Expert: Roland Finston - 7/25/2011

Question
scanner read no errors at transmissions controller.
Foaming could be couse of not engaging drive or reverse.
But What is cousing foaming? Fluid itself - rather not its new.
Some leak at the halfshaft inner CV Joint its a little bit leaky?
I'm still confused about it.

Or maybe tranny filter is clogged by Oil from PTU (when I putting in tranny with PTU some part of PTU oil reached tranny oil)

I've got problem with my 2000 Dodge Grand Caravan 3.8 AWD with transmission. After several issues with A604 I've finally managed to back on the road. Lately I replaced torque converter - not new but from yunk yard (oryginal was locked-up forever :( ). After that it's was all ok, but recently I discovered that I can't move when I move lever to D,3,L or R OR when  moving - slowly 20km/h A604 acting like Neutrals and no go. I checked fluid level add a little. (oil used ATF+4 red clear colur, not burned) but foaming a lot.
What could cause foaming or how to determine and how to solve it at low cost?
If I remember correctly , in the Torque Converter I've seen some water spots - I've tried to exchange it by fresh fluid one but I've changed only 1/2 liter only.

ANSWER: Hi Krzysztof,
The fluid in the torque converter is part of the overall fluid of the transmission system which totals to about 10 quarts and is constantly flowing through the converter. If you want to change out all the fluid you have to power flush it to get it out of the trans/converter/cooler/connecting lines.
Other than that, have you tried for a fault code readout using the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time? Then watch for the mileage reading in the odometer window to change to show any 4 digit numbers preceded by a P. Let me know of any and we'll go from there.
Other than too much or too little fluid in the system I don't have a suggestion for foaming other that there being contamination of the fluid.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi

I've changed the oil ATF+4 4liters, no filter change ($$ limited, oil I've already have), no changes, no codes (checked on scanner). CVI in half of it's values. Nothing changed. Still oil foaming (not so much - but it's visible.

Suggestion form owners and mechanics - clogged or  dirty Valve Body.
Any other suggestions??

ANSWER: What do you mean by "CVI in half of it's values"?  Do you mean the pressure tap measurements are all half of what they should be? If so, and all are low, that would mean a defective pump, a clogged filter, or s stuck pressure regulator.
I have seen the term CVI, but I don't think there is a table of proper values for your transmission.

---------- FOLLOW-UP ----------

QUESTION: CVI Values
LR 57
2-4 52
OD 126
UD 74
They are not changed for 2 years. In mean time there was couple fluid and filter changes. only after TC change - shortly after this tranny appears strange.
Answer:    Hi Krzysztof
The CVI values for LR,2-4,OD are in the acceptable range, but UD at 74 is above the limit of 70.
This is possibly indicative of an accessively worn UD clutch. Whether that would cause foaming is unknown to me. Again, have you tried to get a fault code readout from the memory of the transmission controller? That would possibly explain the problem.
Roland

Answer
As far as I have seen, foamy oil can be caused by both too high and too low a level of transmission fluid. So look at your dip stick after running the engine in Park for a minute and on level ground. The level should be in the 'cold' region if it is at 80F. After the engine has been driven enough so that the temp of the fluid reachs 180F it should read in hot region.
in between those two temperatures the level should be proportionately displaced between the hot/cold cross-hatched region. Use a thermometer to check the temp of the fluid.
The torque converter, transmission and differential all share the same Chrysler ATF+4 fluid so there should be no contamination issue. Have you only used +4 type fluid?
Roland