g'day all almost time to build my 727
 

well as the stallwarts may know i have built a tough street / strip 383 for my aussie built 69 vf ute ( a body pickup ) . i have had a bad run for the last 2 years , hopefully the worst is behind me now . well i need a 727 that will cop all the abuse that my heavy right foot will dish out . i have a fair idea what parts i need but there's some things that you more experienced guy's or gals may be able to help me with . there's a good chance i'll be using stock cast clutch drums or housings . are the kevlar type bands to hard on cast drums ????
what type of friction & steel plates should i use ? & yes money is a issue to some extent .
i'm using a reverse pattern full manual shifter for extra protection , but don't know what type of over run clutch i should use ???
planet gears , pump gears ect . US $1200 - $1500 is about all i can spend on parts . twice i had money to buy parts but both times the shops couldn't answer very simple questions about early & late model 727 . my box is a 68 727 . the main question was about the number of friction plates i could & couldn't use & why . then i've been told that i should only use the leased amount of plates that it takes to work :rolleyes: because they tax hp ???? mmmm so i'm not sure where to spend the money . i'd like to replace as many parts as possibal but money is the deciding factor . any guidence or advice would be most helpful . i know toad put me onto some part shops ages ago but i can't remember there name . pact racing seems to have good stuff but they couldn't tell me why i can't use there clutch plates ??? :banghead: & because i live in australia i just can't take the parts back down the road if there wrong :( .

It will be expensive How much HP does the motor have ? I would build it to Hemi specs
with the wider drum and extra clutches Maybe even a billet in and out shafts
NOT CHEAP

really that much ?
it should be 500 hp + . most people say the old 727 can cop this quite easly . i'm no expert by any means , but it's what i got & gota make do the best i can for my budget .

Hey Dead, I'm no tranny guy but I have one that is great... Paul Forte at Turbo Action in Jacksonville Florida... www.turboaction.com He will answer e-mails and is an expert on the 727's... Give him a try mate!!!!

Unless you're making over 700 hp, the stock input & output shafts are fine. You don't need to do a whole lot to it to handle 500 hp. Here's what I would use...

Bolt in overrunning clutch
Red lined frictions
Kolene steels
Red lined solid kickdown band
Kevlar low/reverse band
4.2 ratio kickdown lever
Billet rear servo
Billet rear servo retainer.
TransGo TF2 shift kit.

If you're planning to use a rev. manual VB, make sure it's one that applies the low/reverse band. The ones that don't are a ticking time bomb.

If you're doing the work yourself, you can build this set up for 500-600 USD. (This does not include the rev. manual VB)

I usually get my all my tranny parts through TSR Racing http://www.tsr-racing.com/
They're great to deal with and really know their stuff.

thanks 6pak i had good faith the old 727 would be fine for my needs without going too wild . tsr is one of the sites i looked at ages ago but forgot there name ;) . in a hurry will get back cheers guy's .

Hey Ollie! Did ya stay dry mate! Sad thing for a few of my friends. Got very wet and lost alot, but no lives, thank god! I havent heard from ya since the floods in Brisbane.

yeah mate we were ok here thanks to a new dam that was built near a place called boonah . that dam was filled in one week of it being completed :eek: bloody la nino we had 9 years of drought & now 2 years of floods poor farmers . but it's good news for us hunters :D but it's still to muddy to get out there . our place is still quite damp & soggy though . we are still getting quite regular rain ( wich is great for the day's off work with pay :D ) although around 30ish people died , they were mostly from a place called toowoomba & grantham , toowoomba is 800 meters above sea level & nobody expected the wall of water that hit those poor souls in the main st of town without warning . it took 1 1/2 day's to reach brisbane , it was funny though i was getting all my weather reports from grant in canada while i was at work , we ran next door to the hospital to watch what was happening in towoomba on the tv . thank fark for international txt messaging :rolleyes::D . ok till next time . btw hows your lil girl going scot .

I hate to sound stupid, but have you "googled" "how to build a 727"? I found a guy that posted 461 pictures on how to rebuild the 41TE trans in my Sebring. I find it hard to believe that someone hasn't done it for a performance 727!

i have watched a few but there just stocko gearboxs though . the plan was to have a go at doing it ourselves , but there's little things that would be missed along the way for sure . i want it to be as relieable & strong as i can , so it's best left to somebody who knows what there doing .

I'd google up the sprag problem--certain conditions during burnout can not only destroy the transmission, but ruin your day as well.

The consensus is you need a "bolt in sprag", and a better quality drum.

There's some great free videos on youtube:

http://www.youtube.com/watch?v=xzJhCBZ1wMY

This book is an absolute must have:

http://www.amazon.com/Torqueflite-72.../dp/1557883998

And another great help is the ATSG series of rebuild books:

http://www.atsgmiami.com/

Look around as to price though. I think I found their book cheaper on ebay than I did on their own site.

A quick Google image search on "sprag failure"

Attachment 16095

which came from here:

http://board.moparts.org/ubbthreads/...&an=0&page=996

727 explosions like the pic above are caused by after market valve bodies that don't apply the low band. A bolt in sprag is a good idea but it would not have prevented that.

Here's some good info. from John Cope from Cope Racing

There has been a lot of talk about aftermarket manual valve bodys with the low band apply feature,and for good reason. First, you should understand how the low/reverse band in Chrysler transmission works. In a stock 904 or 727, the low/reverse band is applied when the gear selector is in R / reverse and/or L / first gear, sometimes called low one.When the gear selector is in the D position and the transmisssion is in first gear, the low/reverse band is NOT applied. So, the low/reverse band does not have to be on to get first gear. When the low/reverse band is on or applied, the band is applied around the low/reverse drum. The low/reverse drum is splined to the overrunning clutch, also called the sprage.

