ground based on sensors impediance. No wonder I have full pump pressure on tranny when the sensor is out.

I need someone with more in depth knowledge of the system than myself to have technical chat...
I think you may be making things too complicated. You need to compare the sensor reading to the mechanical gauge reading, to see if the sensor reading (or, more accurately, the TCM conversion of the sensor voltage) matches the gauge reading. That is step 1.

If the sensor reading is accurate, then check whether the actual LP matches the Desired LP. Yes, the Desired LP (and therefore, the actual LP) WILL change when you step on the brake pedal or start to move the shift lever. The TCM will raise the LP in anticipation of an impending shift into Drive (or Reverse). And the Desired LP will vary as you drive, based on torque level.

Since (with sensor unplugged) you get full LP, I believe you are correct in looking for a sensor (or wiring, or TCM) issue. See if your scan tool will display not only the LP reading, but also the LP sensor voltage. If so, you can see if the TCM is correctly translating the voltage to a pressure reading. A voltage of about 0.25V should correspond to about 30 psi. A voltage of 4.75V should give about 275 psi (I think), or at least something in that range.
 

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Ive hooked up scope to pin #11 of TCM, which is LP control solenoid. The system is negative controlled PWM, i.e. it controls negative side of pulses. Please see the video Ive uploaded to youtube.

Ive changed the resistance on wires by adding 2 3 more resistors, and the LP did respond. Scope responded also. So did analog gauge.

So this tells me TCM is ok.

Ive also tested the LP sensor separately. Connected 5v reference. And an odd thing...even without pressure it shows 2.5 volts at the output...

My theory is , LP sensor went bad, and TCM had wrong info about pressure being too high inside tranny, and it cut the pressure by reducing PWM signal on LP control solenoid. Thus wearing friction plates. No wonder I always had frictions worn after I re-built tranny..As I never changed LP sensor, as I was unaware of its functionality. Actually I did have P0869, saying LP high....Technicians told me its inside transmission

Anyways. Trying to locate LP sensor. I have to order and wait 2 weeks some.

If someone can do same simple test, by hooking up negativ to right bottom pin, positive to left bottom pin, and multimeter positive to right top pin (multimeter negative goes to right bottom pin, with 5v reference power supply negative ) and tell me what is the output voltage Id appreciate it. By theory, it shoud be 0 or some 0.2v without any pressure.

Here are videos.
 
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