[brucet]

HI,
Hope you trans experts can help
Background: 1999 Sable with DOHC AX4N, 77,000 miles. Car was running fine and shifting fine, transmission just stopped working at a stop sign. took out trans expecting to rebuild and found pump shaft splines in converter were stripped. Replaced torque converter with reman from NAPA.
Problem: car shifts just fine, but when driving at constant speed or very slight acceleration, the car will studder or shudder. no change in rpms. most of the shifts into 3 or OD will also have the slight shudder. No shudder over 60 mph. no shudder with hard acceleration.
I suspect it is related to torque converter lockup, but don't what makes lockup work.
any ideas on how to diagnose?

thanks
Tom

 

[egiroux]

How's the fluid level. I assume you put new Mercon V fluid and a new filter in it when you did the work.

 

[brucet]

yep, i think it was about 12 qts

 

[Monsoon]

I had a friend with the same type symptom. Turn out to be a bad plug wire. The spark would jump from the cable to the block at intermittent intervals. This was fun to watch at night because you could actually see the spark jump to the block. This made the engine/transmission stumble at highway speeds and at random times. And the car had about the same mileage as your Sable.

Verify your car isn't throwing any trouble codes for cylinder miss.

Monsoon

 

[brucet]

doesn't feel like an engine miss, pretty sure its trans. no trouble codes showing. will try looking at night though

thanks

 

[sheila]

Maybe r&r vss? Almost a maintenance item on a 99tec ax4n.

 

[brucet]

Sounds pssible, i will try when i get a warm er day

thanks
Tom

 

[sheila]

^ $18-20 at az. Borg-warner vss about $5 more at oreilly or advance auto.