proper 47re lockup operation

[Jay Cook]

hey everyone, just wanted to start out by saying how much this forum has helped me on this truck so far, long time chevy guy, this 98 2wd 3500 12 valve is my first dodge and first diesel and ive been spending the last 8 months or so trying to get everything in proper running order (older woman owned the truck for years and it was fairly neglected). that being said ive done alot of searching and am coming up somewhat stumped as to how lockup is supposed to work with this transmission. currently it appears my TPS is doing something because under super light throttle it will lock the converter in OD around 45mph. wide open throttle it will lock around 55mph. the question is, is this normal? i wouldnt think itd be good on the converter to lock under WOT. i was able to check TPS voltage in the idle position but being alone today i cant see what its doing above idle. TV cable has been tightened slightly, when i got the truck 1-2 shifted around 6mph regardless of throttle. now its between 8-13mph which seems ok. truck has 3.54 gears i believe, stock tire size, no modifications that i know of besides a straight 3" pipe in place of the muffler. hopefully this is posted in the correct location, first time actually posting on the forum.

 

[Joe Mc]

The "into" OD seems about right = 40-45 light throttle. Mine does the 1-2 shift at around 15mph, but that's based on start off throttle position, meaning: if I go to WOT from a stop it'll be higher 1-2 shift, if I'm creeping might go around 12mph. Do yourself a big favor and go to https://www.genosgarage.com/product/dfsm98-print/dodgeram-factory-service-manuals This will be the best $140 you'll spend on the truck.
Welcome to the TDR and to Cummins. NOTE: Go to the upper right hand of the site and hover over your name, select "Signature" and include some info about your truck. This way you don't have to say what it is each time you post or have other members have to ask "what is what".

 

[Ozymandias]

Yes, lock up under WOT is normal.

 

[Jay Cook]

Thanks for the reply’s. I was able to do a quick test this evening, got on a straight stretch of road at about 55mph (in od and lockup) and mashed the throttle about as far as I could and to my surprise it did drop out of lockup and I believe it actually dropped into third. So maybe I just wasn’t actually going to wide open as I’d originally thought, or perhaps my throttle linkage is slightly off.

 

[Ozymandias]

Yes at 55 it sure shifts back to 3th, around +/- 75 i is the point where it stays in 4th... and in Lock up.

 

[Jay Cook]

I noticed I still have the throttle linkage recall open for my truck so I may go ahead and have that done, that should ensure I’m getting full travel from in the cab when they set it up I’d think

 

[Timd32]

Does FCA still have to support the old recalls?

I know on my one GM gasser the TPS were junk and they had a 10yr limit. Basically they threw a couple at it for a while then it read like it would be on me, I got rid of it year 9.5 not because of the TPS so not sure if it.was a hard out as the paper read.

 

[Jay Cook]

i have a buddy thats in parts at a local chrysler dealer and he said the parts are still available under the recall number so im hoping for the best. its crude but i rigged a couple zipties between the pedal and the spring on the end of the cable, going to drive it a couple days and see if it feels any different, could explain my lack of power at wide open as well

 

[Jay Cook]

Little update, put a couple zip ties between the throttle pedal and the cable to see if it was a travel issue. Behaves about the same. I did notice that even at 50-55 or so if you roll into WOT it stays locked, if you go from 1/4 to WOT quickly it kicks down. If the pcm is smart enough I could see this being normal. I’m hoping it is, with the truck being stock id like to be able to put off either having an auto built or swapping to a manual as long as I can.

 

[Ozymandias]

You want to have it locked, believe me in this.
Thats how it should be, you want the torque to the wheels and not heat the transmission oil.

 

[Jay Cook]

as long as thats how its designed i plan on leaving it alone, fluid looks clean, doesnt smell burnt, i have to pull a car from kentucky to st louis in a few weeks so im just trying to give everything a good once over before i trust the old girl for the trip