727 modification/rebuild

[Hot_Rodder]

After speaking with CRT about my 727 TF, we've determined that it's a '66 - '70 year tranny (there's a small plate covering the vent hole at the top of the pump... Anyway, this tranny is more or less shot with all the slippage. I will be rebuilding this tranny for street use, and it must retain it's automatic shifting capabilities. The motor that I'm in the process of building will be around 600 - 650 hp and around 650 ft/lbs torque. I'm thinking about getting the CRT rebuild kit. Though I'm not sure if the kit #727-HP or #727-RMAX will be right for this app. Any ideas? I will be running a custom torque converter, and do plan on running a transmission kit for a firm shift. Also, an aluminum deep transmission pan kit will be used too. Any input?

[mauve66]

you can also use a late model truck trans pan which is usually 1-2 inches deeper than the common aluminum ones but it won't have the drain hole unless you put it in

[charger_mike75]

I rebuilt both 727's I have in my truck and charger with tci kits, you get the shift kit in their kits as well

[lisiecki1]

the tci kits are good.......I bought all my stuff individually and built mine.....alto clutches, kolene steels, kevlar bands, bolt in sprague, and transgo stage 3 valve body kit (full manual-reverse).........basically I built a solid 800 horse trans for less than 600 bucks........

[Hot_Rodder]

Though I am planning on keeping my factory valve body (as I said above, I am wanting to keep the automatic shifting ability of the auto tranny for the street), I'm guessing this is the kit that you all are referring too? http://www.summitracing.com/parts/TCI-128800/
What about one of these too? http://www.summitracing.com/parts/DCC-4529023AB/ I had this on my '69 I used to have... Course I had a CRT rebuild kit put in, and a B&M transpack, plus a new PTC 11" torque converter....
Am I leaving anything out?

[lisiecki1]

if you're going to buy "parts" then I'll look up some good items to have when i get home tonight....I rebuild my trans with a modification handbook specifically for the 727.  The tci kit is what you need, although it doesn't specify what the parts are i.e. alto clutches, kolene steels, etc.....you want to get a bolt in sprague also, available from jegs or summit......and the transgo stage 3 kit i was talking about has 3 stages in one box so you can go mild to wild depending on what you want to do, if I remember the stages correctly, I'm thinking you'd want to go stage 2-which is a cross between keeping your automatic for normal driving and also having the ability to manually shift.

Let me know if you want me to look up some good-to-have parts for your transmission build.  I can also give you some old "racer tech" secrets that I got out of the book I bought that help you get more fluid flow to the sprague and things of that nature.

Randy

[Hot_Rodder]

Yeah, I was hoping that since Summit doesn't seem to list the contents of the kit, that the companies website would, but it doesn't, figures.... Anyway, the 69 I used to have, the kit that I bought had the Koleen steels, kevlar bands, 5.0 arm, flat washer, Allomatic red racing clutches, and a bunch of other parts. I also ran a brass filter, and as I said above, the B&M transpack (stage 2). That tranny pretty much had no slippage, shifter very hard at certain rpm's... I don't think it was ever adjusted properly, but since the car is no longer with me, it doesn't matter. I still find it funny that the guy who bought the car from me said that it was shifting way to hard for his liking, despite everything that I explained to him, lol. I am open to numerous options and ideas that will help my tranny survive behind this motor.

[lisiecki1]

I'll be glad to help as much as I can.....I'll pull the book out tonight when I get home and let you know what they recommend for the lever, I'll also give you the title and publisher info for the book, it really came in handy....I know the 5.0 ratio is a good one, but I can't remember if that one is the best for the application.....I know they recommend different lever's for different builds, I believe I have the 4.8 in mine, but I'm not positive.  If we get really deep into this I'll pm you my phone number

[Hot_Rodder]

I'll be glad to help as much as I can.....I'll pull the book out tonight when I get home and let you know what they recommend for the lever, I'll also give you the title and publisher info for the book, it really came in handy....I know the 5.0 ratio is a good one, but I can't remember if that one is the best for the application.....I know they recommend different lever's for different builds, I believe I have the 4.8 in mine, but I'm not positive.  If we get really deep into this I'll pm you my phone number

Sounds good to me. On that 727 in my old 69, I asked a similar question, but it was behind a fairly stock 440.... I ended up talking to a few folks about that 727 build, and CRT used to be on the site back then, now I've not seen anything from them on the site, course it may have been the old site.... Anyway, I figure I'll look into possibly doing this build myself, though it will be the first time I've built one.... The 727 is supposed to be one of the easiest that I've heard of to build...

