OregonRS

I'm looking at buying a 2004 Venture Cargo with 200k miles. I'm told that the transmission was rebuilt at 130k.

I test drove it today paying special attention to how the transmission shifts as I have read about issues with that. I let it warm up to operating temperature. With moderate acceleration it "pauses" (decelerates?) slightly for 1.5 2 seconds, then shifts. The shift is more heavy of a "clunk" than I'd generally expect, but I have no experience with this type of vehicle. The behavior is consistent on upshifting between any gears.

The trans oil was very slightly low but also very clean. I scanned for OBDII codes and only found a pending one about the EVAP system. I cleared it and drove the car about 12 miles and scanned again. No new codes were found.

Is this normal or is it a sign of impending transmission problems?

I've read about problems with the Transmission Pressure Solenoid, but it appears that generally throws a code (P1811) and I'm not seeing any. (Added note: I learned that my scanner likely won't read codes from the TCU, so this may not be relevant.)

If it does turn out to be the Solenoid, can it be replaced from below or does the transmission have to be removed?

Thanks to all for any input on this.

OregonRS

Follow up.....

Spoke with a fellow at a local transmission shop who was very knowledgeable about this particular transmission. It sounds as if it is in "transmission limp mode". I'll have him scan it on Tuesday to see what is causing it.

He indicated that he can read the fluid pressure that is reached on each shift. If one particular gear shows high pressure, that indicates that particular clutch system as having a problem. If it is all of them, it may be a common element such as a pressure sensor or solenoid.

Photon440

It doesn't really sound as though you are in 'limp in mode', in that case you likely wouldn't have any shifting problems at all; the transmission would start and stay in second gear only.

OregonRS

Thank you for the info. I had the mechanic scan it and his diagnosis (it was over the phone from my description) was not correct. There were no transmission codes and there was still about 10psi left on the worst clutch. It sounds as if the shifting is normal under heavy acceleration and I'm just not familiar with it.