Help with 727 trans build.

[ramsportman96]

I am looking for guidance on what will be needed and or must haves, for my 727 rebuild. 640tq and 580hp on radial tires. I am hoping for something that will last a while, and not kill my neck every shift. Can anyone steer me in the right direction on a parts list?

[pschlosser]

hard-shifting is more efficient, and transfers more energy to the wheels than a mushy-shifting transmission.

as for parts, the OEM 727 can handle those HP numbers just fine. 

So if you're looking to rebuild yourself, get the book "Chrysler TorqueFlite A-904 & A-727: How to Rebuild" by Tom Hand (Amazon)

Seek a decent rebuild kit.  The more deluxe one is the B & M Transkit #10229.  Their detailed instructions are superb, and the kit contains everything you need to rebuild it.  There are optional parts included, and optional instructions so make it shift harder, or even softer, depending on preference.  Each mod is described, so you can decide if you want to include it.

I've been driving on a 727 I rebuilt back in the 1980s with one of those kits, and it still shifts great.  When I get on it, the shifts are so fast it chirps the tires.  At light throttle, the shifts are fast with a clunk, but nothing distracting or jarring.

If you need replacement parts (kind of rare, unless the tranny was really abused) the best source I've found is http://www.aandatrans.com/  They have great support, and even heavier duty variations of parts, if that's your thing.

Special tools?  Yes, a few things,  But the Tom Hand book will describe them better.  I recall having to buy a decent set of snap ring pliers.  And some "square drive" sockets to remove plugs.

[chargerdon]

Here is a quick guide.  Pay attention to the identification section..  https://www.forbbodiesonly.com/moparforum/threads/your-guide-to-the-727-904-transmission.17287/

In addition youtube has several how to videos on it.   I rebuilt both a 904 and then later a 518 by watching youtube videos.  Its actually pretty easy so long as you have the right rebuild kit...  Thru the years there were many many differences in what is needed.  So again make sure u identify your 727.

Tools..in addition to the snap ring plier set you will need a slide hammer for getting out the front pump...(there is a utube on how to make one)  Also u will need a spring compressor tho u can make one pretty easy.  I also constructed a bench so that i could put in in to hold vertically...makes reassembly a lot easier !  Also, in my belief dont bother buying a rebuild manual.   They talk a lot about number of clutches an tolerences to measure.  One video i watched said if your transmission is stock..dont bother measuring anything just put it back together as it was right from the factory !! 

[MoparLeo]

Here are a few youtube videos on the 727.
https://www.youtube.com/watch?v=eUCsjEW1d9w
https://www.youtube.com/watch?v=qgdpfLnprYc&list=PLhCiXHwyBtSHv6ZcbV5G5J-JE_uyE_HJV

[Bullitt-]

  One good modification I'm aware of is a bolt in sprag
       Stock sprags can can fail in certain circumstances
  I learned about this from Terry Coppedge aka tactransman

In a Chrysler 727 Torqueflite transmission, the sprag (also known as the overrunning clutch) can fail due to abuse, such as aggressive shifting between forward and reverse gears, or excessive wheel spin, particularly in first gear during burnouts or when spinning the tires on wet pavement. This can lead to the sprag's vertical tabs being flattened, causing it to fail and potentially damage other transmission components

video of installation with explanation of different bolt in spargs
https://www.youtube.com/watch?v=lQWFQhda7nk

sprags in video
https://www.andrewsracingtrans.com/727-torqueflite?Category=727+Sprags

 Terry also recommended this TransGo TFSC shift kit to me that does not alter the shift pattern https://www.oregonperformancetransmission.com/product/TRG-SKTFSC.html
 
Video of install of shift kit https://www.youtube.com/watch?v=WKpRfr7UtUQ