727 Build for Mid-10s

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CudaFactHackJob said:
I just didn't know where to start; so much wrong in that sentence. So..you want to pay a machine shop to grind the top plate rather than spend the same amount for the thin reds? Did somebody really mention the piston? And somebody said the drum was "designed" for five plates? Check out the description in eBay item number:
140082616713
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The company I bought the billet steel (aftermarket) drum from said it was designed for 5 stock thickness clutch discs (w/ stock piston), which is what I bought. Turns out I only have .018" in that configuration. **** happens I guess. So, to get my extra .070", I can either replace two of my frictions with thins, or use a thinner pressure plate/snap ring, or a combination of those. What do you recommend? I just assume use the frictions I've got and spend $20 on a thinner pressure plate - as mentioned above from A&A. Seems like a no brainer to me. What would you do?
 
mopowers said:
I'm in luck! Turns out A&A sells pressures in various thicknesses for only $20. They've got one that's .207" as opposed to the stock .275". That'll leave me with .086" clearance in theory, which is right in the 80-95 thou range CRT recommended.

Another minor victory today - With some creative grinding and my drill press, I was able to clearance and drill the case to use all 6 bolts on the Ultimate sprag. No costly jig necessary. On to assembly...

View attachment 1715501510
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One other suggestion since you mentioned A&A trans.
They also sell non standard thickness steels to help dial in the clutch pak clearance.
 
The idea is to strengthen the direct clutch with more surface area. That's just another reason why I said to pass on that kit. If you can fit five thicks; then you can fit six thins. And that can be done wit a stock drum.
 
CudaFactHackJob said:
The idea is to strengthen the direct clutch with more surface area. That's just another reason why I said to pass on that kit. If you can fit five thicks; then you can fit six thins. And that can be done wit a stock drum.
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I get it, but I already have the parts. Sorry, but I'm not going to toss them in the trash.
 
I didn't say to toss them in the trash. Where did you get such an idea? Do you want to build it right or not? You're just wasting money on unnecessary parts and to end up with a trans about 25% weaker than what's available to you for very little money.
 
CudaFactHackJob said:
I didn't say to toss them in the trash. Where did you get such an idea? Do you want to build it right or not? You're just wasting money on unnecessary parts and to end up with a trans about 25% weaker than what's available to you for very little money.
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For my build, 5 clutches will work just fine. Did I mention that's what was recommended to me by CRT? I think John knows a little about these transmissions.

Even if I bought 6 new thin frictions, the clearance would still be too tight and require adjusting, so the $20 I'm 'wasting' on a thinner pressure plate would still be required.
 
I didn't say $20 on a thinner top plate was a waste. I have bought them myself. I don't appreciate when people put words in my mouth. I responded to having the plate machined. A machine shop I know would charge a lot more than $20 to do that process. I'm responding on this thread to guide folks who want the best out of their trans for the least amount of expense; most bang for their buck. I recommended against $140 for that rebuild kit because it included thick frictions; for one reason. Now you'll have five frictions; that's great, but I think most builders wouldn't want to spend near that much money to get there. Anybody can put five frictions in a stock drum. Five red eagles, stock steels, and usually a stock top plate; or the $20 one, and that takes care of the weakest point on the 727. That direct drum mod and a shift kit and it's good for 500 horse easy. I just don't want folks thinking that they have to spend a ton of cash to do it right. Did you measure the direct clutch clearance from the top of the wave?
 
CudaFactHackJob said:
I didn't say $20 on a thinner top plate was a waste. I have bought them myself. I don't appreciate when people put words in my mouth. I responded to having the plate machined. A machine shop I know would charge a lot more than $20 to do that process. I'm responding on this thread to guide folks who want the best out of their trans for the least amount of expense; most bang for their buck. I recommended against $140 for that rebuild kit because it included thick frictions; for one reason. Now you'll have five frictions; that's great, but I think most builders wouldn't want to spend near that much money to get there. Anybody can put five frictions in a stock drum. Five red eagles, stock steels, and usually a stock top plate; or the $20 one, and that takes care of the weakest point on the 727. That direct drum mod and a shift kit and it's good for 500 horse easy. I just don't want folks thinking that they have to spend a ton of cash to do it right. Did you measure the direct clutch clearance from the top of the wave?
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Who said I bought a $140 rebuild kit? I have a flat snap ring, as mentioned in post 117. I think you may be getting this thread mixed with another. I didn't buy a billet steel drum to use 5 frictions. I bought it for strength. The piece of mind is well worth it to me.

