94 3L 3spd caravan slips only on take off

[bombergp]

It just started couple days ago, sometimes only, pulling away from a stop it won't drive off immediatley when stepping on the gas, a sec or 2 later it grabs and stays ok shifting properly as long as I don't stop. If I go into neuteral at a stop, then drop to D and step on gas it never delays. Is this a selector fault? Thanks in advance for any help. It has 120k mi. I'm 2nd owner, fluid/filt. changed last @ 85k mi. dexron III, level ok good color, no odor.

[KManiac]

The 3-speed torqueflite in your van is a miniturized version of the RWD Torqueflites used in the 1960's and 1970's. It functions in the same way.

Drive Breakaway Low requires the positive engagement of the rear clutch pack and holding of the one-way sprag clutch on the rear planetary set. Failure of either one of these clutches will cause a slip. Let take a look at each of these separately.

Sprag Clutch - This clutch, a one-way clutch, holds the rear planetary set under acceleration, but allows it to spin freely when you back off the throttle, eliminating engine breaking in this range. Manual Low (Selector in 1) applies the low/reverse band to the rear planetary set, which allows engine breaking in low and overrides the effect of the sprag clutch, holding the rear planetary set both under acceleration and deceleration. If you had a problem with the sprag clutch, you would only be able to engage low with the selector in 1. Given your symptoms, this is not the problem.

Rear Clutch - This is a hydraulically actuated clutch that holds the internal gears in the rear planetary gear set. The clutch discs wear over time just like the clutch disc in a manual transmission car. Only two things will prevent rear clutch engagement, worn discs, or low fluid line pressure. If your discs were worn out, your van would not move forward. So we know that your clutch pack is good. If the line pressure was low, it would slip everytime you take off from a stop, regardless of what you do with the selector. And when I say slip, I mean that as you attempt to accelerate, you will see your tachometer jump above 2000 rpm, then drop down as the low range engages. Given your description, your line pressure is fine, as well.

What I think is happening with your van is that your Govenor is sticking and holding the transmission in a higher gear range as you stop the vehicle. The Governor is a centrifugal valve on the tailshaft. As vehicle speed increases, the governor slides outwards and causes the transmission to upshift. When you come to a stop, the governor is suppose to retract, causing the transmission to return to low range at a stop. When a govenor sticks and you attempt to accelerate, the car will chug like it is underrevving and will slowly accelerate without shifting. If the resistence of the governor is minor, the car will begin to accelerate sluggishly until the line pressure reacts and pushes the governor back were it belongs, then the transmission will suddenly catch first gear and begin to accelerate normally. Under this condition, the tachometer will hold at about 1000 to 1500 as it tries to accelerate in a higher gear, then pop up as low range engages.

If you suspect your governor is sticking, there is a way to test this. When you come to a stop, pop your selector in Neutral, then back into Drive. The Neutral range will cause the line pressure to react against the stuck governor, returning it to it's proper position. The transmission will operate normally after doing this. Based on your description, this is exactly what your van is doing. So I suspect you have a sticky governor.

Now, what causes a governor to stick? I will tell you. Somewhere in your transmission, a metal fragment has been shed and is now stuck in your governor valve bore.

The A604 three-speed was designed to be bolted to a 90 horsepower, 2.2 liter four cylinder. The 140 horsepower 3.0 Liter V6 pushes the stress limits of the internal components of these transmissions. If your van has been used under severe conditions, such as towing or numerous heavy loads, it has been stressed to it's limit. I have the same transmission bolted behind the 152 horsepower 2.5 liter turbo in my 1991 Dodge Shadow. For a period of time, the wastegate failed on my turbo, causing the engine to overboost and stressing the transmission even more. Right after I got the turbo fixed, I fragmented a clutch disc, causing the governor to stick. This occured at 89,000 miles. One year and 8,000 miles after rebuilding the transmission, it blew up again, this time shedding something that jammed the rear gear set and destroying it. Thank goodness I had a warrantee on the transmission.

Right now you have two choices. You can either live with it, meaning you can pop the selector into Neutral and back to Drive at every stop light, or you can have it rebuilt. My rebuild cost me about $1,900 three years ago.

Good luck and let us know what you find and do.

[waltham41]

Dextron III is the wrong fluid for a 1994 Dodge transmission if I am not mistaken, and can cause the problems you are describing. You should have used ATF +3 or Mopar 7176 in the tranny and it has been damaged by the use of the Dextron III

If the 3 speed is different than the 4 speed (which I own) and it is permissible to use Dextron, I apoligize for my mistake.

[KManiac]

Since it has been mentioned, your choice of ATF may be at odds. The owner's manual for my 1991 Shadow specifies ATF-3/Mopar 7176 for the 3-speed/lock-up. This could be a fluid issue, as well.

[RIP]

I "third" the fluid issue. Read all about it at Allpar.com. A fluid change to ATF-3 should be your first move. You have to get it flushed to get all the Dexron out. If you just remove the tranny fluid pan you'll only get 3-4 quarts out. If you're game there's a procedure to flush it in your driveway at Allpar.com.
Great post KManiac.

[neon_rt]

Who put Dextron III in the trans for you?
They should be buying you a new trans.
D3 will absolutely destroy the trans, usually in 10K miles or less.
I'm surprised you made it from 85K to 120K with the wrong fluid in it.
The detergent addatives in the D3 are not compatible with the clutch material and causes it to flake off, plugging stuff up as it does.
Your 3-speed auto may recover when you flush it and get the ATF+3 in it.
Putting D3 in a trans made for ATF+3 or 4 is usually a death sentence for the trans, a $2000 mistake the owner usually gets stuck with.

[bombergp]

I'm the goof who put dexron III in, but the manual said its ok if nothing else was available. I went to 5 stores until finding quaker state atf+3. I'm changing filter/fluid & see if it helps. I did the change to dex III at 96k now got 120k. Mopar 7176 is probably a dealer only item?

[neon_rt]

Walmart has ATF+3, cheap.
I use Amsoil ATF, but it is not certified by Daimler-Chrysler.
Amsoil claims compatibility to all ATF+ series. It has worked in both of my '00 GCs. One has had Amsoil in it for 100+K miles, the other 45+K miles.

[bombergp]

Thanks to all, especially KManiac, for sharing your knowledge. Last Sunday I changed to atf+3, drained 3.5 qt & fltr, teusday I drained/refilled 3.5qt also. As of yesterday the caravan began to delay at take off again sometimes, seems the longer it sits at stop its worse. It did also delay 1-2 shift while cold/begining of trip and toward end of 30mi trip back home. I needed to use seletor n-d on take off then drop-2 to help shift, but when in gear no slippage! Is it tough to clear out the governor, kmaniac mentioned?

[RIP]

If you don't want to flush it, consider changing 3-4 quarts at a time a couple more times. Won't get all the Dexron out but, you'll get most of it. I use a small pump to suck it out the fill tube. Don't have to hassle with the pan and it works great.

[bombergp]

Hope this gets to the front. I think I have my trans probs. fixed after changing fluid out SIX TIMES! Filter twice. It would let me know at 25mi. after by coming back to same symptoms. Now I've put 250mi. on her and its still good so I think its fixed. Each change gave some fuzz around the magnet and the last one a fair sized chip 1/16 X 3/32L, maybe the clogger.

[Buzzkill101]

yeah you have to remember that when you change fluid that there still is 3 qts or so in the differential. that's why it probably took soo long to cure

[AwPhuch]

DEX-III = BAD!!!!

Change it before it costs you $2000...whats 30 bucks to 3000?

Brian
AwPhuch