Hawk's First 727 Transmission Rebuild

[Brandy]

This is the build kit i used, recommended by Tom Hand.

https://redirect.viglink.com/?forma...1971-up/805589170?iid=320766785484&chn=ps

 

[HawkRod]

There's a complete video on how to do this on YouTube. It's about 2 1/2 hours and very detailed.

Thanks - good to know. I know there is tons of stuff on YT, but good to know there is a complete, detailed video out there. Some stuff on YT is pretty bad...

Btw, a GOOD set of snap ring pliers are your friend.

Noted! I have some decent ones, I think, but if not, I'll be sure to get what I need. I've used snap ring pliers a number of times so I don't mind buying another set if I need them.

An axle puller is overkill but his puller doesn't look like one.....

I'm afraid it is an axle puller, but I'll use it with a "light touch". It's all I had, so I'll make do with it.

I rebuilt mine a few years ago and posted a long, blow by blow thread on it, if you can find it

Start with post #660 on this page...

Thanks guys. I looked up both your threads.
@AR67GTX : As you suspected, your pictures are no longer visible, but it still might be a good reference. There are other good pictures still visible.
@Ghostrider 67 :Got it, and I see some good pictures for reference!

I really should have also said that all the "special tools" shown in the FSM aren't really required. I made my front drum compressor, a little steel, welder, Oxy/Acet torch to bend the steel to the curve required.

Awesome. This makes me more comfortable that I can make most specialty" tools I need.

To all for the suggestions and support so far: A huge thank you! I'll continue to post my progress as we go along!

 

[Brandy]

The Monroe book is a good one too but if you think you need it i's send you the one by Tom Hand. He was a Chrysler engineer and had a hand in designing these transmissions. Very good book with easy to understand directions tips and pictures..

 

[QOTHL]

The video on YouTube is a Chrysler tech video.

 

[Dave6T4]

The only special tools I had made up were drivers to push the oil pump and front drum bushings out. I worked at an automotive parts factory at the time that had an in-house tool room, so this was easily accomplished. A&A Transmission has a kit that puts 5 front clutch discs in a 4 clutch drum. Basically, the special front discs are the the same thickness as the rear ones. I always use the bronze thrust washer between the input and output shafts rather than the fibre one. I also remove the spring on the reverse servo piston assembly.

 

[AR67GTX]

The ladder frame support I used:

Have to really examine all the parts and take your time on them - especially when like me, you're a novice. The guys on here helped a lot too with evaluating parts and issues. I nearly missed the excessive wear on the thrust side of this planetary. I was looking at them closely because I had whine in lower gears which is usually from a planetary but the recess in the face of this gear was so smooth and looked like factory machining that it didn't register with me at first. It was only after I was having problems getting my end play into spec that I pulled it back apart and suddenly wondered if that was surface wear/erosion and not purposely machined like that. After asking and looking at pictures of new planetary gears I realized it was wear and got a replacement. My end play then fell into spec and my transmission is now quiet although I can say definitely if the wear/end play was the issue or the gears themselves.

 

[HawkRod]

The Monroe book is a good one too but if you think you need it i's send you the one by Tom Hand. He was a Chrysler engineer and had a hand in designing these transmissions. Very good book with easy to understand directions tips and pictures..

Thank you sir! For now, I will stick with the Munroe book, especially given that I may not need to pull apart subassemblies. However, if I get into trouble, I may very well take you up on your kind offer.

The video on YouTube is a Chrysler tech video.

I think I found it - time to start watching! Thanks for the extra tip about it being from Chrysler - made it easier to find.

The ladder frame support I used

Great visual - I may need to make something like this if I can afford the wood!!!

 

[66Satellite47]

The ladder frame support I used:

View attachment 1196112

Have to really examine all the parts and take your time on them - especially when like me, you're a novice. The guys on here helped a lot too with evaluating parts and issues. I nearly missed the excessive wear on the thrust side of this planetary. I was looking at them closely because I had whine in lower gears which is usually from a planetary but the recess in the face of this gear was so smooth and looked like factory machining that it didn't register with me at first. It was only after I was having problems getting my end play into spec that I pulled it back apart and suddenly wondered if that was surface wear/erosion and not purposely machined like that. After asking and looking at pictures of new planetary gears I realized it was wear and got a replacement. My end play then fell into spec and my transmission is now quiet although I can say definitely if the wear/end play was the issue or the gears themselves.

View attachment 1196118

Gee, in all my 727 work, never seen that. The 727's I've built/rebuilt for my drag cars(450-600 HP). Yours must have been a really bad rebuild to get that much thrust wear.

 

[Brandy]

I cut a hole in the seat of a tall chair and sat the trans case in the hole. Perfect height! I had the chair sitting around loose as the table was my work bench.

 

[AR67GTX]

Gee, in all my 727 work, never seen that. The 727's I've built/rebuilt for my drag cars(450-600 HP). Yours must have been a really bad rebuild to get that much thrust wear.

Could be - the previous owner was a transmission mechanic and claimed to have rebuilt it. But I found lots of stuff in the car that was just slapped together and half worn out. Took about two years before I finally stopped finding finger tight bolts in it.

 

[oldbee]

Just take it slow&easy. And remember, we have 'dvw' to call on if need be. He's probably forgot more than most of know!

 

[HawkRod]

OK. Picture dump coming, but for those doing this in the future perhaps this will be a good reference!

So, I cleaned my stainless steel workbench thoroughly and will use it as a parts lay down area.

