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Discussion Starter · #1 ·
Hello, I am new to the forum and not sure this is the place to post a transmission question, so if there is a better place feel free to shoot me...

I just purchased a 3500 Dodge Dually and it has an automatic transmission. The first day of driving it has caused me concern. As I get up to speed for it to go into overdrive, it locks and then almost instantly unlocks, then locks back up to stay after a few seconds. It does not come back out after the second lockup. When it unlocks, it feels almost like it is in neutral for those few seconds. The engine sounds like there is no load. I wonder if 4th gear is gone or something.

I have also noticed on a cold start that the truck doesn't want to move when I first put it in gear. After going back to neutral and back into drive it will go. Hopefully these questions will get to someone who has automatic transmission experience, as these things may not be uniusual for diesels.

Thanks in advance to anyone who can help...

Galen
 

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could be a bad tps. make sure BOTH your batterys are matched and in good shape. some times dirty alternator output will mess with the tps siganl. if you have the early trans with the mech. governor you can ground the return wire at the trans to see if the problem is in the trans or outside the trans. and what its doing is the lockup torque converter is locking and unlocking. its not the overdrive.
 
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Ok, second problem first. The "no go" first thing in the morning is a characteristic from the original TorqueFlites. These transmissions were originally designed to be started in neutral. This is because fluid doesn't get pumped in "park." If you start it in neutral, there won't be any problem with the "no go." There are kits available to modify the VB to make the trans pump fluid in Park, and other kits to keep the TC from "draining back" into the pan.

Now the first problem. I'm not sure how fast the "lock, unlock, shift, lock" happens, but the neutral feel is likely the trans shifting to fourth gear. There are those who will argue this, but the fact is, these transmissions will lock up in 3rd gear even when OD is selected. So the sequence you feel is possibly the trans doing its normal shift sequence.

If its not, and you determine that the 3-4 shift isn't happening during the sequence you describe, its possible that the APPS needs to be reset. It may be the TC lock up signal being "interefered with" by the alternator wire that runs parallel to it. Before you spend money on "repairs", live with the problem for a few days, or a week, and see if the truck is actually operating normally. Keep in mind, the PCM on this truck is complex enough to "learn" your driving style and tailor itself to the conditions it sees most often. It may simply be learning how you drive.
 

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I had found that starting my 97 in neutral for the 1st time in the morning and that eliminated the neutral feeling. On the 3 to 4 shift problem I had the same problem and replacing the TPS did not help also replacing the TC lock up solinoid did not help either found that the wire from thr CPU would pick up different pulse and was causing the problem, I found a kit on line that cured the problem.
 

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Discussion Starter · #5 ·
Thank you

Ok, second problem first. The "no go" first thing in the morning is a characteristic from the original TorqueFlites. These transmissions were originally designed to be started in neutral. This is because fluid doesn't get pumped in "park." If you start it in neutral, there won't be any problem with the "no go." There are kits available to modify the VB to make the trans pump fluid in Park, and other kits to keep the TC from "draining back" into the pan.

Now the first problem. I'm not sure how fast the "lock, unlock, shift, lock" happens, but the neutral feel is likely the trans shifting to fourth gear. There are those who will argue this, but the fact is, these transmissions will lock up in 3rd gear even when OD is selected. So the sequence you feel is possibly the trans doing its normal shift sequence.

If its not, and you determine that the 3-4 shift isn't happening during the sequence you describe, its possible that the APPS needs to be reset. It may be the TC lock up signal being "interefered with" by the alternator wire that runs parallel to it. Before you spend money on "repairs", live with the problem for a few days, or a week, and see if the truck is actually operating normally. Keep in mind, the PCM on this truck is complex enough to "learn" your driving style and tailor itself to the conditions it sees most often. It may simply be learning how you drive.
So relieved to have the answer to the "no go" problem. I did drive the truck last night and the torque convertor locked once driving out of the driveway! It then did not do the "double lock" when I got up to speed. I will take your advice and just drive it for a while. I do intend to change the fluid and filter right away. It is nice and red and doesn't smell too bad, but I don't have records for when it was changed last.

How do I reset the APPS?
 

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Discussion Starter · #6 ·
Thanks Farmer Boy

I had found that starting my 97 in neutral for the 1st time in the morning and that eliminated the neutral feeling. On the 3 to 4 shift problem I had the same problem and replacing the TPS did not help also replacing the TC lock up solinoid did not help either found that the wire from thr CPU would pick up different pulse and was causing the problem, I found a kit on line that cured the problem.
Thank you for your response. What is the kit called? I drove it last night and it didn't do the "double lockup" but it locked once going out of my driveway! I think the interference noise option is quite likely...
 

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I am new to this truck and I am trying to figure out a few things

please tell me about this cpu wire interference kit??????

My scanner shows the tps low at .2 and reads up to 3.87 high. also seemd to read the pedal % right. But I have the late 3-4 shift. It just seems to hold the shift way to long.

Please also tell me what the 3k-4k mod is for

Thanks
Jesse

1997 Ram 3500 Diesel Automatic 2x4
 
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