727 question

[Rog]

Is there any difference between a 727 that came from a 72 NewYorker with a 400 CI and one that came from an early 383 car, dont know what year. I can have either one for free. Will have it rebuilt either way. Its going in a street rod behind a 440 with around 430hp.

[rumblefish360]

Not really.

[plmczy]

Check your input shaft, earlier ones had a coarse spline and later(after 68 I believe) had fine spline shafts. most TC sold now use the fine spline shaft. I hope this helps. later shawn

[John Kunkel]

After 30+ years, it's hard to predict what you'll find inside either but, if the '72 came from a 400 2-barrel car it will need a lot of expensive internal upgrading for a performance installation.
If the early 383 was a 4-barrel it is a better candidate.
Post the numbers on the trans pan rail to ID their origin.

[plmczy]

What kind of expensive internal upgrades? I'm just curious because the 727 I'm using in my Roadrunner was out of the same car as my 383, a 69 Fury III. It had a 2 barrel carb on it. Is there any kind of literature out there to tell me what was different between 2V,4V,and high performance 727 internals? Thanks for the help. later shawn

[hotrod7043]

minor differences and the input shaft diff is way back in 63, your mp parts mgr

[hotrod7043]

Originally posted by plmczy
What kind of expensive internal upgrades? I'm just curious because the 727 I'm using in my Roadrunner was out of the same car as my 383, a 69 Fury III. It had a 2 barrel carb on it. Is there any kind of literature out there to tell me what was different between 2V,4V,and high performance 727 internals? Thanks for the help. later shawn

only real diferences are the wide 5 clutch frt drum used on 426 and 440-6 cars, and 4 pinion planets, used on hp versiaons ond 440-6 and hemi cars if you need pn,s contact me

[1972roadrunner]

i had good racing bands (disks) put into my 727 and a 5.1" second gear because my motor tore up the tranny. I rebuilt my motor and about 5 days later had my tranny done....

the tranny cost me about $700 to have it rebuilt.

[plmczy]

HotRod7043, could you e-mail me those part number's? I'd really appreciate it. hauck@digital-link.net. Thanks for the help. later shawn

[plmczy]

1972roadrunner, I built my trans myself to try and save some cash(plus the local guy won't touch them because of some problems they have) and to be able to say I did it myself. Here's what I did to mine.......

I used a Level 10 rebuild kit. includes..
5.0 kick down lever
new steels and kevlar plates
Performance band
new seals,gaskets
high flow brass filter
15 springs for under front drum clutch
pump bushing
pump bolts
A&A bolt in rear sprag
Turbo Action manual reverse valve body
I built this over the course of the winter one year(no heat in the summer kitchen,lol)and it works pretty good for a begginer. later shawn

[Tarrbabe]

I can't remember but some of the older (pre-71 or 72) didn't have the part throttle kick down like the newer ones. If you buy a shift improver kit, it makes a diffrence which model year. I'd go with the newer trans for that reason. Just thinking out loud.

[beepbeep2k1]

what is the actual difference between the stage 1, 2 & 3 trannys.
what to look for to find them, and Hp range for each.?

[hotrod7043]

dontscrew around plum crzys trans is the way for afirst time guys , otherwise i use Dynamic racing transmissions and Tct converters in n.Branford ct there stuff is great .203-315-038 they are the best as far as im concerned, turbo action is also there may be others but i havent dealt with them. they dyno evry trans, and can do your trans from street to race the right way

[John Kunkel]

Most low performance 727's out of the 2 barrel 383 and 400 had 3 clutch front drums that must be modified/replaced for at least 4 clutches. They will also have 3 pinion planetaries. This isn't an issue with me but it is to some builders who insist on no less than 4 pinions.
The '71 and later ones have a controlled load front servo that needs to be modified/replaced and most will have a low ratio front band lever that must be replaced.
Picking a core with the best internals to start with saves time and money when building a performance 727.

[Rog]

The numbers on the tranny are 4028424 on one and 3515845 on the other one. Thanks

[John Kunkel]

4028424 is from a '76-'77 440 standard performance, it will have a 4 clutch front drum and 3 pinion planetaries.
3515846 is from an early '72 400 2 barrel, it will have the 3 clutch front drum and 3 pinion planetaries.
If it were me, I'd build the '72, disassemble both and use the later front drum in the '72. If, for any reason, you want to swap planetaries, be aware that the spline on the output shaft changed in '76, the front planetary from a '76 and later won't fit a '75 or earlier output shaft and vice versa.

[plmczy]

What does the 4 pinion planetary do for performance? later shawn

[Rog]

Are you saying to put the 4 clutch front drum from the '76-77 in the 72 and stay with the 3 pinion planetaries? Wouldn't I end up with the same as the '76-77? Maybe I'm missing something.