I have an old table covered in plastic for my work area as I dismantle the transmission

Here is my assortment of snap ring pliers. Hopefully these will be enough!

I pulled the pan off of the transmission

Then removed the neutral safety switch

Then removed the 10 hex bolts that hold the valve body

Finally, removed the accumulator piston. There was no spring there.

 

[HawkRod]

More from disassembly:

Removed the rear extension housing snap ring, bearing and snap ring below.

Remove the clip on the governor valve and shaft

slide out the governor shaft

Then remove the snap ring and rest of the governor from the hole

Remove the snap ring and slide the whole governor assembly off of the shaft

Then, to prepare for removing the front pump, tighten the kickdown band adjuster to hold the front clutch retainer

I then laid down the transmission to prepare for front pump removal

 

[HawkRod]

LOL. OK, a quick note on reading vs. comprehension. The instructions clearly say to use a 3/8 bolt on the end of the slide hammer to remove the front pump. I skimmed over that when I read it.
Later, I pulled out a 5/16 bolt and decided that is what I needed for the slide hammer. Well, I was trying to slide hammer the case out. Of course, nothing moved. Luckily, I did it fairly gently so I don't think I damaged anything.

So, I built an adapter so I could screw on a 5/16 nut welded to a 3/8 threaded rod.

Then the pump came out easily by slowly and gently using the slide hammer side to side. Here i what it looks like from the back.

This is a picture of what you see in the transmission after pulling the pump out.

Next step is to loosen the kickdown band adjuster and take it out.

Then the unit comes out. The back of it looks like this. Note the small bushing in the center. Don't lose this.

Then remove the band (shown below) and associated pieces (not shown)

The inside of the case now looks like this.

 

[zyzzyx]

Well, Looks like you've got a heavy duty band in it! And there's that pesky aluminum hub planetary! Hey Hawk
what makes you think I can actually see the top of my work bench at this time????? That'll take a couple of days
to clear off and put away! Nice!

 

[HawkRod]

Well, Looks like you've got a heavy duty band in it! And there's that pesky aluminum hub planetary! Hey Hawk
what makes you think I can actually see the top of my work bench at this time????? That'll take a couple of days
to clear off and put away! Nice!

LOL! What makes you think it didn't take me awhile to clear my workbench off? There is ALWAYS tons of crap on it!

Nice that I have a heavy duty band, although this is in the "weak" 340 727 transmission. Hopefully the big block tranny will be beefy as well (or even beefier).

More disassembly:
I then slid the output shaft, driving shell and planetary assemblies out of the case.

Next step was to loosen/ remove the low and reverse band adjustment screw.

Then pull the low and reverse drum out.

Then pull the pivot pin out the case

Then pull the rear band adjustment parts out

Here is the band. Looks a bit rough, so maybe not in great shape?

I then removed the output shaft support

 

[HawkRod]

Finally (for now), I removed the overrunning clutch springs, rollers and race.
Simply pull each spring out (carefully), and the rollers and (inner) race fall right out.

I am almost done pulling everything out of the case. I have a couple of servos and other small details, and my goal is to get the rest of this out so I can clean the case super well. I don't want to pull the big block 727 apart until The small block case is clean and ready to go. This way, I can more quickly reinstall any/all parts that are in good shape.

 

[Brandy]

LOL! What makes you think it didn't take me awhile to clear my workbench off? There is ALWAYS tons of crap on it!

Nice that I have a heavy duty band, although this is in the "weak" 340 727 transmission. Hopefully the big block tranny will be beefy as well (or even beefier).

More disassembly:
I then slid the output shaft, driving shell and planetary assemblies out of the case.
View attachment 1196294

Next step was to loosen/ remove the low and reverse band adjustment screw.
View attachment 1196295

Then pull the low and reverse drum out.
View attachment 1196296

Then pull the pivot pin out the case
View attachment 1196297

Then pull the rear band adjustment parts out
View attachment 1196298 View attachment 1196300

Here is the band. Looks a bit rough, so maybe not in great shape?
View attachment 1196299

I then removed the output shaft support
View attachment 1196301

Four pinion planetary, nice!

 

[HawkRod]

Looks like you've got a heavy duty band in it!

Four pinion planetary, nice!

This shows what a novice I am at 727 transmissions; I didn't even know to look for this stuff! AAMCO rebuilt this is 1982 or so and it still worked great when I took it off the car. Hopefully when I transplant parts the big block tranny will still work well with those parts in it.

Disassembly continued:
To get the servos out, I simply used a large C clamp and a washer with a hole in it for the servo shaft. Worked great. The clips are removed with a small screwdriver, but this one was a bit troublesome to remove.

This is what it looks like coming out.

Then the snap ring, washer and spring are taken out from the shaft, and the shaft comes out.

Then the piston comes out. I had to use a small angled pick to grab the inside so I could slide it out.

The removal of the other servo is the same process as above. Below are what the parts look like coming out.

 

[HawkRod]

Then to get all the final parts out of the case:

I removed this plug in the front case near the pump to get the servo lever out (servo lever not shown)

Then I used a punch to gently pry out the outer race of the overrunning clutch

Then a screwdriver to remove this seal

Then I removed three of these plugs (I think they may be for testing pressures at various locations)

I checked the straightness of the case. Looks like it is off a maximum of .002". I'm not sure if that is good, I'm guessing it is. However, if it is not good enough, please let me know.

OK, so here is the case ready for a thorough cleaning. It just BARELY fits in my bead blasting cabinet, so I will try that to clean the outside of the case.

Disassembly complete!