We have a 93 Caravan and every once in a while it will act like the transmission is slipping. We wil be driving along at 50 and the van will jump and the speedometer will go down to zero and then straighten back out. This happens with no regularity. It may happen 3 times one day and then not happen for 3-4 days. Someone suggested that we may have a clogged filter, or that it may be a module. Any ideas would be helpful.

Mike

 

Unfortunately it sounds more to me like a computer failure.The speedometer shouldn't go to zero just because the tranny is slipping.It could be a sensor failing or a loose connection in the wiring harness also.Have any trouble codes read and repost.

 

There is a transmission solenoid pack and another control module that can be replaced externally without dropping the tranny. sound smore like your speed solenoid pack is the problem since it's speedo related. worth a shot since if you get a rebuild you can reuse it.
100,000 miles is the life span of these trannies. I got 99,000 out of the 1st one, 104, 000 on the 2nd and now I am on my 3rd.

 

Try replacing the speed sensor, sometime when the speedo reads 50 mph the sensor maybe at 140 mph and cutting the fuel off.