[hotrod7043]

gee i handed out alot off thrans parts in the late 70s and early 80s and never had a tech ask for 3 discs so maybe jokn k has found the t727s kokomo is lookin for, shawn 4 pinions pinions are just the stronger planetary , durablitity my friend

[John Kunkel]

I don't ike the '73 and later 727's, just a personal preference, no logic. That's why I'd use the '72 core for building.

Many trans builders feel that the 4 gear planetary is essential for performance applications, I don't. The 4 gear didn't appear until '67, that means that all Max Wedges, Ram Hemis, '66 Street Hemis and early nitro funny cars all ran with the 3 gear units, there was no epidemic of gear failures. In fact, the weak point of the planetery gear train isn't the gear count but is the spline in the aluminum front planet carrier. It will fail before the gears, themselves, do. If you feel the need to upgrade, get a steel carrier.

Most '71 and later 727's have a controlled load kickdown band servo. This was introduced to soften the application of the band. Most builders will want to trash it and replace it with the earlier unit, that's additional expense. I merely modify the existing one at no expense. Along with the controlled load servo, lower ratio apply levers were used and need to be replaced with a higher ratio lever, added expense.

The 3 disc front clutch drum is identical to the 4 disc with the exception of the snap ring that retains the clutch pack. The 3 disc has the snap ring groove located deeper in the drum. I have a lathe so I can machine a new snap ring groove higher in the drum to allow the installation of another disc. Most shops aren't equipped to do this so they will want to replace the drum, added expense.

So, depending on who builds the trans, the later Lo-Po core can add up to more expense just to upgrade it to the earlier Hi-Po before any performance modifications are made. That's why I feel that it's better to choose a more desireable core before building, it may be cheaper than upgrading the one you have.

Here's a photo album of some of the differences in 727 parts over the years.

http://albums.photo.epson.com/j/Albu...a=13489738&pw=

[mauve66]

the year switch for the input shaft was 67 as the original tranny in my 66 wouldn't take a later convertor due to the difference in splines(teeth) on the shaft...... of course no one told me about this until after the rebuild, installation of old convertor, installation into car, wow it doesn't drive, the tear down to flip flop one of the valves put back in the valve body upside down, the purchase of a new convertor(since it was out AGAIN), wow this convertor won't go on, back to the tranny shop for the later shaft,THEN back into the car, wow listen to this........ CHIRP!!!!

[bwlizard]

The 727 I just bought from Klem Racing has part # 3681862 and serial # 44484363 any idea what kind of vehicle this was originally from and what hard parts were in it ?

[John Kunkel]

3681862 was originally installed in a '74 B or C body with a 360 2 barrel, about as low performance as they come.
4448 is the build date October 1, 1973

[Bret]

I have had a few 727s in everything from an 70 cuda to my 78 motorhome and 78 truck . All of them when first started in the morning will not fully engage in drive or reverse for a good 30 secs or so . It is clear that this is a design problem but a manageable one because all that is needed to side step the problem is to put it in neutral for a sec and the pressure pumps right up . But i would still like to know what causes this to happen and is there an easy fix .

[Tarrbabe]

I have been told that the fluid leaking back out of the converter causes that. Maybe I'm the odd one but I have never had that problem with a 727 or a 904. And yes I have had several.

[transfixleo]

Bret,
The original TF's had no Park position. Once they added it, that was ALL they did do consequently there is no converter feed in Park. That is why putting it in Neutral (that is why you check oil level in N by the way) the converter gets charged with oil (after draining down over night) and away you go.

The simple fix and big improvement is to add the TransGo Shift Kit or Reprogramming Kit. It comes with a redesigned Manual Valve and you modify the circuits to work with it and you get Full Time Converter Feed, the ability to check your oil in Park and eliminate a lot of mysterious failures including broken Converter necks.

[Bret]

Thanks for the answer. Finally after 30 years of wondering it makes sense . What would cause the broken neck on the converter though ? I have never had that happen though i have severly abused a few tf,s in my day . My current ride is a 78 3/4 ton with a 400 . It doesnt have much going on now but it will . It does have a kit in it from a previous owner and it slams reverse way to hard for me and gets second with a good thump too . I want to get more with the stock range of feel someday but dont want to detonate my mixer before then . Do i have need of worry . Im not a drager just a criuser so there is no big worry about that . And on the side to show how cruel life is . My boss told me of a 57 392 hemi in his garage that he wants to sell . I cant afford it . Life is rotten

[transfixleo]

With no Converter feed in Park it runs low on fluid after sitting, leaving the Bushing dry at times, also under heavy load conditions or even just going up hill in Reverse Converter feed gets cut off too, causing the same situation. The TransGo SK corrects those problems too.

[Bret]

Or is it lack of design . Well thanks for the info its very usefull . Keep smokin the kiddies and their weed eater propelled ricers

[beepbeep2k1]

some one with answers, yes...
transfix..
why have 2 size flex plates.? 10" and 11" for the 727 bb/sb


oh lookie there, they dropped the junior off member..... yes.