727 Lock Up Question

[Aussie Challenger]

I assume that you can get a lock up 727 trans, is the only difference in the convertor and what else would be needed to fit one to an E body?   
Is there a different case as well or can the standard one be modified?
Can a simple switch be adapted or is it a bit more involved?
Any help would be appreciated.   

[tactransman]

You need a complete 727 LU core. Then you need a a wire on a switch going to the solenoid connector on the case to supply 12 volts.

[Aussie Challenger]

Thanks Terry, I thought that might be the case, are there any years or models that are better than another for a lock up convertor 727 trans?   

[tactransman]

'79 in when they came out,they are pretty much all the same. The early 904 lock up's were all hydraulic and did not use a solenoid,I have not seen a 727 that way yet.

[Aussie Challenger]

Thanks again Terry, this will help when I get to sort out my other project.

Another question from your last reply, I have not had that much auto trans experience, I know that the 727 is stronger than the 904 but does the hydraulic lock up on the 904 have any advantages or weakness. Does the 904 look after its own lock up without driver involvement?  Thanks again.

[tactransman]

The 904 lock up has no advantage. It is controlled by a spring on a valve on the aux VB. The stronger the spring,the later the LU. The electrical style has the same set up,I would have to do some homework on the subject to see what the difference is between the solenoid style and non solenoid style. In the old days,they had problems with the LU apply and also of stripping the converter splines out. We had a standard procedure to block the valve with a rubber check ball inside the spring to eliminate LU completely.

[Aussie Challenger]

You have answered all my questions, I will just stick with the 727 electrical lock up, sounds like it is more reliable.  thanks Terry.   

[tactransman]

If you do get a 727 LU and it is NOT electrical let me know,I have not seen one yet! This is where the connector is located and what it looks like. 

[CUDA JAS]

Electric lock up....wait....what....hmmmm.

I have a lock up 727 out of a 19080 New Yorker in my cuda.  I am not aware of any switch wired to the lock up (the trans was in the car when I got many many moons ago).

So are you saying that in order for the trans to lock up, I need to put 12 volts, on a switch, to the solenoid on the trans (if the is one)?

[tactransman]

Electric lock up....wait....what....hmmmm.

I have a lock up 727 out of a 19080 New Yorker in my cuda.  I am not aware of any switch wired to the lock up (the trans was in the car when I got many many moons ago).

So are you saying that in order for the trans to lock up, I need to put 12 volts, on a switch, to the solenoid on the trans (if the is one)?

Do you have the connector in the above pic??

[Kapteenikosmos]

Not trying to steal this thread but how's the availability of performance torque converters for these later 727 with electrical lockup? How much punishment the lockup converters can handle?

The actual transmission dimensions are the same as older ones so they are direct bolt on to an ebody, right? Also is there a bick block version available?

To me, this seems to be a quite easy way to achieve some more cruising mpg with relatively little work...

[tactransman]

There is no big block LU's. The LU converters are not as strong as a NON LU. Transmission dimensions are the same LU and NLU.

[CUDA JAS]

Do you have the connector in the above pic??

No, my trans does not have a connector there. 

Does that mean my trans is not a LU unit?

When I had the trans apart, the converter body was 90 degrees to the ring gear, which I understood indicated that the trans was a LU unit.

[tactransman]

Still could be a lock up,just non electric. I have a feeling there is some 727 LU's NON electric out there.

Here is the best way to tell:


Lock Up VB


Non Lock Up VB

[CUDA JAS]

Still could be a lock up,just non electric. I have a feeling there is some 727 LU's NON electric out there.

Here is the best way to tell:


Lock Up VB


Non Lock Up VB

Thanks man, that is very helpfull.

It has been at least 10 years since I had the engine out, so I have no idea what the shaft looks like.  I have never had the trans pan off either, although I need to as it seems to be weeping quite a bit (probaly need a new pan).

At lease I know what to look for now.

Thanks Jason