Transmission worked fine for about three days then suddenly quit pulling in all gears?

ALIENSON

MEMBER
2004 CHEVROLET VENTURE
3.4L
V6
2WD
AUTOMATIC
200,000 MILES

Transmission cooler leaked. We changed the transmission filter, replaced transmission fluid and pumped old transmission fluid by open coolant line until transmission fluid was clear to flush torque converter. Flushed radiator. We installed a new external transmission cooler and capped off old cooler lines in the radiator. Transmission worked fine for about 3 days then suddenly quit pulling in all gears. No noise no slipping just suddenly stopped pulling. Shutting van off for a few minutes seems to allow transmission to pull very slowly without too much throttle. Had to shut down three times to go about six miles home. Transmission fluid is full and clear with no smell (new). Could TCM need reset. Thank you

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

You must use the correct transmission fluid for the unit to work.

Fluid Types

Transmission Fluid Type

Type .................... DEXRON III or Equivalent
Capacities

Transmission Fluid

FWD

Pan Removal .................... 7.0L (7.4 Qt)

Overhaul .................... 9.5L (10.0 Qt)

Dry .................... 12.0L (13.0 Qt)

AWD

Pan Removal .................... 8.3L (8.7 Qt)

Overhaul .................... 10.3L (10.8 Qt)

I would check the fluid level again because you might have had air in the fluid. It must be Dexron III fluid. Also, when you disconnected the fluid cooler from the radiator you may have cut down the fluid flow as well due to the aftermarket cooler. Let's run the codes to see what comes up.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/automatic-transmission-problems

Please go over these guides and report back.