[John_Kunkel]

The TCI 128800 kit is overpriced but, to its credit, it does include a reprogramming kit but it's not as good as the TransGo TF-2. You would be better off purchasing the individual parts from Makco, they're equal quality and cheaper.

http://www.bulkpart.com

Whenever anybody mentions building a 727 the first things recommended are a bolt-in sprag and a 5.0 lever neither of which is really needed. If the sprag is in serviceable condition you're better off leaving it in place, avoid the 5.0 lever and use a 4.2 or 3.8 instead.

I would recommend you get a copy of Carl Munroe's 727 book before making any decisions, lots of good info and tips.

[Runner]

john,  what do you think about kevlar bands?

[Hot_Rodder]

John, thanks for the info and the references, I will try and hunt that book down locally. As for the 5.0 lever, I've been hearing more and more to try and avoid it for street apps basically, and try to stick with the 4.2 (or so) lever. I know I am wanting a firm shift, I personally like the firm shifts (possibly more than some, lol), and hate the thought of a wimpy shift (hope I don't offend anyone by that statement) in a muscle car (esp the thought of that nice smooth confy shift creating that nice friction...). Anyways...

Runner, though I didn't really run the tranny enough for a long term basis of information, I found no problem with the Kevlar bands that I was running in it.

[Hot_Rodder]

The TCI 128800 kit is overpriced but, to its credit, it does include a reprogramming kit but it's not as good as the TransGo TF-2. You would be better off purchasing the individual parts from Makco, they're equal quality and cheaper.

http://www.bulkpart.com

Whenever anybody mentions building a 727 the first things recommended are a bolt-in sprag and a 5.0 lever neither of which is really needed. If the sprag is in serviceable condition you're better off leaving it in place, avoid the 5.0 lever and use a 4.2 or 3.8 instead.

I would recommend you get a copy of Carl Munroe's 727 book before making any decisions, lots of good info and tips.

This is the direct link (or so I hope) for their 727 parts.... http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=A727

[John_Kunkel]

john,  what do you think about kevlar bands?

Not much, I prefer the red-lined bands....opinions vary.

[Hot_Rodder]

So, what would be the best route to go for this tranny?

[lisiecki1]

The TCI 128800 kit is overpriced but, to its credit, it does include a reprogramming kit but it's not as good as the TransGo TF-2. You would be better off purchasing the individual parts from Makco, they're equal quality and cheaper.

http://www.bulkpart.com

Whenever anybody mentions building a 727 the first things recommended are a bolt-in sprag and a 5.0 lever neither of which is really needed. If the sprag is in serviceable condition you're better off leaving it in place, avoid the 5.0 lever and use a 4.2 or 3.8 instead.

I would recommend you get a copy of Carl Munroe's 727 book before making any decisions, lots of good info and tips.

600+ horsepower and you don't think a bolt in sprague is needed?  why?

Sounds good to me. On that 727 in my old 69, I asked a similar question, but it was behind a fairly stock 440.... I ended up talking to a few folks about that 727 build, and CRT used to be on the site back then, now I've not seen anything from them on the site, course it may have been the old site.... Anyway, I figure I'll look into possibly doing this build myself, though it will be the first time I've built one.... The 727 is supposed to be one of the easiest that I've heard of to build...

The book is Torqueflight A-727 Transmission Handbook, published by HP Books, written by Carl H. Munroe.  I got my copy from ebay.  I'm running the 4.2 lever in my trans.

I was originally going to have John Cope build mine, but decided to give it a shot myself, and have built many transmissions since....even some front wheel drive honda stuff.....that was interesting.

If you're going to keep the original equipment steel drums Kevlar bands will work for you.  They are a little more coarse than other options.  The Red Racing bands are good stuff and not as hard on your drums as the kevlar while still giving you great holding ability.  If you switch to Aluminum drums, Red Racing lined bands are the way to go.

With the amount of horsepower you're building for you might want to put in a 4 gear planetary.

Also, just a really good visual go to

http://books.google.com/books?id=IjnczMjW46QC&pg=PA176&lpg=PA176&dq=727+overrunning+clutch+failure&source=bl&ots=1nwyRz2eSH&sig=jCujbW2js23p2jEUkyLhR-4nK9I&hl=en&ei=otBOStiHG5WYtgesi-SgBA&sa=X&oi=book_result&ct=result&resnum=2


to see one possible outcome of a rear overrunning clutch (sprague) failure.

[Hot_Rodder]

hmmm.... well.... I guess I could say something about that tranny in that pic, and that would be..... OUCH.

