Way Outta Control
Join Date: Sep 1999
Location: The Palouse
Thanked 3 Times in 3 Posts
Re: YJ - AutoTranny ID and What type of ATF?
So, IMHO (Disclamer: FWTW [img]images/icons/wink.gif[/img] ) I'd not have a problem using Dextron III in these transmissions. You know me, I'm cheap as the day is long. Which is one fo the reasons I do as much of my own work as possible. Last year I was up a WalMart buying it in the gallon jugs... and those three transmissions are still chugging along quite nicely.
The A604 and A606 transmissions are 3spd automatics with overdrive. It's the overdive components and 1st/reverse piston clutch seals that most often fail. The Torque Conveter often fails because the radiator ATF cooler saves the debris and then sends it to the Torque Converer when it breaks out. I flush my cooler once a year. Heat is another problem... and Caravan radiators that are leaking will destroy a transmission very quickly... low/no coolant means little heat transfer.
The 3spd automatics, non overdirve units also have torque converters in them. This is one of the reasons the Caravans gets such good gas mileage. I'd almost bet (though I don't know for sure) that the pistion clutch seals in the 3spds and the 3spd AOD are the same... One of the problems with the seals were quality control. Chrysler addressed this with update kit after update kit until the fixes were about 2 pages long. Today you will find that manuals are sold to reflect the basic transmission, and a second one reflecting the update kit. The seals have been updated by all manufactures and the failure rate is much lower.
Also, because of the failure rate of the transmissions, and owners being "gun shy" aobut them, the transmission rebuilders have been having a field day. Bring in a Dodge/Chrysler product with these transmissions... and lo and behold they all need a complete rebuild.
It's not Magic! It's just highway robbery.
Ofen this is not true. Failure on a dodge transmission throws codes that are read by OBDII compliant scanners. These codes will tell if the system problem is internal or external.
These transmissions are the first electronically controlled transmisisons and not mechanically controlled like the previous generations of transmisisons. The computer will tell the transmission when to up and down shift by opening and closing an electronic solenoid pack on the side of the transmission. This pack opens and closes hydraulic passeges which in turn enable and disable clutch packs via the pack cylinder piston.
That's part of the rub... If the computer senses a problem it thows the transmission into "Limp home" mode.. or 2nd gear. I know it happened to me while I was accelerating at 70mph up a hill. I thought the trannie had destroyed itself. I shifed into netural and back to OD. It worked fine... but two months later I was repalcing the speed sensors. These sensors are critical. Inside the transmisison, on each clutch is a ring gear with cut-outs. As a tooth goes by the sensor, the sensor sends a pulse to the computer. The computer counts the pulses per revoulition and knows the speed the clutches are traveling. Then upshift and downshifts accordingly. If the count is off the trnasmission can't shift correctly. If the count is lost.. the limp home mode is enabled. In my case the Caravan suddenly slammed into 2nd gear from OD at 70mph. You can imagine I was concerened.
How do you tell if you've got a bad sensor? Me, I really don't care... I know the cltuch packs are moving and the oil is free of debirs so that only leaves the possiblility of a sensor or the wiring. I keep the terminals tight, clean and packed with dialectric grease. That rules out a wiring progblem. There are two clutches, so there are two sensors. NAPA charges $18 for each sensor. That's pretty cheap! So, when I replace one sensor I repalce both of them as a set. It gives me peace of mind.