Alright, so I took the time and searched the forum for a340h auto diagnosis and found alot of valuable information. Before I go on, this is a 94 V6 truck, auto, 4x4.

Symptoms, feels like alot of slippage, slow shifts. Seems to hit neutral between shifts and then essentially slam into gear. Delayed shifts in both forward and reverse. When reversing up a hill, feels like its slipping.

I took my truck out today, manually shifted at every light and had much better results than leaving in drive. However, sometimes it seems like it gets stuck between gears or hits neutral when leaving a stop, other times smooth as butter. Tends to shift into overdrive way to early, about 35-40mph and drops the rpms way down, then no matter if you floor it, will not shift down unless manually shifted into "2", then I shift back into drive and it will stay in Drive (3rd) for a moment and then go back into overdrive, turning overdrive off (manual shifting) alleviates this problem.

If sitting at a light,while in drive, when the light turns green, it will act like its in neutral and then surge forward when it grabbs a gear. Checked engine and trans codes.. both "check engine" and "OD Off" lights flash constant, no patterns or codes.

Sorry for the long post, I would like to see if my existing trans is salvagable before spending the money for a replacement. Any advise or suggestions would be appreciated greatly. I am hoping its just a soleniod.

 

Let's start with the obvious - did you check the fluid (running while in park)? Have you had the fluid drained and refilled or flushed and filled lately?

Any other odd behavior from the truck?

I had similar symptoms when my speedo head went south.

 

Flushed completely about 3k ago, just drained and refilled before driving today.

Fluid level is right on when running in neutral.

 

Man do I feel for you. I have worse problems with mine. Cebby what do you think my tranny problem is?

 

Getting any bounce in the speedo needle?

Sounds like the flush dislodged some crap in the valve body. How many miles where on the old fluid?

 

funny i got some rpm needle bounce a couple days before this lockup problem with mine..when I let off the gas doing 65 on the highway

 

no needle bounce... about 30k on old fluid.

I drove it again tonight and left it in drive, it was shifting fine, just if i let off the gas, brake and come to a complete stop. When i go to take off again it will act like its in neutral and then jolt into gear... I guess it sort of delays shifting into first until I am rolling again. When at a complete stop, there is a noticable delay in the shift times from park, throughout all gears including reverse.

Still having the erradic shifting, sometimes it shifts fine, and when you apply moderate throttle it will drop a gear and go, sometimes, it will not shift down and about refuses to accelerate..

 

From the 93 FSM, page AT-67:

Problem:
Harsh engagement

Throttle cable out of adjustment or
Valve body or primary regulator faulty or
Accumulator pistons faulty or
Transmission faulty


Problem:
Slips on 1-2, 2-3, or 3-O/D up shift, or slips/shudders on acceleration

Manual linkage out of adjustment or
Throttle cable out of adjustment or
Valve body faulty or
Solenoid valve faulty or
Transmission faulty

 

Thanks for the info cebby...
There sure are alot of "or"s in that manual.. hmm.. where to start..

 

The fluid level should be checked in park, while at idle. Trans should be at operating temp, this means the trans fluid temp, not the engine temp. There should be two sets of min/max marks on the dip stick, one for cold and one for hot. If the fluid level is ok, then you might have a clogged screen in the trans, the symptoms shure sound like low fluid pressure.

 

I was thinking low fluid pressure, or something to that effect also, would explain the slow shifts and slipping.

However I took it to a transmission place a while back and the only explaination I received was, "complete rebuild about $3k". Yeah thanks a$$...

Yotatech rocks.. I am going to triple check my fluid levels and get reply back.

 

Considering your other posts, I am getting the feeling that you have been having some type of trans problem for a while now. I believe you mentioned a 'flush' 3k ago, and more recently a drain and refill. If you were noticing a problem and did the flush because of this, it may already be too late. Not that I am a member of the 'don't change fluid cause you will kill it' contingent, but if you were already having problems because of internal clutch wear a fluid change will not fix it. If the problems didn't appear until after the 'flush, then it is a possibliity that when the 'flush' was done, the wrong type of fluid was used and this is causing your problems.