Hi, My 2009 uplander lt ext has about 155 000 kms on it.
I have noticed that between 60-100 km/hr ,under light acceleration or going uphill, that the transmission seems to try to shift down/up but cant make up its mind, resulting in a jerking feeling until you press the gas pedal harder.

What could be the cause of this? there are no lights on the dash, but could there still be codes get from the computer?

Could it be a solenoid?
My 2000 venture had a similar problem around 90 000 km, got the solenoid replaced under warranty, but the sub frame had to dropped and stuff to do the job, I am hoping its a bit easier to replace on the uplander?

Alex

 

It could be the solenoid, or a few other things. The bad news is I believe if it is the solenoid the procedure will be the same as for the Venture.

Has the trans fluid and filter ever been replaced?

 

What else do you think it could be?

Transmission fluid and filter was replaced when the van had around 80000 - 90000km.

 

Some things will set codes and not trigger the CEL (I believe).

I wonder if you got some bad gas ?? .....

Have you changed the spark plugs in the van?

Perhaps tech2 will read this thread and render an opinion .

 

You described it as hunting for a gear so:
1. Fluid (low or burnt)
2. Solenoid
3. Valve body
4. Torque converter
5. Locking clutch

Looks like you've got 65-75000 km on the new fluid so far...might be a good time to check it out.

 

Sometimes the rubber seals benefit from softening additive. The lip seals can then get a grip with the hydraulic pressure. It is worth a try, It corrected my tcc from going in and out of lockup every few seconds.
You could see it on the tach.

 

It happened to me before..i call it shudding feeling when accelerates...i just replace the transmission oil and filter then flush it...It worked for me, From then on i never experienced the shudding effect. Hope this helps.

 

Hi everyone, I haven't had the jerking/shuddering since my original post, so I'm going to agree with Papabear and assume it was bad gas I bought. I had actually planned to do plugs and wires, along with a transmission oil change this summer.
Thanks for everyone's help