Torque convertor swap

[64Belvedere]

Ok, I've been getting conflicting info from various sources, so will a convertor that is currently in a 63-64 727 work in a newer 72 and up non lock up trans? As far as what I've read, the splines are different. Will the convertor fit onto the input shaft at all or are they completely different? I know that the early ones are supposed to be 19 splines and the newer ones 24. Thanks.

 

[Mr Belvedere 30144]

A-727 transmissions from their inception until 1966 have 19 splines on the input shaft. Non-lockup 727 transmissions from 1967 onward have 24 splines. Lockup 727 transmissions that debuted in 1978 had 23 splines.

Not all 727 transmissions made after 1978 were lockup; specifically towing package 727 transmissions commonly were non-lockup, and would have the '67-onward 24 spline input shaft. The A-518 overdrive also has 23 splines. The output shaft has 29 splines.

So the answer is no your TC will not work on a 72 TF.

 

[64Belvedere]

That was my understanding as well. Especially after reading some books on them, and emailing with John Cope from Cope trans. This morning we counted the splines on a 64 cable valvebody trans that is sitting on the floor in the barn. It's an unmolested trans pulled from a 64 car. 24 splines on the input shaft. My buddy also asked a local chap who currently has a 64 aluminium nose car and another steel nose maxie. He has had at least a half dozen other 64 Fury/Belvedere/Savoy cars over the years and he said he has never had one with a 19 spline count He said he has always used a later converter in them. I am confused.

 

[Garys1969RR]

I would talk to one of the T/C manufacturers, like TCI. Or you can see if the T/C you want to use will actually fit the transmission you are using.

 

[Photon440]

A couple of 19 spline examples:

http://www.ebay.com/itm/Torqueflite...ilt-HIGH-STALL-Torque-Converter-/221322622784

http://www.moparmusclemagazine.com/...7_transmission_torque_converter/photo_06.html

 

[Greg Ducato]

I have been in the trans business for 34 years, I have never seen a pre 67 727 trans with 24 splined input unless someone changed the stator support and shaft. A lot can happen in the lifespan of a 50 year old transmission....

 

[Garys1969RR]

I have been in the trans business for 34 years, I have never seen a pre 67 727 trans with 24 splined input unless someone changed the stator support and shaft. A lot can happen in the lifespan of a 50 year old transmission....

Thats what I thought. I have swapped converters and transmissions/valve bodies of many different models/years, and never had a problem. Lots of mix and match. They always worked.

- - - Updated - - -

Some T/C can be hard to get all the splines to stator and input shaft aligned, and slots to front pump lined up so it will slip on all the way. But eventually they do.

 

[64Belvedere]

I have been in the trans business for 34 years, I have never seen a pre 67 727 trans with 24 splined input unless someone changed the stator support and shaft. A lot can happen in the lifespan of a 50 year old transmission....

Well, we'll know for sure when we pull the one out of the car and try the converter from the car on the new trans. It's a 63 trans in the car currently. My thoughts are the same as you all that the input shafts must have been switched at some point during the life of the car. After the books and manuals I read, that's all I can figure.

 

[Photon440]

Places like Mopar Muscle or Mopar Action magazine often mention in their help column that it's easier to change the input shaft than try to get a special stall converter for the earlier torqueflites, so that's not an unlikely occurrence.