I have 1997 3.3i Voyager. Today the autobox started slipping, I was driving around town so was only at slow speed. 25mph or so and I would notice the car stop pulling and the revs climb. I would back off and the the gearbox would engage. Also, i'm not sure as I didn't get a change to drive quickly for long but I am not convinced it changed up, the revs seemed to high at 40mph.

Occasionally when very cold the box want go into gear from stationary, but it has never slipped when moving like today. It was a hot day (for the UK) but I can't imagine that got the transmission much hotter then it would after a drive.

Auto fluid levels look ok. It was hot when I checked and probably only 3 or 4 mm from the top dot on the stick.

Any comments on how terminal this could be? What are the odds a top up of trans fluid will fix it?

 

I have been looking at this stuff Lucas Transmission Fix normally I would be pretty skeptical and treat this like a radiator additive that would clog up all my pumps. But in this case If the only other choice is a ££££££ rebuild maybe an additive is a good idea?

 

Replacing the transmission fluid and a new filter is a good place to start. You MUST use the correct Chrysler ATF+4 fluid. If there's debris in the sump then you're probably out of luck.

Edit: Added fluid type.

 

VERY MUCH in TOTAL agreement with you! Drop the bottom trans pan, check for debris AND INSTALL a NEW TRANS. FILTER. Then refill the 4 quarts needed with ATF+4 trans oil(and no other type)!

 

Another bit of advice. If the pan has been off previously, then remove any gasket cement from inside of each of the bolt holes in the aluminium casing. If any gasket cement remains in the top of the holes you won't be able to tighten the bolts and risk stripping the threads in the casing. I learnt this the hard way and had to drill and tap some of the holes to use bigger bolts.

 

Thanks for the advice. The Trans oil was replaced around a year ago and looks really clean (hard to read the dipstick clean), but I can't be sure what the fluid type was. Sounds like I should change that asap for ATF+4.

Hopefully it will be ok, only started slipping a little two days ago and clonking a little when shifting from Park to Drive.

 

And be sure to fit a new filter. The old filter just pulls off the bottom of the transmission.

 

Both oil and filter have been ordered!

 

Ok I am mid fluid change and double checking fluid volumes and am a little confused.
It seems the service fill is 3.8L but the transmission holds 9.2L.
Autoboxes aren't my specialty. After googling I hadn't realised the torque converter holds so much oil. My concern is, if I have topped it up with the wrong fluid before, how easy/possible is it to drain the whole transmission for a full flush? Or does it matter as I start to dilute it down?

As a side note I took it up to speed, 60-70 mph and it wasn't changing up gear.

 

Well more Googling I flushed out more of the old fluid by disconnecting the cooler. I also added the Lucas stop slip. (In for a penny in for pound.) In total I have swapped out about 6.5L of fluid.

Hard to say if its better as the shift is still slippy, but I believe that is common after a fluid change.

My concern now is it isn't shifting up. I have read that this could be the Transmission Control Module (TCM) or TCM sensor. Or that the module has to retrain. Any thoughts? If it was a sensor/module would that always give an error code? I don't think my engine warning light is on.