im new here and have a question about my recently purchased (about a week) 2000 ram 2500 5.9 quad cab 4x4 with 139,000 miles. while driving the "o/d off" light comes on by itself and stays on. i try hitting the switch on the shifter to try and turn it off, and that doesnt work. the only way i can get the light to turn off is to either park the truck (turn off the ignition) for a few minutes (5-10) or pull over somewhere and let the truck idle in park for about 5-10 minutes. all seems normal after that until it comes on again. everything shifts/drives fine even with the light on.

i took the truck back to the small dealer where i bought it and was told that it is common for the overdrive selonoid sticks in my model ram. i was also told by the place i bought my truck that the best cure is to buy some lucas transmission additive and add that into my transmission and drive my truck about 100 miles to unstick whatever is stuck. i did look at this additive i was told to buy and the bottle does claim it will unstick valves,ect in the trans. any thoughts??? will the additive work? has anyone heard of or had this problem? this is my 3rd ram and the first time i have run into this issue.

 

Is the Trans shifting out of OD when the light comes on? If it is then the trans temp is climbing up there and the trans is trying not to burn its self up. Check for flow through the cooler and check the check valve in the return line from the cooler. If you have good flow and the valve isn't stuck shut, get it in to a good trans shop before you start damaging hard parts.

 

i put the lucas in mine, at the same time time they did the tranny flush on it. seems to shift alot better, more positive and smoother in my opinion. i have 120,000 miles on mine and i tow my boat with it too.

 

i dont notice any kind shifting when it comes on. i did put in the lucas additive. it did seem to help some. before the additive i could drive about 15 miles before i see the light come on. now that i have added the lucas additive i can drive about 20 to 25 miles before the light comes on. although the other day, before i put in the additive, the o/d light came on followed shortly by the "trans temp" light and finally the "check engine" light. (my dashboard was looking like a christmas tree with all those lights on). i borrowed a OBD II scan tool from a buddy of mine and pulled a code "P1740" for the check engine light. i did get the following after a little internet reserch:


SYMPTOM
P1740 - TCC OR O/D SOLENOID PERFORMANCE

WHEN MONITORED
The Torque Converter Clutch (TCC) and Overdrive Clutch (O/D) will be tested each time the PCM requests TCC engagement in 3rd gear and O/D.

SET CONDITION
The code will set if the expected rpm drop is not achieved while attempting to engage TCC and/or O/D. This indicates a malfunctioning torque converter or overdrive clutch.


i also found this:

MIL ON - TCC/OD Solenoid Performance
Notes

NUMBER: 21-11-00

GROUP: Transmissions

EFFECTIVE DATE: October 02, 2000

SUBJECT:
46RE Transmission MIL Due To DTC P1740 - TCC or OD Solenoid Performance

OVERVIEW:
This bulletin involves the replacement of the transmission pressure boost valve cover plate.

MODELS:
2000 - 2001 (AB) Ram Van
2000 - 2001 (AN) Dakota
2000 - 2001 (BR/BE) Ram Truck
2000 - 2001 (DN) Durango

NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 46RE TRANSMISSION BUILT BEFORE AUGUST 01, 2000 (MDH O8O1XX).

SYMPTOM/CONDITION:
The customer may complain of a Malfunction Indicator Lamp (MIL) illumination. Upon further analysis, it is determined that the MIL is caused by Diagnostic Trouble Code (DTC) P1740 - Torque Converter Clutch (TCC) or Overdrive Solenoid Performance. Other than the MIL, the customer may not notice any other condition with the transmission.

This condition may be caused by an intermittent and momentary TCC disengagement condition. The transmission valve body pressure boost valve cover plate has been revised with a larger size orifice hole to address this condition.


i am not sure what all this means... it seems to apply to my problem, but i am not sure.

 

exactly where is this valve located? what does it look like?

i just got my truck back from the shop on friday night where the replaced the o/d solonoid. the light still came on.... also the check engine light came on again with the same trans code as before "p1740". is it possible that the new solonoid needs to "adjust itself" its been 2 days since the o/d light came on.... could it be fixed? the trans seems to shift a little better.

 

I hate to tell you Dodge guys this.....but putting a thickener like Lucas in your late model tranny is the absolute WORST thing you can do....I've lost count on how many people net wide have lost trannies that way. You can use seafoam as a pretreat BEFORE a filter change to remove guck and varnish, but not the other way around.

In the "good old days" thickeners or viscosity improvers had some merit as they increased pressures in older trannies. Unfortunatlly in todays modern world...thickeners can actually plug tiny passages and decrease flow. My advice....change the fluid, filter and adjust the bands.
The lining to "lockup" your tranny in OD is actually in the TC. When the factory linings wear thin, the lockup may not occur in the preset time, which after several run cycles, will trigger a code. Replacing the shift selenoid doesn't always help if the linings are worn and slipping. Eventually...you lose overdrive. Good aftermarket convertors actually use a thicker high temp lining to reduce wear and increase lifespan.

OMG..that check valve has gotta go....! That is the #1 destroyer of trannies....a great idea for fussy Mercedes owners who maintain thier cars religously. The valve looks like a large brass fitting on your tranny line just before the radiator tranny cooler.

 

I agree about the thickeners! If one must put in an addative try lubegard. Any other luck on the trans?

 

well its been one week and no lights have come on!!! maybe its fixed?

 

My dodge is doing the same thing. Please tell me what you did to fix this djk69. Thank you

 

If you read back it appears he:


1) Added Lucas additive (not recommended)
2) Had the OD solenoid replaced

However, he still got the light, but then reset it and after a week didn't get it again (at least for that week, he never reported back afterward).

I can tell you this, when this happened to mine it turned out to be a failing TC. Most shops will not just drop the tranny and bolt a new TC because the transmission could fail and then you will scream. So they recommend a new TC and full tranny rebuild.

I opted for a remanufactured tranasmission. Probably not what you wanted to hear because you don't want to drop 2 grand, but quick fixes aren't going to save the TC/trans. When it fails it will fail and the signs are pointing to that failure.