btw- got the planetary drive assembled today. Clearance was at .017".
 
mopowers said:
Who said I bought a $140 rebuild kit? I have a flat snap ring, as mentioned in post 117. I think you may be getting this thread mixed with another. I didn't buy a billet steel drum to use 5 frictions. I bought it for strength. The piece of mind is well worth it to me.

btw- got the planetary drive assembled today. Clearance was at .017".
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That drum will not blow up. Peace of mind indeed. I have never seen any direct comparisons,and I understand that the thinner clutches give more surface area and holding ability, but it seems to me that for longevity, five thicker clutches would last longer before the friction material wears down to the steels. The piston would just advance further out as the clutches wear down over time, but the thinner ones have much less material before they get down to the steel. Hmmm.
 
mopowers said:
For my build, 5 clutches will work just fine. Did I mention that's what was recommended to me by CRT? I think John knows a little about these transmissions.

Even if I bought 6 new thin frictions, the clearance would still be too tight and require adjusting, so the $20 I'm 'wasting' on a thinner pressure plate would still be required.
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Keep in mind there is more than one way to thin the pressure plate.
The easy and cheap way is to throw it on a surface grinder and grind the entire plate. The other and more expensive way is to only thin the plate in the area wear the snap ring fits. A step grind which would require more setup time in the machine shop. Some builders prefer this step groove to better maintain the strength of the pressure plate so it cannot bow out.
 
mopowers said:
Who said I bought a $140 rebuild kit? I have a flat snap ring, as mentioned in post 117. I think you may be getting this thread mixed with another. I didn't buy a billet steel drum to use 5 frictions. I bought it for strength. The piece of mind is well worth it to me.

btw- got the planetary drive assembled today. Clearance was at .017".
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I didn't say that you bought the $140 kit. You mentioned it and I advised against it because, for one; it has thicker direct frictions; which I feel is just a cheap way to sell high performance kits to folks who can't think outside the box; and are content to just, "slap a kit in it". I asked about the direct clutch clearance and you said that you already specified a flat snap ring in post #117, but the word "FLAT" is nowhere in your post #117. If you really had specified a flat snap ring I would have advised against it because it will give you a harsh reverse engagement. I am a very careful reader and I have excellent comprehension skills as well.
 
Duane said:
That drum will not blow up. Peace of mind indeed. I have never seen any direct comparisons,and I understand that the thinner clutches give more surface area and holding ability, but it seems to me that for longevity, five thicker clutches would last longer before the friction material wears down to the steels. The piston would just advance further out as the clutches wear down over time, but the thinner ones have much less material before they get down to the steel. Hmmm.
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That makes perfect sense to me. Maybe that's why I was recommended to use 5 thicks. I didn't care to ask at the time.

Duane said:
Keep in mind there is more than one way to thin the pressure plate.
The easy and cheap way is to throw it on a surface grinder and grind the entire plate. The other and more expensive way is to only thin the plate in the area wear the snap ring fits. A step grind which would require more setup time in the machine shop. Some builders prefer this step groove to better maintain the strength of the pressure plate so it cannot bow out.
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Thankfully I don't need a machinist now that I found out several companies sell thinner pressure plates. After that one arrives, I think I'll have everything I need. This thing's definitely been a learning experience. Thanks for your help!
 
See, you guys, this is how bogus information gets started. If you would at least take the time to measure the steel part of the frictions, you'd see a difference in the thickness between the forward and direct. It's easily noticeable when you put an eyeball on it. And the difference of the thickness of the friction material is about .006. But it doesn't matter, because the difference isn't enough to even consider asfaras wear capability; which shouldn't be a consideration anyway, because automatic transmission frictions are not designed to wear at all. If the friction material wears off, then your 2-3 shift should be loose. If it doesn't loosen up, creating a 2-3 spin-up, then that means that your shift had too much overlap to begin with; which is what wore down your clutch; and burnt the band. If it was acceptable for a clutch to wear, then why is the initial clearance so critical? Think about it. On top of all this, a stack of six thins with six steels is a least .035 thinner than a stack of five thicks with five steels. Please measure from now on; assumptions just spread incorrect information.
 
