Generic automotive question concerning a 1992 Grand Caravan 4-speed

I'd get one of those contraptions that sucks the ATF out of the dipstick tube, replace whatever you sucked out, then pull the transmission coolant lines and flush it that way.

Take it in and have the pros do a tranny flush. Not that costly and should improve shifting. With my 94 grand, the fluid was dark colored and overdue for replacement.

I know on later vehicles, when the fluid is changed, you need to reset the TCM back to its defaults so it can relearn to adjust things to the new properties - I assume that also applies to 92's (could be wrong).

But you replaced about half the fluid. Anything you do will be a dilution process, so you'll never get 100%, but you can certainly do better than 1/2. A second pan drop will probably get you in the 80% range. You could disconnect the cooler return line and let it run into a waste bucket while you put in at approximately the same rate as it comes out - that has the advantage of also swapping fluid in the torque converter. That will probably put the new fluid at 95+% if you were to run, say 12 or 14 quarts of new fluid into it. Probably more mess than you want to mess with though from the sounds of it. If you have more money than desire to do it thoroughly, then pay a dealer to do it - but make sure they tell you what you will get for your money - i.e., that they aren't just going to do another pan drop.

Chrysler's TSB, issued back when those 4-speeds still had dipsticks labelled "DEXRON", told dealers to drain and fill 3 times with ATF+ to remove enough of the Dexron "contamination".

Well, I am not sure what's in the trans. I know the original owner had it service at a Chrysler dealer, and I would assume they know what's what.

The last owner had it four years, and he seems to know a bit about cars, so I'm hoping he knew to use ATF+3 or +4. I'm not having any real problems with the tranny except a small amount of bump-shift at lower speeds. The van has 239,000 on it so some bumps and groans are to be expected.

Unfortunately (er, perhaps, fortunately?) the only bottle in the van was brake fluid, and we found the leak. No oil cans or trans fluid cans. I'm hoping that means there weren't any problems...but it doesn't give me a clue as to what fluids were put into the vehicle when needed...

Wow. He reference a real TSB! Thanks!

My LHS was filled with 'modified' Dexron, and started slipping in 20 miles. There isn't any slipping, so I'm hoping it has the right stuff in it. I'll go 1,000 miles, drain and fill and then do it again.

That's what I was thinking: do the Lazy Man's Flush and pull the pressure line off the cooler with the trans in N and fill the thing while it's running.

We're bringing it into my friend's shop later this week to replace the brake lines, and I might try this. Or just do another drain and fill...

If you have a nice warm shop, then I would definitely do the transmission cooler flush method instead of a 3rd flush in mid-winter.

I would be interested to know if it is the original transmission. I bought a new 1993 Grand Voyager in Nov. 1992. The transmission problems were already starting to become well known by then. I tried to keep the fluid fresh, hoping to avoid the problems that others had seen. I always made sure that ATF3+ 7176 was always used.

In July 2007, the transmission died at 95,000 miles. I had a local shop rebuild it. They rebuilt it, and brought it up to 1998 specs, along with a "flashable" transmission contol module. The early ones like mine were not flashable. If the TCM does not have cooling fins, it is not flashable.

After the rebuild, it still had some problems shifting. They had to re- crimp all the connectors in the harness, so fix that problem. That may have been what killed the transmission in the first place, I am just guessing.

Anyway, it has been more than two years, and it is still running fine. The shop where I had the rebuild recommends changing the fluid once a year, which I think is more than necessary.

If your transmission and all related components is original, then it has lasted much longer than most.

KM

My research has shown soft materials used in pieces in the transmission.

To get this far, it had to be replaced at some point. They all failed.

These things are somewhat indestructable. They had the trans problem, and the 3.3 had some rocker tower failures, but if you get your hands on one that has these issues sorted out, then you can put it up against any Japanese car out there.

And I am a Japanese car fan! Google "Hachiroku"!

I used to work for a guy that did this to a couple of higher mileage Escorts we had for asle. He did two. He never did another one. One stopped moving after about 150 miles, and the other stopped on the way back from being flushed!!

Besides, if you talk to the guys that do it, they will tell you "We use a generic type of ATF and add the proper friction modifiers for the transmission it's being placed in."

Un-uh. Chrysler specifies AFT+, so ATF+ it gets!

If the brakes don't give us too hard a time Friday, maybe we'll do a "ppor man's flush", remove the incoming line from the cooler and add ATF+4 while running in neutral.