727 Rebuild: Some Questions

[70runner]

727 for street car behind 9.5CR 440-6. Have already installed Transgo TF-2 to firm up shifts and such.

Tranny does not have accumulator/spring...and was running OK without. I have an accumulator/spring from a donor 727. Should I install the accumulator/spring? I understand this will soften the 1-2 shift. I believe installing the accumulator with a blocker rod will firm 1-2. Suggestions appreciated.

The front clutch drum bushing needs replaced and is sitting about 1/4" down in the drum bore. Shouldn't this bushing be installed to line up with the bottom of the bore chamfer, about 1/16" down? Hope this makes sense.

Lastly, I don't expect to have the engine done for another month or so...should I soak the clutches now, reassemble the 727 or wait until the engine is ready to soak/reassemble?

 

[fishy68]

727 for street car behind 9.5CR 440-6. Have already installed Transgo TF-2 to firm up shifts and such.

Tranny does not have accumulator/spring...and was running OK without. I have an accumulator/spring from a donor 727. Should I install the accumulator/spring? I understand this will soften the 1-2 shift. I believe installing the accumulator with a blocker rod will firm 1-2. Suggestions appreciated.

Install a blocker if you want it to shift firmer. Note: If your running a high stall converter it will soften the shifts somewhat so keep that in mind. Note2: Without a blocker rod holding the accumulator piston it slams back and forth in there and can break so a blocker rod should always be used if there is no spring in it. If you want a softer shift install a spring

The front clutch drum bushing needs replaced and is sitting about 1/4" down in the drum bore. Shouldn't this bushing be installed to line up with the bottom of the bore chamfer, about 1/16" down? Hope this makes sense.

Your right it should be about 1/16" down. Not 1/4" down.

Lastly, I don't expect to have the engine done for another month or so...should I soak the clutches now, reassemble the 727 or wait until the engine is ready to soak/reassemble?

You can do it now. I've rebuilt transmissions and they sat for a year without any problems.

 

[70runner]

Thx for reply - much appreciated.

I'm leaning toward the hughes 2500 converter. It sounds like the blocker would increase the 1-2 firmness, already increased by the TF-2 kit. OTOH, by softening the 1-2, the spring might counteract the TF-2 effects. Given the 2 choices, seems like using the spring might be the best option if I don't want a harsh 1-2?

 

[fishy68]

Thx for reply - much appreciated.

I'm leaning toward the hughes 2500 converter. It sounds like the blocker would increase the 1-2 firmness, already increased by the TF-2 kit. OTOH, by softening the 1-2, the spring might counteract the TF-2 effects. Given the 2 choices, seems like using the spring might be the best option if I don't want a harsh 1-2?

actually the TF-2 doesn't really firm it up a lot if you don't go wild drilling out the hole that controls the 1-2 shift in the transfer plate. I can understand not wanting a harsh shift but with a 2500 stall I doubt it'd be anywhere close to harsh even with a blocker rod. If your worried you can always install the spring and if it doesn't shift firm enough for you take it back apart and install a blocker. That's what I ended up doing. When I first put my car together with a fresh trans. and TF-2 kit installed I had a 2200 stall in it and the 1-2 shift was pretty soft. I replaced the spring with a blocker rod and it's perfect. You can feel it but it's not harsh. Under full throttle it would chirp the tires slightly until I put drag radials on it. Now it just goes.

 

[70runner]

actually the TF-2 doesn't really firm it up a lot if you don't go wild drilling out the hole that controls the 1-2 shift in the transfer plate

I drilled on the conservative side for the TF-2, street specs.

If your worried you can always install the spring and if it doesn't shift firm enough for you take it back apart and install a blocker. That's what I ended up doing.

Good plan---I'll use it.

I got the whole 727 apart today. I'm using a 727 from 69 Chgr as donor. Following pic shows 2 output shafts, the "gold" one from the Chgr, the other is from the 727 I'm rebuilding. Is there any significance to the "gold" tint?

I dry packed the front clutch and measured the clearance at about .45 with a .74 snap ring. My FSM says the spec is .25 to .45 but ideally should be closer to the lower number. A .88 snap ring should get me to about .30. Is this worth doing or should I just leave it?

Thx again for your help.

 

[fishy68]

I drilled on the conservative side for the TF-2, street specs.



Good plan---I'll use it.

I got the whole 727 apart today. I'm using a 727 from 69 Chgr as donor. Following pic shows 2 output shafts, the "gold" one from the Chgr, the other is from the 727 I'm rebuilding. Is there any significance to the "gold" tint?

Hum... That's a new one on me. Never seen a gold one before and I've torn apart so many I can't remember. The only diff. in output shafts (of the car variety) is 76 and up use a different spline angle where the planetaries slip on so you can't mix 76 and up parts with 75 and back parts.

I dry packed the front clutch and measured the clearance at about .45 with a .74 snap ring. My FSM says the spec is .25 to .45 but ideally should be closer to the lower number. A .88 snap ring should get me to about .30. Is this worth doing or should I just leave it?

Thx again for your help.

I assume you accidentally left out your zero's there as the clearance should be .040-.060 and the snap rings are .074 and .088". Clearance depends on how many friction discs your carrier uses. It's probably the common 4 disc carrier so .045 is plenty tight. I wouldn't go tighter. I use the .010-.015" per friction disc rule for clutch packs and it always seems to work fine.

 

[70runner]

My apologies...left out the zeros. The shafts look identical except for the odd gold tint. The Charger 727 was supposed used on a race car for a few runs. Perhaps some sort of hardening?

