Archived 47re not downshifting to first

[tgrfan2]

My 98 12V has 190K on the stock original transmission. I checked the line pressure last week in preparation for a service. It was 70psi. Occasionally it has failed to drop into first gear at a stop light, but would downshift manually OK. Today it did this multiple times with my wife. It still downshifted manually, but she said it slipped several times on the 1-2 upshift. Is this the solenoid going bad? What is the max pressure I can safely up line pressure to without seal damage. I have already decided on a DTT upgrade but hope to wait till tax time.

 

[JoeBioDiesel]

If the Throttle Valve calbe is mis-adjusted, disconnected or broken it will result in low line pressure and prevent a 2-1 downshift when stopped. Mine broke on my '96 and it did the same thing. Check the cable. If it's OK adjust it out a couple of clicks... 2 or 3.

Hope that helps.

Joe

 

[tgrfan2]

Thanks I will check that in the morning. I am going to fry a turkey and work on my truck at the same time. Hope I don't screw either up!

 

[tgrfan2]

I checked all that and seems OK. I happened on a check for the governor pressure solenoid and transducer at the ATS site. I have governor pressure at a stop in drive which indicates a bad solenoid. Hope the dealer has one in stock.

 

[Tom W]

I suggest you replace both sensor and solenoid. About $200 dealer only.

 

[tgrfan2]

I checked the governor port for pressure today. I found I had pressure there with truck in drive. According to diagnosis on another transmission forum this should mean the solenoid is bad. It also said if you check the pressure and there was none the transducer was bad. While I was checking and shifting back and forth the pressure dropped to zero one time and the Trans shifted normally into 1st. I replaced the solenoid but the transmission still fails to downshift. I hope the dealer will have the transducer in tomorrow.

 

[tgrfan2]

A couple of more questions. Does the transducer just pull out of the socket? Also after replacing the solenoid I road tested again. The truck will start out in 3rd gear if you start in drive. If you downshift to low then it actually downshifts to second. If you kick it in neutral and then back to low it will downshift to 1st whether you are rolling or standing still. Reverse, drive and OD seem fine and it will automatically downshift to second as it always has. I hate to drop the pan again if the transducer cannot be the problem. Any ideas or should I call Bill K. I was hoping to keep it running stock a few more weeks.

 

[Missouri Mule]

This is from the service manual. I believe this is the symptom you are describing.

"No low gear(moves in 2nd or third gear only). 1. Governor valve sticking. 2. Governor circuit (re only) electical fault. 3. Valve body malfunction. 4. Front servo pistion cocked in bore. 5. Front band linkage malfunction.



Calling DTT is good idea too.

 

[tgrfan2]

Thanks for the info. I hauled it to my transmission man today. First time this morning it went into low when I shifted to drive. The rest of the time it would be in 3rd when I put it in drive and go to second when I downshifted from drive to low. The only way to get it into low then was to shift to neutral and back to low. Unfortunately after a few times doing that yesterday it would not shift out of low to anything but reverse. I guess that is "limp" mode. No check engine light though. Hopefully my transmission man will either build it per DTT specs or install one from them. Otherwise I have a 5 hour haul to Tenn or NC in my future.

 

[Tinman]

That sounds like when my went into limp mode last year. 3rd and 4th only. Not good at all to drive it like that. I replaced the trasducer and solenoid and that solved the problem. Easy fix. They both just pop right out. This was less that one year after a full DTT but it wasn't their fault, Chrysler electronics. (Believe it or not, I got both parts warrentied, so now I have spares) Funny thing is, with the DTT valve body, if the trans is in limp mode and you manually go to first, it completely locks up the rear end.

 

[Gritty12v]

Thanks for the info. I hauled it to my transmission man today. First time this morning it went into low when I shifted to drive. The rest of the time it would be in 3rd when I put it in drive and go to second when I downshifted from drive to low. The only way to get it into low then was to shift to neutral and back to low. Unfortunately after a few times doing that yesterday it would not shift out of low to anything but reverse. I guess that is "limp" mode. No check engine light though. Hopefully my transmission man will either build it per DTT specs or install one from them. Otherwise I have a 5 hour haul to Tenn or NC in my future.

Who is DTT

 

[Gritty12v]

Who is DTT? I have a 47 rh that won't downshift right. Almost always first gear