Hello Dodge guys, gals,

Let me introduce my truck first and list all the recently added/updated/replaced parts,
So that you are completely up to date,...before giving advice/replying!

My truck is a 2nd Gen Cummins 5.9L 24Valve 6 cylinder
'02 Dodge Ram 2500 quad cab SLT 2x4 Laramie with about 115K on it.

Products added changed/replaced about a year ago:
-Ranch Hand Legend full bumper replacements front and rear
-6X Hella Rallye 4000 Metal series / 2XPensil Beam ligths, / 2XCornering Beam lights, / 2XFog Lights, / 2X Hella Micro FF Fog Lights (as additional backup lights),
-4 X 20" Rockstar wheels, wit 4 X Toyo 33x12.50R20 LT Open Country tires,
-K&N lifetime airfilter,
-LUCAS additives all around; transmission, engine, ect

Products added changed/replaced about 6 months ago:
-Replaced the OEM 1/4th fuel lines with 3/8th fuel lines
-Fuel Boss belt fed fuel pump / which provides a solid 18PSI pressure
-Blue Chip Special X injection pump
-FASS DDRP (backup pump, incase the fuel boss belt breaks in the middle of nowhere with pressure switch)
-FASS 2 Micron Fuel / Water Separator Combo
-EDGE Juice with Attitude CS used for MONITORING all the vitals of my engine only!

Most products were supposed to INCREASE fuel efficiency, however, the opposite is true.
My truck used to run 18-20MPG,....now its severely DECREASED and barely making 10MPG!!!

My trucks transmission is acting strange for the last few weeks, and it actually seems to get progressively worse.
But before going to a garage, I though it might not be a bad idea to ask for some advice here, before the garage tells me that i need a new tranny.
If my transmission does needs replacing, then thats my worst $$$$ nightmare!!!

Last maintanance;
-Engine and transmission oil change; about 1000 miles ago.
-2 micron Fuel / water separator set,...still have the original filters with about 1000 miles on them,....about 3 full and a quart fuel tank!

Anyway, with all the given info above, you pretty much now everything there is to know about my trucks current condition.

So back to the initial question:
I'll try to explain what my automatic tranny is doing;
At about 50-55 MPH @1300/1350RPM my transmission seems to have a serious problem shifting into the 4th gear.
Instead it's rpm's goes HI-LO/HI-LO/HI-LO/shifting 4th-3rd-4th-3rd-4th-3rd-4th gear ect, ect for about a minute or two before it finally shifts/graps 4th gear and stays into it.
Does all of this make ANY sense?

The EDGE Juice with Attitude CS unfortunately does NOT provide any answers, because in "diagnostic" mode there are only TWO choices to pick from i.e:
-Performance test
-And Records
But NO actual TRUE engine diagnostics on this brand NEW device!

Do you think that my transmission needs a different gear ratio because of the big 20"wheels/33"tires?
Worn out transmission gears?
Or something totally different?

My apologies for the whole book I wrote here.

Any advice will be greatly appreciated!

Regards NICE_N_EEEZ

 

Pretty common issue with the shifting, sounds like you need a new APPS. Have you tried the free method of resetting your APPS to see if it helps? Works for some people, though most end up needing a new APPS, but since it is free

Here is how.... Unhook the negative cables on both batteries and let the truck sit like that for 30 mins. Leave the door open or turn on the overhead light so that it will drain any juice stored in a capacitor.

Then hook your batteries back up and turn your key to the on position but don't crank the starter, turn it off and then back on again, and once more Off then On leaving it in the ON position. ( that is on and off leaving it On on the third try)

Now slowly push the fuel pedal all the way to the floor and then slowly let it all the way back up. Turn off the key. You have now reset your APPS and you may find it no longer hunts for 4th gear.

 

if your from the north and drive on roads that have been salted, check you 7 way RV light socket, the first time my 99 did that it had green stuff living inside the back side where the wires hood to the socket, apparently the voltage was jumping around from the 12 post to the brake light, when the brakes come on, the OD goes off. it did it randomly at any speed above 45, not 50 55 like yours.
try this too, pull up on the brake pedal with your foot, that switch may need adjusting. brakes on, OD off.

clean the battery cables spotless also, be sure the cables are clamping the post tight.

 

My tranny did the same thing and it was my torque converter locking and unlocking. Cleaning (disconnecting and sanding) ALL the batter cables both hot and grounds helped for a while but it usually came back after 6 months. A DTT noise filter fixed it. It was $20-30 several years ago. I replaced the APPS fixed and it did not fix the problem.

 

torque convertor lock up

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For the last few months I had My torque convertor going nutz right around 30 to 50mph. Lock and unlock. finnally the trans quit. I checked the codes in the odometer and got 1762. Govenor pressure sensor offset volts to low or to high.

I replaced the governor pressure sensor and govenor pressure solenoid. Both dealer items. I actually bought a new pan, gasket, filter the sensor and solenoid. These parts ran $340.

Now the trans shifts so nice and runs so smooth. Generally when you read about the lock and unlock of the torque convertor guys say it is a bad ground, bad battery or dirty battery connections!!!!!!!! All I did was replace the sensor and solonoid and it runs great. My battery connetions are clean and greased with dielectric grease.

This is the second time this truck needed these 2 parts. What causes them to fail?

 

My vote is the TC. It's the same problem I had, between 45 and 55 it would surge pretty badly. If I shut off the OD it would still surge at about 30mph. I think it was tied closer to rpm than mph.
claened all the electrical twice and both worked for a while but the last fix was to by a filter for the ECU. It's been behaving really well since then. The dodge tech in my Jeep club believes it to be the alternator going, making "dirty" power that is throwing off the ECU's lock up signal.
$25 I could afford then the ~$125 for a new alternator will have to wait.

 

I'm having the same problems as of last week, the tranny doesn't know what gear to choose at about 50mph. I'm going to start with the cheapest possible fixes and work my way up. Who can tell me what an APPS is?? Thanks for any info.

 

APPS = Accelerator Pedal Position Sensor
Same as a TPS (Throttle Position Sensor) in a gasser.
This is where you accelerator cable interfaces with the engine. On my truck (and I believe almost all of our trucks) it is on the top, front of the block, just over the VP.

 

Check and clean all your ground wires b4 you go buy any thing do a search for SEARCHING TRANS....