Engine/Transmission (1994 - 1998) lock up problems

[RVPILOT]

I am having problems with getting lock up. auto trans rebuilt with all new stuff inside, intermittent lock up before rebuild and same after replaced t p s, no difference. went to Dodge dealer checked out with scan , no codes.

conclusion, was installed wrong. O K ? . locked for 150 miles and stopped

locking up. replaced speed sensor, no differene. replaced stop light switch, no difference. now here is the strangest thing of all, travelling down the road

and trying to keep the speed limit down I step on the brake with W O T and it goes into lockup and goes out again as soon as lift off of throttle.

acellerating up to about 40 M P H+ with 3/4 throttle it goes into lock up only to come out in about 4 seconds with steady throttle. any soulitions ? stormy

 

[Missouri Mule]

Contact DTT they should know what is wrong.

 

[RVPILOT]

lockup

Called D T T, they have no answers. not mentioned is that it locks up only on acellerating partial or w o t and goes out of lockup after 3 or 4 sec.

I will be looking into engine speed sensor next. stormy

 

[cerberusiam]

47RE or RH trans?



With the unlocking when you lift off the throttle, isn't that normal operation with those years of trucks? I thought that was typical operation.



Not holding the lockup sounds like the PCM is not recognizing the TPS signal for long enough, or, its getting interference that is causing it drop the lockup signal. You may have the same problem as the later trucks with noise generated by the alternator causing issues.



You might want to try removing the charge wire and passenger battery ground wire from proximity to the TPS harness if it is close. Not sure on that year how the harness is constructed but its worth a look.

 

[RVPILOT]

lockup

lifting off the throttle is one way to know if it's locked, the rpm does not drop. when it's unlocked the rpm goes down 4 or 500. stormy

 

[cerberusiam]

lifting off the throttle is one way to know if it's locked, the rpm does not drop. when it's unlocked the rpm goes down 4 or 500. stormy

I understand that. The question is whether that is normal operation. A lot of these earlier controllers unlocked the TC when the TPS readings went to zero or took a large percentage drop.



What did it do in the same situation new is the question? Does it unlock when you lift a little bit? a moderate bit? a whole lot?



Since one of the main controls for lockup is the TPS reading that would be my first consideration in what the signal is doing.



Again, RH or RE transmission? There are other electronic controls that can influence things with the RE.

 

[budnate]

sounds like possible noise in the wiring or you initial voltage on the TPS is to low... you need to hog out the mounting holes and rotate it and get up around 1V,,,play with it some like . 9v some like 1. 2V intial... . when you roll into the throttle it increases the voltage output at the tps and is locking it up... light pedal and it unlocks... sounds like tps to me... no for sure's chasing these trannie issues takes trial and error driving around and adjusting things to find the sweet spot with your truck... . I would go after the tps initial voltage from what your describing and what you have done... . do a search there is good reads on setting initial TPS voltage at idle.



peace, B.

 

[RVPILOT]

lockup

routed out holes on T P S and it now locks up, how long it will last I will find out. thanks budnate. I have done this before and it seems that I am chasing the throttle actuating cam for the T P S. first it was removing the bolt sleeves and it worked then stopped, the routed out the holes and worked then stopped. routed out again and now working. stormy

 

[budnate]

I am in the same boat... if I took a picture of my hogged out holes it would blow your mind, I am almost so far its about to come out the corner of the tps...



just a FYI if your really into eliminating slop I found the blade/driver from the throttle that drives the TPS was really sloppy going into the tps,,,I bent over a small piece of alum over the blade and installed the tps over it, took all the slop out so its a positive stroke both ways with the throttle, that helped smooth operation out a bunch... that will buy you more adjustment with the tps voltage as well...



I started out with about . 975V worked for a month then dropping out, then I went to about 1. 2V if I recall right, worked for a year then started dropping out again... I am up to about 1. 4V initial on my truck now, also installed a NAPA alt thinking my old unit may be throwing garbage voltage at the same time... it's been 8 months.



and now the muther F%$#@! is starting to do it once in awhile unlocking and also for some reason it's throwing the Gov. press codes and over 3psi at idle codes and going into limp mode when sitting at a light in gear...



driving around with the DB2 in the truck and have reset codes 3 times in a month... . good thing I love this truck so much or I would light it on fire for all the hassles it has given me, LOL. when I calm down I am going back in and taking some pressure readings off the case and deciding my next move, trans is solid hits the gears clean and dont slip... I hate to yank it apart just because... its a fricken control headache at this point i think... but maybe a converter issue with the locking being random.



been a long week it's miller time, peace, B.

 

[Missouri Mule]

Should be 47re that's the 96 Service manual has in it.

 

[LandShark]

Install a mystery switch.

 

[budnate]

Install a mystery switch.

I am getting close to doing it and giving up... being stubborn, really trying to make it work like it's supposed to.



wife allready calls it a pos, have to give it a tad of pedal when cold, run the trans in neutral while it warms up and fills the converter... if I threw in hey babe this switch is for when your... ... :-{}



B.

 

[RVPILOT]

lockup

Talked to the transmission man the other day and he suggested a mystery switch and wire it thru a pressure switch using a port on the transmission. The press sw will engage in 3rd and O D and disconnect when press is lower. any ideas about this arrangement?

The T P S thats in now is the old one. I think there is a possibility that the lingkage is worn as it was replaced at about 175,000 miles with factory recall. will check it out. stormy

 

[LandShark]

A lockup (mystery) switch will help determine where the problem is. It will lock the TC in 3rd or 4th and keep it locked to to point of stalling the engine if not turned off. It may help make the truck more drivable until you figure our where the real problem lies.

Truck is designed such that the TC will unlock when the brake pedal is pushed or when the throttle comes all the way up. This does not apply when using the mystery switch.

The TC should fill up within about 10 seconds when cold. If it doesn't, I would suspect the quality of the trans rebuild. If the drain back valve is still in the cooling line you should never have to wait (unless the truck has been sitting for weeks).

 

[cerberusiam]

The press sw will engage in 3rd and O D and disconnect when press is lower.

There is no good way to make this happen and NOT interfere with driveability. Since both lockup and OD are computer controlled there is no trigger point for pressure to engage correctly. No matter how its wired there is still a manual step in there or you loose some important functionality. Bottom line is you still need a valid TPS signal to function correctly. Still don't know if you have an RE or RH so its impossible to evluate anything like that.



Depends on what you want to deal with as far as application. If other people drive the truck then its just a bad idea.