Car Forum World

How can you tell or test a auto tranny converter to see if its good or bad?
i had my tranny rebuild and now when its changing it makes deafening sound or jerks, when its in cruising speed, it run good. but when you stop and go again this is when the problem is.

I own a shop, and there really is no way outside of doing a pressure test on it, and it either works, or it does not work. Your problem does not sound like a converter problem anyway. I may be wrong, but I just do not see anything inside a converter that could make it do this. Not knowing which transmission you have makes it hard to say what is causing the problem, but if you had it rebuilt, then you may have to take it back to have it adjusted. If it has a TV cable that goes down to it on the passenger side from the throttle arm on the carb/throttle body, then it may need adjusting, or you may have some tiny partical of dirt in one of the valves in the transmission causing this. A sticking piston in the valve body will do this, and it'll happen particularly right after a rebuild. This rings particularly true if the radiator was not cleaned out real well. Some stuff we used for many years that will fix this if its a sticking valve is "Lube Guard" and you may be able to get it at Advance Auto Parts stores. you'll want the one in the white bottle although. We used to call this stuff rebuild in a bottle, because it'll fix many problems with a transmission. The problem is, they took the whale oil additive out of transmission liquid, and since then we have had to use this stuff as a substitute. We put a bottle of it in every transmission we rebuild, and it cut our come backs down to near zero, so I have got to believe it works well. I would not be fast to jump on the man that rebuilt it, it may not be anything he did, but just one of those freak things that happens. Any reputable shop will be happy to take it back, and make it right. on occasion problems like these happen to new transmissions, and can drive a mechanic crazy, but they'll make it right if you go back. Remember they're only human, and to era is being human.
Glad to help, Good Luck.

Certified Master Mechanic, Shop Owner, 40 yrs. experience.

just had rebuilt bring back anmd complain