Yes, its a 4 disc drum, so I'll leave it at .045" as you recommend.

...this 727 rebuilding is interesting stuff :read2::read2:

 

[fishy68]

My apologies...left out the zeros. The shafts look identical except for the odd gold tint. The Charger 727 was supposed used on a race car for a few runs. Perhaps some sort of hardening?

Yes, its a 4 disc drum, so I'll leave it at .045" as you recommend.

...this 727 rebuilding is interesting stuff :read2::read2:

No problem. I figured it out easy enough. I was thinking the same thing on the tint that it may be some kind of hardening.

Torqueflites are fun to rebuild. If you like reading and want to know more about Torqueflite's there's a real good book out on them. Here's a link to it on www.amazon..com

[ame="http://www.amazon.com/Torqueflite-727-Transmission-Handbook-HP1399/dp/1557883998/ref=pd_rhf_p_t_1"]Amazon.com: Torqueflite A-727 Transmission Handbook HP1399: How to Rebuild or Modify Chrysler's A-727 Torqueflite for All Applications (0075478013999): Carl Munroe: Books@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51MrlOqCiXL.@@AMEPARAM@@51MrlOqCiXL[/ame]

It is well written and easy to understand. Tells everything from basic design and modifications and how to do a stock rebuild to an all out racing build. Well worth the $15

 

[crackedback]

Technical Videos has a tape/dvd re: rebuilding 727's

Paul Zank does the tape. Very helpful and has many shortcuts and tips.

 

[70runner]

Torqueflites are fun to rebuild. If you like reading and want to know more about Torqueflite's there's a real good book out on them. Here's a link to it on www.amazon..com

Amazon.com: Torqueflite A-727 Transmission Handbook HP1399: How to Rebuild or Modify Chrysler's A-727 Torqueflite for All Applications (0075478013999): Carl Munroe: Books

It is well written and easy to understand. Tells everything from basic design and modifications and how to do a stock rebuild to an all out racing build. Well worth the $15

EXACTLY the book I'm using. I spoke to Mr. Monroe the other day - ordered some parts from him. Nice fellow.

Interesting discovery on the overrunning clutch. Looks like the inner cam wore a groove in the housing (pic). Both my 727s have this groove - I suspect it is common. Is this something to be concerned about?

Also included a pic of the outer cam (sprag?) which has some wear where the rollers ride. Not enough experience to know whether this is OK or something to be addressed.

crackedback...thx for the video reference, I'll check it out

 

[fishy68]

I've only seen one have a slight groove in the housing from the over running clutch. It wasn't anywhere as bad as the one in your picture. You could just barely feel it with your fingernail. All the others I've done were fine.

You ever seen that happen Rob?

 

[70runner]

I've only seen one have a slight groove in the housing from the over running clutch. It wasn't anywhere as bad as the one in your picture. You could just barely feel it with your fingernail. All the others I've done were fine.

You ever seen that happen Rob?

Both my cases have the groove, much deeper than fingernail check. Can see the wear on the inner cam (pic). So I guess that brings me to ... do I need to find a case w/o the groove?

 

[fishy68]

That is sure odd. I have never seen a race scored like that on a torqueflite. I wonder if someone had the end play set too tight?? I think I'd look for a different case and sprague race. In the book you have it outlines a oil mod to do to the over running clutch.

 

[70aarcuda]

Technical Videos has a tape/dvd re: rebuilding 727's

Paul Zank does the tape. Very helpful and has many shortcuts and tips.

Good price for that video....

Live from Laughlin NV working Nights to keep from being a bake potato

 

[70runner]

That is sure odd. I have never seen a race scored like that on a torqueflite. I wonder if someone had the end play set too tight?? I think I'd look for a different case and sprague race. In the book you have it outlines a oil mod to do to the over running clutch.

I did a bit of surfing and discovered the following kit made by TSR (Munroe) here:

A-727 Case Repair Bearing [FONT=Arial, Helvetica, sans-serif]Year 1962 up. This bearing will repair cases damaged by the inner overrunning clutch race hitting the inside rear of the case. Includes bearing and instructions. Machining required.

The "machining required" note causes some anxiety, but apparently this issue is sufficient to warrant a repair kit. I sent an email to Munroe asking him about it.

[/FONT]

 

[fishy68]

I did a bit of surfing and discovered the following kit made by TSR (Munroe) here:

A-727 Case Repair Bearing [FONT=Arial, Helvetica, sans-serif]Year 1962 up. This bearing will repair cases damaged by the inner overrunning clutch race hitting the inside rear of the case. Includes bearing and instructions. Machining required.

The "machining required" note causes some anxiety, but apparently this issue is sufficient to warrant a repair kit. I sent an email to Munroe asking him about it.

[/FONT]

Interesting. I've seen GM Turbo 400's with this issue but never a torqueflite.

 

[70runner]

I wanted to thank you again for your responses/help.

Now the search begins for a case without the groove...and perhaps a tail shaft as well (Mr. Munroe said this problem is often caused by a worn/damaged tail shaft snap ring/bearing/groove).

 

[fishy68]

I wanted to thank you again for your responses/help.

Now the search begins for a case without the groove...and perhaps a tail shaft as well (Mr. Munroe said this problem is often caused by a worn/damaged tail shaft snap ring/bearing/groove).

Your welcome. Thanks for the update from Mr.Munroe. That makes sense as to what causes it. Good to know. Good luck finding a good case. At least big block cases are pretty easy to find.