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727 rebuild at home

Rusty knuckles

Rusty knuckles

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Im a very handy guy and I need to pull my trans this winter and rebuild it. I have no issue following directions or the service manual but my big concern is, am I going to need any specialty trans specific tools to work on it?
 
A decent spreader pliers for the tailshaft snap ring is handy.
I used a couple of c clamps for compressing stuff.
I did my first one last winter.
This site is a great resource.
 
Snap ring pliers. Large C-clamp to compress kick down servo piston. Smaller C-clamps to compress front drum spring retainer. Drivers to push out and install front drum and oil pump bushings. Slide hammers to pull front oil pump. Feeler gauges and 0-1 mic's to set clutch clearances Other than that, it's not too bad. I've done over a 100 of them.
 
Dave6T4 said:
Snap ring pliers. Large C-clamp to compress kick down servo piston. Smaller C-clamps to compress front drum spring retainer. Drivers to push out and install front drum and oil pump bushings. Slide hammers to pull front oil pump. Feeler gauges and 0-1 mic's to set clutch clearances Other than that, it's not too bad. I've done over a 100 of them.
Click to expand...
I totally agree. Kim
 
Dave6T4 said:
Snap ring pliers. Large C-clamp to compress kick down servo piston. Smaller C-clamps to compress front drum spring retainer. Drivers to push out and install front drum and oil pump bushings. Slide hammers to pull front oil pump. Feeler gauges and 0-1 mic's to set clutch clearances Other than that, it's not too bad. I've done over a 100 of them.
Click to expand...
Good list here, but You don't need any slide hammers. First pic shows at the races on the pavement repair.

Thread a 3/8" bolt into the front pump holes @9 and 3 o'clock positions they are threaded, pry out pump body with a hook type prybar. A little bit each side and it's out in 5-6 prys. Last photo.

Bushing drivers a must, always put in front pump and forward clutch bushings.

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If there is a repair book on the 727, get it! It will have tips & you can make sure things are done in the right order.
 
Dipping my toe for the 1st time in one today. I have 0 to1 mics, Carl's book, C clamps and some fresh snap ring pliers. Get decent ones, the ones at Autozone etc with the detachable ends will NOT hold up. I bought these and so far perfect. There is also an original Chrysler 727 tech video on Youtube that is awesome to watch. Makes it quite simple but it is very indepth throughout the valve bodies also

20250727_111535.jpg


20250727_111723.jpg
 
The 727 is very easy to rebuild. No special tools needed as mentioned before. Pay attention to clutch pack
clearances and replace everything that looks worn. When you're close to done and setting the end play,
set the transmission directly on the output shaft with the bell housing pointed straight up so all of the weight
is on it. measure your end play and shim it accordingly. That's the hardest part! Good luck.
 
I always measure total endplay prior to disassembly and again before pump o-ring is installed.
 
You need two different types of snap ring pliers.
For the clutch pack, servo, and tailshaft snap rings. The snap on pair jaws open parallel and work much better than the third photo.
Many on eBay for about $50. https://www.ebay.com/itm/306404112796?

Pair with red handles will work but slip off as jaws open on an arc.

Last pair with points will need these for the snap ring on the output shaft and governor weights.



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To be honest endplay isn't much of issue. Neither are the bushings. The only bushings needed would be in the pump or tailshaft housing. The most difficult part of the job is seating the front clutch piston. Since the seal sets in a blind hole and the piston can not be rotated. Using 3 c clamps or C clamp style vice grips works well. Tighten each one a little bit at a time and the piston seal will seat down in the drum. If you have a drill press? a piece of slotted muffler tubing (snap ring access) with the head pressing down on the front drum retainer will work when install the snap ring. Easier with two people. It can be done with the above mentioned C clamp vice grips (2 pair) and a vice. Inovated a lot of tools when I was first building these in the 80's at home. Built drivers for the two metioned bushings on a lathe. Be aware if you install a tailshaft bushing. Test fit a yoke or your driveshaft. You may have to burnish it. Ran across many tight ones in the last few years. Air check the clutches on th epump before reasmbly. A hole in the work bench is helpful here. doing 3 727's, 1 904 in my shop being done currently.
Doug
 
I hope it goes well, it's great feeling when you fire it up finally and it works :)

BTW.. i bought these for getting the snap ring off the tailshaft bearing.. can do it with screw drivers, but this was just much easier.. could probably also use them for the drum clip shown above.. (i did make the jaws a little skinnier to fit in the tailshaft bearing slow)
 
Like Doug posted, lube up everything especially that blasted frt.clutch seals. I got extremely lucky on the couple times I did a 727, never air checked and always worked great.
 
Air checking doesn't make them work any better. It's just a test before it's in the car.

I quit air checking after the first few.

Front clutch on 727 I just lube them well, you can move the piston side to side while a slight push down and they go in easy enough. Clamps seem like a bad idea.
 
I made a 727 front clutch spring compressor tool from scraps I had laying around the shop. In the background is a Snap-On snap ring pliers. Expensive, but the phrase buy once, cry once definitely applies...

DSC03682.JPG
 
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