727 low/reverse drum,low/reverse band,sprage race

When a 727 or 904 transmission is in first gear, D, or L the sprage is in the locked position. ( note: the sprage free wheels in 2nd & 3rd gear) Having the low/reverse band on will keep the sprage in the locked position under heavy or high performance loads. Now, the sprage AND the low/reverse band are working together to keep the low/reverse drum in the locked or stopped position. You can try this in your rear wheel drive mopar or your Dodge ram. Test drive the car or truck with the gear selector in D. Note the feel of the 1-2 shift, then put the gear selector in L, shift to 2, and you will feel the bands overlap. The shift will not be as quick and or firm. (note: the KD band comes on / is applied in second gear) This is the problem that aftermarket valve bodys had when making the 1-2 shift in racing transmissions. As we all know, when racing we want quick/firm shifts, if not, we would have probs with burning up bands because band over lap is having both bands on at the same time, or the timing of the bands coming on then off to make a clean and firm 1-2 shift. So what was the only solution (at the time) to make the 727 & 904 have a clean and firm 1-2 shift? Leave the low/reverse band off/unapplied in first gear. Remember, the low/reverse band does not have to be on/applied in first gear, to get first gear.
Now, by leaving the low/reverse band off, the sprage has to do all the holding of the low/reverse drum. This now makes the sprage a weak point in the 727 trans because the low/reverse band is not applied along with the sprage.

What happens to a 727 when the sprage fails? The transmission will free-wheel at 2x the eng. RPM. When this happens, and the stock steel front drum is in the transmission, the front drum will explode.


This 727 was in a 11 second bracket car,that did NOT have low band apply.
How fast are you going ?

Now that you know what can happen when having the low/reverse band off/unapplyed when running a stock steel front drum, it's like having a time bomb strapped to your car. Do you want a valve body with low band apply? I know I do.

How can the 727 sprage fail in a racing transmission ?

1. Any time the sprage is shocked, you break a U-joint, axle, or ring&pinon, it can cause sprages to fail
2. Driver error. In the heat of competition/excitement a driver could accidently nuetral-drop the transmission. I know what your thinking, I've never done that. But it could happen.
3. If the carb or ignition causes a back-fire and the car noses down and picks back up, or if you get in and out of the throttle while in first gear, you can damage the sprage.
4. If the car hooks, then the tires spin, then hooks again, the sprage can fail. And I know none of us have EVER had traction probs. (yeah, right)
5. Doing burn outs, starting in first gear is the biggest no-no of all. Burn outs should be done starting in 2nd gear and shifting into 3rd gear.
All 5 conditions are while in first gear.

How can you tell if your manual valve body does or does not have low band apply in first gear?
With the transmission in first gear and driving about 20 MPH , let out of the throttle, if the car goes to idle and the motor does not help the car slow down, (engine braking) you do NOT have low band apply in first gear. If you car slows down and the motor helps slow the car down, you DO have low band apply in first gear. Note: If you know you have a valve body with low band apply in first gear and your car does not have engine braking, your low reverse band may be out of adjustment or you may have a broken band strut, or you have a cracked low reverse pistion. Checkng to see if your low band apply is working ,you can test this by checking the engine braking in first gear.

I must let you know that Rick from A&A transmission is the leader in low band apply technology. All CRT transmissions with manual valve bodys and trans-brakes, come with the low-band technology.
CRT is a authorized A&A dealer.

Dead, last really strong tranny I built was after I read an article on Level 10 Transmission co out of NJ US I think. I got some of thier parts, and it was the best move I'd ever made on a 727. You already have a manual body, so that will limit what you get from them, but I can't reccommend them highly enough.

727 is about the easiest automatic tranny there is to build, jump in there and put it together. I don't have any doubt at all that you can do it, and you're doing the right thing.... gathering information in advance of the build, not just taking it apart and going "I don't think I need THIS part" as it goes flying over your shoulder.

You're right I should've mentioned that. The point I was trying to make is to do some research and find out what's out there. Lots and lots of stuff result with a Google search.

I'll be rebuilding a spare 727 later

well guy's i am aware of sprag & hitting free rev problems . & burn outs & hard accelerating is everyday diving for me , let alone the drag strip .
from the fan & balancer -to the strengthened diff everything is good & solid . i want the 727 to be the same nice & strong . that was awesome about the low band , i'll read it again at a better time . thanks heaps for the feed back .

ok so burnouts are fine if started in 2nd , & i need to find a reverse pattern shifter with a low band ingaged in 1 gear & also a bolt in sprag . i know a billet steel front drum would be handy but the extra $600 + is just getting a bit much , although if i can at the time i'd love to get it .
i think the bolt in sprag + the reverse pattern shifter with low band apply should just about solve the problem from happening in the first place . concidering i have new yukon axles , new d/locker & strange c/molly yokes it should be a sound set up . i'd like to spend that $600 or more on brakes :) .

https://www.coperacingtrans.com/inde...d42ce41f713a9c
http://www.aandatrans.com/Department...ve-Bodies.aspx

awesome both saved as favorites .
oh yeah i'm getting keen to hear this thing rumble , i still have alot of cash to spend to get this ute set up how i'd like it :(:(:( . the poor old girl has a few cracks in the chassie that have been welded with over lapping arc welded plate steel . :(:(:( so i need a chassie sleeve & it would be a good idear to get a 1/2 roll cage made up also to help stiffen her up & to cover me into the 10 sec bracket if i ever want to use nitrous .