Imperial Home Page -> Repair -> Transmission -> Torque Converter
Question from Dave (1960):
can anyone supply the part number for a 413 converter for a '60 Imperial. I managed to get a NOS one a few years ago, but is slightly smaller in size. The converter seems to now have a drain back problem which is irritating to say the least. The converter might be for a lighter car as a Plymouth or Dodge but can not confirm this.
Dave, I can't help you on the part number, but I can tell you that a smaller converter is probably a "higher stall" unit. That means it slips more and multiplies torque more. Some may claim that this is better for a heavy car, and indeed might help low speed acceleration. However, I prefer the low stall units in my torquey 440's since it generates less heat and has less slippage at higher speeds.
What do you mean "drain back" problem?
The drain back problem is not serious as long as the external seals on the transmission are in good shape. These seals are used where the shift cable goes in, the neutral safety switch, etc. If these seals are not dried out, the fluid will simply go back into the torque converter once you start the car. If they are dried out, the fluid will overflow and spill out on the ground after the car has been sitting for a few hours.
After replacing the torque converter on one car twice, and still having a mess on the garage floor, I was told about this and haven't had any trouble since.
Your problem seems a little more severe, but most Mopar people will tell you to warm the car up in neutral rather than park I believe it's because the Mopar trans pump isn't fully engaged in park. Almost all my cars are stick, but this is how you are supposed to cope with Mopar tranny "morning sickness." It might help.
On all my Imperials ('65, '70, and '71), when the car is cold, I start the car in Park as usual, then shift to Neutral. It only takes about 10 to 20 seconds in Neutral for the transmission pump to re-fill the torque converter, and away you go!
1731 860 is the original torque converter for the '60 Imperial.
I do the same thing when my '66 or '73 is cold. I start the car in park and then shift to neutral for about 15-20 seconds to fill the torque converter. If you try to move the car without letting the torque converter fill up the car doesn't want to move.
My '66 FSM for my "lesser" MoPar has instructions to idle in neutral for a short period before engaging the transmission of a car that has been sitting for a while. My folks were told the same thing when they bought a new '66 "lesser" MoPar. It has always worked for me, so I haven't agonized over it.
Question from Demetrios (1968 lock-up converter):
My '68 LeBaron has a lockup converter. I suspect the whole transmission is from a '78 model year car. The lockup operation was not consistent for a while, but now is even worse. Its completely locked up. Its like driving a standard with no clutch. Is there a way I can disconnect the lockup without overhauling the whole transmission? My goal is to continue driving the car for a while till other parts of the tranny eventually fail...
Reply from Mikey:
It is proably possible to disable the lock up function of your converter. The first generation lockups , well...they sucked. It was a case of a good idea let loose before the technology available to make it reliable and user friendly was up to speed.
I am quoting from the ATSG ( Automatic Transmission Service Group ) 727 Torqueflite Manual:
Will not Unlock:
Sticking fail safe valve
Sticking lock up valve
Sticking switch valve
Valve body malfunction ( They usually mean warped or damaged vb at this point )
Sticking governor valve
Question from Anthony (1972):
Does anyone know if their is a drain plug on the torque converter of a Chrysler 727 transmission?
Should be an access cover at bottom of converter case/then move converter until drain plug lines up with opening.
There should be a drain plug on that converter providing it's an original converter.. They eliminated drain plugs around 1975.
Question from Joel (1972):
How would you know if a torque converter was bad?
Reply from Pete:
Aside from vibration issues caused by broken off pump/turbine vanes, a torque converter fails because the stator oneway clutch fails and you don't get torque multiplication (the big advantage of an automatic transmission). To check for this problem you do a "stall test" as outlined in the FSM. This is a scary test involving a securely set parking brake, a firm foot on the service brake pedal, and a fearless foot on the accelerator. Basically, you brake torque the engine until RPMs won't increase any more. The test must be performed quickly to avoid overheating the transmission. Read the FSM!
This page last updated June 15, 2004. Send us your feedback, and come join the Imperial Mailing List - Online Car Club