Our 2002 Grand Caravan had the transmission replaced under warranty at 69,700 miles. It is now up to 126K miles.
There are no current problems with the transmission, but should I have the fluid replaced?
If so, what specific brand / type?
Is the transmission supposed to be "flushed"?

 

Use ATF+4 transmission fluid. I don't think too many shops actually "flush" the transmission anymore these days. Then you have to make sure if they used synthetic or regular ATF+4 transmission fluid as you shouldn't mix the two together. Have the transmission filter changed as well when you do this.

 

How can I tell, as it was added when the transmission was replaced by the dealer years ago?

 

A flush service is recommended as it’s the best way to replace as much fluid as possible, but it won’t replace all of it (nothing short of a rebuild will replace all the fluid). You can request a fluid and filter service only without the flush if you want. The shop can insist on a flush, and then you can find another shop if you don’t want it.

Whether or or not it needs to be done depends on 2 things:

1) Condition of the ATF
2) Recommended service interval

1) Condition - fluid should be red (bright red is ideal but dark red doesn’t necessarily mean it’s bad) when wiped from the dipstick onto a clean white paper towel. Brown or black fluid should be replaced. If it has a burnt smell it should be replaced regardless of color.

2) Service interval - Check your owner manual (or any paperwork that may have come with the replacement trans) for the recommended service interval, but for the sake of discussion let’s say it’s supposed to be 50,000 miles. Since it was replaced at 69,700 you can use that as the “zero” mileage starting point which means the next recommended service would be at 119,700.

Other factors to consider are how many miles are you putting on it each year, how long do you plan to keep it, how is it being driven (hard and fast acceleration vs. slow and steady) and so on.

As to what fluid to use, if you go to a dealer, they will put ATF+4 in it. What an independent shop will use depends on the shop - a couple of years ago, we just ordered the type of ATF as we needed it. Then we started using a full synthetic ATF that will work in every make/model except for CVT’s. It’s good stuff and it’s convenient to have on hand, but it’s also $9/quart.

 

Many thanks!

 

Oh ok. I guess some shops do it and some don't. When I was living outside Atlanta a few years ago, they wouldn't flush my aunts trans because they said it could free up some dirt and cause even more problems, as some customers brought their car back after a flush complaining of new transmission issues. We were told this by more than 1 shop. My guess is that they did something wrong, or the trans was about to fail anyway. So they said they stopped doing flushes.

 

Dirt and debris collect in the transmission oil cooler, and it’s not uncommon for it to get back into the transmission during a flush if it’s not done correctly, but it really comes down to the individual technician making the call.

A flush that’s done as part of routine maintenance helps keep that dirt and debris from building up, so there’s little reason to be concerned about it. But as with many things, people don’t worry about something until it’s acting up. Many transmissions don’t get a flush until the chance for basic maintenance has been passed by, and by then it’s got a lot of crud in the cooler. In those circumstances the cooler and transmission need to be flushed separately, or in some cases, the cooler and lines should just be replaced. Unfortunately some techs don’t pay attention to it or they’re just not experienced enough to know better and they end up pushing all that crap back into the transmission.

There are also some types of transmissions that shouldn’t be flushed because of how they operate, such as CVT’s.

 

there should be no problem with a complete fluid exchange on a new trans with only 50000miles on it. As long as your doing complete fluid exchanges at that interval...I wouldn't bother to change the depth filter.

If it was an old trans with worn clutch packs that never had a fluid change in its life...maybe a slight concern.