: Car jerking in 3rd gear



bossposse
01-15-05, 02:27 PM
Help mr wizard! may caddy jerks in 3rd gear, not shifting smoothly, i checked the tranny fluid, it looks like oil is mixed with it. what could this be? any help is appreciated. thanks

BeelzeBob
01-16-05, 03:33 AM
Help mr wizard! may caddy jerks in 3rd gear, not shifting smoothly, i checked the tranny fluid, it looks like oil is mixed with it. what could this be? any help is appreciated. thanks


Not likely oil (unless a "helper" poured engine oil into the trans)...

More likely, if the trans fluid is contaminated with something, it is coolant. The trans cooler in the radiator can allow coolant to enter the trans cooling circuit if the cooler fails. When the engine is shut down the residual pressure in the cooling system can push coolant past a leak and into the transmission.

Check the coolant for any signs of oil in it.

If the trans oil is contaminated , especially with coolant, you want to change the trans oil immediately. Drain the trans, the side cover with the hidden bolt under the lower pan and clean the screens. Refill the trans. Take one of the trans cooler lines off and route it to a bucket and start the engine. Let it idle while the trans oil pump purges the fluid trapped in the torque converter and the rest of the trans into the bucket. Keep pouring trans fluid into the trans. Do this until the oil from the trans cooler line is clean and fresh.

Coolant in the trans oil is very detrimental to the clutch plate material in the clutches so, if you do have coolant in the trans oil it needs to be removed immediately. The coolant causes the clutch plate material to flake off the plates. The trans oil needs to be changed and the trans needs to be purged of old oil regardless of what the contaminate is if it isn't coolant. But it is important to get any coolant out of the trans ASAP.