02 Dakota 42RE transmission

[MT-2500]

02 Dakota ext cab 3.9 engine 42RE transmission 2W 155K
Transmission was oerheating a mo ago.
Last week quit moving and grinding gear noise in reverse or forward.
Broken snap ring found in bottom of pan.
Replace transmissiom with a used 75K transmission out of a 03 Dakota.

Now when put in reverse cold it shuts engine down.
Not like a lock up engaugement just shuts engine down like key shut off.
When starting to warm up in reverse there is a jerking feeling like engine miss.

After it warms up everything is good .
No engine kill or anything else except a little hard 3-4 shift under light engine load.
No codes or bad sensor readings.

But a scanner read out when it does it cold scanner shows voltage drop from 12 to 0 volts to ASD relay and battery voltage and transmission power relay and ign switch and sowes switch in od switch.

I am checking for broken wires or voltage and ground lose but have not found any yet.

Thanks for any help or ideas or experiance.
MT-2500

[jpb53]

Have you tried unplugging the trans 8 way connector and seeing what it does? Also other suspect area is crank sensor and O2 wiring. Good Luck.

[MT-2500]

Originally Posted by jpb53

Have you tried unplugging the trans 8 way connector and seeing what it does? Also other suspect area is crank sensor and O2 wiring. Good Luck.

Thanks for the reply.

Yes on unpluging transmission wiring.

Makes no difference.

O2 sensor wires could be crossed on rear sensors.



Crank sensor not sure but engine only dyes in reverse.

I have caught the injector pulse going way high when it does it. 28-30.
Working on what would cause that.

Also I can hold gas pedal down and keep it from dying out.

Thanks

[jpb53]

If a crank sensor is left in place it can be bumped during a trans r&r Components expand and contract with heat and cold. The eng torques in opposite directions from drive to rev. Sometime you stare at the target toolong everything gets fuzzy.

[MT-2500]

Originally Posted by jpb53

If a crank sensor is left in place it can be bumped during a trans r&r Components expand and contract with heat and cold. The eng torques in opposite directions from drive to rev. Sometime you stare at the target toolong everything gets fuzzy.

Thanks for the info.
I did leave it in place changing transmission.
Tryed not to bump it but never know
I will do some checking on it and look into it.
Thanks.

[MT-2500]

Originally Posted by jpb53

If a crank sensor is left in place it can be bumped during a trans r&r Components expand and contract with heat and cold. The eng torques in opposite directions from drive to rev. Sometime you stare at the target toolong everything gets fuzzy.

Thanks again for the info and help.

Got back on it yesterday.
Crank sensor showing strange odd pattern on scanner and lab scope.
Replaced crank sesor and all is fixed.
Even rough 3-4 shift.
When I looked at old sensor I noticed the mounting bracket was bent forward some.
I tryed not to bump it but.
I bent it or it was bent before by a prier transmission replacement.
Lesson learned the hard knocks way.
Remove crankshaft sensor before replacing tramnsmission.
Thanks MT

[jpb53]

Glad you got it fixed.