Van shudders only from a stop

There are a couple things that make your van behave as it is behaving. In no particular order, it may be the torque converter is slipping a bit (doubtful, but possible). It could be the turbine slipping a bit (again doubtful, but possible). It may be the clutches that are slipping a bit (more likely, but again possible). Combined with the clutches, it could be the bands that are slipping (again more likely). It is possible that it could be the planetary gears themselves that are slipping a bit because there may be worn spots or a cog may be out of possible because it is slightly bent or nicked. It could also be that a solenoid pack is failing, but hasn’t quite gone yet.

You can see the many different possibilities that could be troubling your Venture. They are nice vans — I sold them for a bit so I am familiar with them — but like every other vehicle they do require maintenance.

You told me in your question that you have had all of the major service recommendations completed to which I say great. You are way ahed of lots of vehicle owners on that score, but, you told me something else that tripped an alarm in my mind — you haven’t changed the transmission fluid in some time.

Yes, I know that I could walk out to my sedan right now, pull the dipstick, rub the transmission fluid across my finger to see if it felt grittle and sniff it to see if it smelled burned. I don’t think that it would be, but, who knows? I could see if the levels looked right, as well. I also know they are probably right, as well.

With all of that said, though, you told me everything looks okay, but I have to tell you that it isn’t, if you haven’t replaced the transmission fluid in a while. Yes, the fluid has to be swapped out on the intervals outlined in your owner’s manual. If not, it starts to break down over time and begins to cause problems.

That’s exactly what I think is going on now. You see, premium transmission fluilds are vegetable-based, not solely petro-based. Because they are organic, the heat that they continually carry off begins to break them down over time. As they break down, their heat-carrying capacity falls, as well, as does their ability to protect the transmission.

The funny thing about the start of the breakdown is that if you pull the dipstick and look at the color of the fluid and sniff it, you won’t suspect anything is wrong because, at this point, it looks quite normal. But, trust me, it isn’t in good shape, if you have let it go beyond its safe point between 30,000 and 40,000 miles.

Here’s my suggestion: get the van to a good independent shop; have the transmission fluid drained out, not forgetting the quart or so in the pan (yes the lid has to be opened), closing things up and putting in a clean refill. I think this should fix the Venture right up. (While it’s open, if you have access to the transmission filter, I’d swap that as well.)