CudaFactHackJob said:
See, you guys, this is how bogus information gets started. If you would at least take the time to measure the steel part of the frictions, you'd see a difference in the thickness between the forward and direct. It's easily noticeable when you put an eyeball on it. And the difference of the thickness of the friction material is about .006. But it doesn't matter, because the difference isn't enough to even consider asfaras wear capability; which shouldn't be a consideration anyway, because automatic transmission frictions are not designed to wear at all. If the friction material wears off, then your 2-3 shift should be loose. If it doesn't loosen up, creating a 2-3 spin-up, then that means that your shift had too much overlap to begin with; which is what wore down your clutch; and burnt the band. If it was acceptable for a clutch to wear, then why is the initial clearance so critical? Think about it. On top of all this, a stack of six thins with six steels is a least .035 thinner than a stack of five thicks with five steels. Please measure from now on; assumptions just spread incorrect information.
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When you say that you put thinner clutches in the front drum, are you using rear clutches in the front? Is that what you are referring to?
 
No, they're not rear/forward clutches. They're .062 Red Eagles that can be used in either location. Stock forward clutches can't be installed in the direct drum because they can't take the heat.
 
CudaFactHackJob said:
No, they're not rear/forward clutches. They're .062 Red Eagles that can be used in either location. Stock forward clutches can't be installed in the direct drum because they can't take the heat.
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Yes that's what I understand as well. But are you saying that those thinner red eagles that the steel part is thinner?
I put 5 red eagle thins in my 4 clutch aluminum drum 904.
I did not measure the thickness of the steel part, but to my eye they look like a good amount of the reduced thickness is because they have less friction material. But I never actually measured the thickness of the steel part compared to a thick clutch.
 
Yes, the steel part of the .062 friction disc is noticeably a lot thinner on the Red eagles. The difference in the friction thickness is only .006. I only buy the .062 smooth (non-grooved) frictions. I have some thicker smooth and grooved and thin grooved; all sent to me by mistake. I'll use the thick smooth to adjust clearance. The grooved ones will go into a stock build just to get rid of them. Oh, and on the thin top plate, just use a lower forward plate and grind off the ridge.
 
Alright guys, I had a few minutes to mess around with this thing today and had a minor setback. I went to install the rear band and drum and I can get the rear band strut it. I can without the drum in place (barely), but then the drum won't fit. The only non-stock pieces I've got are the band and the billet rear servo. The strut is stock (I believe) and measures 1.32". Is it common to have to take .25" off the stock strut to make it fit? Otherwise, could I have the assembly installed wrong? Could I have received the wrong band?

Thanks a lot. I know these are stupid questions.

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Make sure the top of the band is locked into the strut strap and back off the adjuster completely. Then put the drum in. Did you replace the o-ring on the servo lever shaft?
 
CudaFactHackJob said:
Make sure the top of the band is locked into the strut strap and back off the adjuster completely. Then put the drum in. Did you replace the o-ring on the servo lever shaft?
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Thank you. I tried that as well and it's too snug to install the drum. Top picture is with the strut installed and screw completely taken out. Looks like the strut need a slight shave. Is this common???

Yes, the shaft has a new o-ring.

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Like I said, make sure the top of the band is locked into the strut strap. Did you compare all the new parts to the old? There were changes thru the years.
 
Everything is fully seated. I discovered the problem though. The new band has thicker lugs - by about 3/16" per side. Apparently, I need one with narrower lugs. The company I bought the bands from is sending the correct one.

It's weird that Chrysler would use two different versions for the same yr, according the trans company the bands came from. Sounds like the narrow lug versions are an oddity, but not uncommon. I can only assume the strut is longer than the ones used with the more common large lug version. Otherwise, I'd find it hard to believe that Chrysler would make two different length linkage arms. Oh well, at least the problem is being fixed.
 
Running changes are common in all automatics; many have several different variations out there at the same time. Folks bring me several transs and want me to put all the best parts into one; not always doable.
 
It's amazing how much easier things go together with the right parts. TSR 2nd day'd the correct band to me and it fits just like it should. Got the gear train/output shaft installed. Almost there!

Here's a picture of the small difference in lugs. The difference is only ~3/16" per side, but it's enough to mean the difference between working and not working. I'm still thinking shortening the strut would have worked.

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I switch bands around a lot; weld onto them, make struts; especially for the old iron cruisomatics. Just have to watch the heat.
 
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