I think the 4.2 lever would be the better choice over the 5.0 lever for this street app. If the red bands would be the better route, then I'll go with those instead of the Kevlar bands, after all this tranny will need to last, not like I have another one just sitting around in case this one decides to go out, lol. I've heard about running the planetary that has more gears, been a little while since, so I can't remember what the outcome was, but I think I was hearing something about a 5 gear or so.... Could be mistaken though... Since I don't have my tranny take apart yet, I don't know what all parts are bad and which ones are good, I do know all the normal wear parts I want to replace with stronger parts for the added power from the motor. On that '69 I want to say that the drum was shot, and there was a bunch of other stuff wrong with it... I bought the tranny, previous owner had "rebuilt it" but couldn't get it straightened out.... The tranny was slipping some, and the reverse didn't work, great. In the end, I burned that sucker up to the point where it wouldn't pull anymore (trying to get it to where I had to rebuild it, seemed to have worked....).... This tranny that I have now for this '72 wouldn't hardly move the car at all. Now, yes the tires were kinda flat.... The motor wasn't running all that great.... Brakes were not locked up, I had to pull the car to the house from about a half mile from here.... Bumpy ride as you might could imagine... Anyway, when I put the car in gear, I could feel the tranny engage, but when I gave the motor more throttle, the tranny tried to pull, but just didn't have enough to move the car... This was in both reverse and forward gears... On the other hand, park and neutral seemed to work fine, car didn't go anywhere, lol.

[John_Kunkel]

600+ horsepower and you don't think a bolt in sprague is needed?  why?

The bolt-in sprag only prevents one type of failure, the type where the outer cam ring spins in the case. This type of failure is less common than the failure of the internal elements. Below is a pic of a failed bolt-in sprag with the end of the bolts clearly visible.

Instead of messing with the sprag, it's my opinion that the money would be better spent on a LBA valve body or a billet drum or, better yet, both.

I also disagree on the need for a 4-pinion planetary, the weak point in the planetaries is the spline in the aluminum front planet carrier, not the pinion count. A steel 3-pinion is less failure prone than a 4-pinion aluminum.

[lisiecki1]

i was under the impression that you could buy 4 pinion steel planetaries?  I agree that a bolt in sprague only helps against one type of failure, but with the amount of horsepower he's planning on putting out I would consider it relatively "cheap" insurance.  I also agree on your points about the valve body and the billet drum.  I guess the important thing here is finding out the budget for this transmission build.

[Hot_Rodder]

Sorry about my absence, my computer lost it's internet connection, luckily after running virus scan three times, deleting a bunch of stuff, it let me back on, but after now, there's no telling for sure.... Ouch. Anyway, I hate setting a budget amount, always have, and probably always will. On that note, I will say this, I'm not trying to build a full blown race tranny, though this tranny will behind a motor producing anywhere from 600 - 650 hp and roughly some 650 ft/lbs torque, it will need to stand up to this motor, the tranny must also maintain it's automatic capabilities, so no manual valve body. I don't think a billet drum, ect would be needed, if it is, then so be it. I picked up a 727 tranny book, went through it some, and well.... Though I've been told that this is one of the easiest tranny's to rebuild, the book makes it look quite difficult, esp since I don't have the specialty tools that appears to be required for an overhaul. Here's what I am wanting to do, obviously I want to replace any of the normal wear items, and I also want to run an aluminum deep tranny pan and a brass high flow filter. I will be using a stack plate tranny cooler also. Instead of running the Kevlar bands like I did this time, I'm figuring on running the red bands. Instead of running the 5.0 lever, I'm thinking the 4.2 will probably be better for this application. A shift kit will be used, stage 2 setting I feel is my best bet. I do want to go back with the Koleen steels, and red clutches. This is what I feel is a good start on things that I need to get to rebuild this tranny to a street performance tranny keeping it's auto capabilities, and to be able to handle the high power of the motor. Hopefully I'll be able to get back online later on to see what folks have to say.....

[lisiecki1]

At first look, it can be quite ominous, however once you get it disassembled you'll be very familiar with the parts and have a lot better understanding of what's what.    For what its worth, I built all of the tools needed to do my first rebuild in my shop.

[Hot_Rodder]

I know I've taken a 727 TF apart to a point in the past, but never got around to rebuilding it.... I never did get the tail shaft taken apart....But the rest of it I took apart.... Now that I think about it, I might still have that tail shaft, but the rest of it was picked up when the '69 sold, guy was supposed to get all of that tranny, guess he either didn't want the tail shaft end up it or looked over it, don't know, will have to check that out.... As for making the tools, well, I've rigged up some stuff in the past, but for some of these tools, will have to check into it...

[lisiecki1]

If there's any tools that youre not sure how to make I'd be glad to tell you what I did to accomplish the needed goals when I was doing mine