2002 Dodge R3500 - Trans Dropping Out - FIXED

[Tim Martin]

Transmission guys! Where are ya? I got this 02 R3500 with a 5.9L Diesel and an auto trans. The issue is that you can start the engine, start going down the road, trans works fine and after a few minutes, the trans seems to be in neutral. It may or may not go back in gear on its own. I did notice that with my scan tool connected, when the trans seems to be in neutral, there is no desired governer pressure nor is there actual governor pressure. If I have governor pressure then the trans comes into gear and away we go. There are no codes and I am wondering what to look for. The fluid is full, color and smell are fine.

[mopwrforme]

hello tim in talking to my co owner which has been building chrysler trans. for about 40yrs. basicly tells me that gov. presure will effect shift points and loss of gov. preasure shouldnt effect gear engagement that would be line preasure. in haveing some problems with the wireing to the gov. preasure selonoid it can cause all kinds of problems but shouldnt act like its in n it just wont shift rule of thumb if the vehical is moving you would have gov. preasure apx. 1lds per mile an hr. of speed ck line preasure when it acts up also make sure the manual valve is adjusted correctly with the scan tool see if it goes into n on the scanner when it acts up. also there was a big issue with the tq on that model truck which would in turn clog up the filter with tq matter ie no line preasure. my trans guy is not in house this week but i will try and be a relay for any questions if i can. tim be carefull ive been burnt my share on dodge diesels with the engine having drive issues that i could have bet the farm was trans related.

[Tim Martin]

Hey thanks for the reply. What is really strange is that it is not consistent. What I mean is that one time I can drive the truck for a number of miles without a problem. Next time I can get a mile down the road and it acts up. Nothing consistent whatsoever. To me it sounds like an electrical issue of some proportion. But I am not as familiar with transmissions as I should be. Changed the filter and fluid less than 1,000 miles ago. Also we do have new governor pressure and governor solenoid installed with no change. So it appears like an issue before them. Can a TPS that is glitching out cause this? Or should I drop the pan and look for loose connection, or wiring rubbing through or the likes?

[mopwrforme]

it sounds like your on the right path with the wireing issue ive found on the firewall drivers side wireing harrness theres a large multi pin connecter that goes to the trans, ck. it for moisture or green stuff. to answer your question on the tps yes it can the trans controller needs to see wheel speed signal, tps for load and map all are part of the equation for gov. preasure with a drb3 i can see calculated tps in a perfect world it will match the tps., this sounds like a challange but honestly ive seen everything from wireing to an internal trans issue such as tq,line preasure bad trans case connecters pinched wireing between the case and block good luck ill ck back later i hope ive been some help

[wbuxton]

VSS will cause it to stay in first. If it drops out after shifting normally.

[Tim Martin]

After going over all the wiring to the transmission and installing a used TPS for diag purposes, I finally dropped the pan for a peek. What I saw was a filter that was totally plugged with black mush, so to speak. I installed a new filter and went for a drive. It worked fine. Customer picked the truck up later in the day and has been working fine since. What was happening was that the system was starving for oil. Have not seen anything quite like that before.

[steven kiser]

i'm wondering if a wonder additive was added.

[Tim Martin]

i'm wondering if a wonder additive was added.

You mean added by the customer or by me?

[steven kiser]

customer. didn't mean to imply anything but. on answers i make along these lines the thought of magic fluids or witch dr remidies never cross my mind because of the quality of craftsmanship of the forum members. however if someone comes into my shop with an issue and during my question and answer session i learn that it's been at other shops with this issue that becomes my prime focus. i know that there is a good chance the gas tank may be loaded with chemicals, crank case full of motor medic, cooling system loaded with barz leak. this is norman operating procedure. thinking that about you didn't even cross my mind. if i though like that i wouldn't bother replying to any of your posts or if i did would make my view about magic potions very clear. i apologize for the fact that i made you even have to ask the question.

[Tim Martin]

No offense to me steve. I appreciate when the person I am discussing an issue with is frank and I try to understand what they are saying. And when it is not clear to me what is being said, I ask. Having said that, the customer is threatening to add an oil additive from the Conklin Co. He is a dealer for that company. I am not knocking the company or its products but I tend to be somewhat suspicious about these "wonder" or "miracle" products. For myself, I absolutely do not promote nor endorse any of these products. I tell folks, my shop makes repairs after it is proven that these products did not do their job.

End of story.