1997 B1500/46RE trouble shooting help, please.

[lordgotmilk]

I've been working on fixing our family van. The transmission (46RE with lock up converter) is acting up. If you put it in D, you feel the kick like it's going into 1st, but when you give it a little gas, it just sits there. You can put the gear selector into 1st and it will lock in and go, then shift to 2nd and it will shift, then into D and it will go into 3rd gear. I don't have a place to get it going fast enough to know if it will go in to overdrive. I turn it around at a park about a mile down the road and it appears to loose gear while in D and will just sit there. If I shift down to 1st, it will lock in and the only difference from driving down there is that when I shift to 2nd and D, the engine races before locking into gear and sometimes on the return trip it will slip some in 3rd.

The only code it has thrown is P0740 Torque Converter Circuit. I described the code and what it's doing to a tech in a local dealer and he said it's either the Governor pressure sensor or the transducer, so I bought both and changed them. It's still doing the exact same thing and need to narrow this down since the cost of those parts eliminated about half of what I have on hand to get this fixed (moneywise). This is the only transportation for my family of 8 and is the main transportation for my wife and our oldest to get to college. They've already missed their first week of the quarter and I need to get this back on the road.

Thanks for any help you can give in narrowing down the likely culprit.

[mikie1]

Sounds like an overunning clutch.
When shifted manually the overrunning clutch is not used.
But when you just put it in drive it is.
You might as well count on a rebuild.
The gov and solinoid usually gives a code and indication it is bad is the shift points will be higher than normal , or not drive at all.

[B-300]

Wrong... If the overunning clutch fails the transmission will only work with gear selector in the 1st and Rev positions.
Have you checked the fluid level?
It could be giving an error code on the torque convertor since it is slipping... When the convertor is locked up the ECU can measure engine RPM and Vehicle speed and tell if there is slippage occuring.

[lordgotmilk]

Sorry it took a bit to respond....work does that.

As far as it goes, when I start it up it will only lock into gear and go with the gear selector in reverse and 1st, though I can manually shift it into other gears once moving until it warms up then it will still work to get it going but it will slip before locking into 2nd and with 3rd it slips.

As to the issue with the code it threw, when I did the transducer and sensor change I cleared the code and I haven't gotten it to the speed that I've been told would likely throw the code again (roughly the speed that it would shift to overdrive). The P0740 code is Torque Converter Circuit Malfunction, which made sense to me that it would have to do with one of the electrical parts, but automatic transmissions are completely new to me when it comes to working on them. Even the shop I worked at sent transmission problems to a local transmission specialist.

Oh and fluid level is good. I checked it a few times with it running and warmed up.

[B-300]

The P0740 code says the engine RPM is to high for the Vehicle speed. (Most are listed in the engine sub-section)
When the transmission is in 3rd it will lockup the convertor at about 30mph and set a code if it slips.
It sounds like rebuild time due to slippage.

[lordgotmilk]

Well, finally had the time this morning to talk to the specialist at the dealership. He told me that about 90% of the 46RE's they get in that are throwing a P0740 code are fixed by replacing the transducer and governor pressure sensor. Since those didn't work, he said that it needs a complete rebuild. Now to determine if we can find a way for the two college students to get to school or if they'll have to drop out. At the moment it's looking like the latter.