Tf 727 modify or not

[bcuda1$3$]

Barracuda 318 2 barrel/727. Recently had been rebuilding the 727 with a basic street kit/shift kit.

My transmission has 9 engagement springs for the clutches. Also has 4frictions and 3 rear.

So I’ve been reading about adding more springs to eliminate the 2-3 overlap. Btw I’ve never driven this trans, and it isn’t known to have this problem, it’s just something I’ve read.

So question..should I leave well enough alone put the 9 springs back in along with 4 friction clutches?

And/ or add the Dorman 555-115 freeze plug and drill it. I have read people drilled anywhere from .90” to .150” ?

My shift kit didn’t come with said restrictor. It was just heavy duty springs added. Drilled holes in valve plate and one through body. And the few servo rings.

Anyway is it a worthwhile mod or just leave well enough alone?

 

[Oldmanmopar]

I had the same problem with my Duster. talked to A&A at Carlisle and he said its the valve body leaking when hot. Here is two videos Cold and hot. Listen to the difference going to drive. Car was going 10.60's shifting a 8000 through mufflers.

Cold


Hot

 

[Plymouth 65]

Damn, that Duster rips. Launch looks great, very well done! 65

 

[Murray]

For street driving all that's needed is a quality rebuild and shift kit.

 

[AJ/FormS]

For street driving all that's needed is a quality rebuild and shift kit.

and a 2800 convertor,
and a semi-auto shifter that you can hold to say 5000.
and you may need a governor tune-up
But if you want to hit 5000, you'll probably need some better valve springs.
Why 5000?
Cuz on the 1>2 shift from 5000 the Rs will fall to 2950, putting your 318 350 rpm up the modest power-curve, and at least keeping up with the six-speed 4-banger in the next lane.

a 2800, for a 2-bbl street car?
Yes; Especially, for a 2bbl street machine with hiway gears. That convertor will turn her into a pretty good ripper off the line! But in this application, off the line to 20 mph is mostly all it's good for. But, if you think about it, that's a lot.

 

[transman]

I guess if it's just for street use, as Murray said to just give it a quality rebuild, a shift kit and a rebuilt converter. A stock stall (appx. 1900 -2200 stall) 67-77 318 converter should work just fine for you. If its performance you're looking for, then that's an other thing. Your posting doesn't mention anything about this though.

 

[71Demon528]

Barracuda 318 2 barrel/727. Recently had been rebuilding the 727 with a basic street kit/shift kit.

My transmission has 9 engagement springs for the clutches. Also has 4frictions and 3 rear.

So I’ve been reading about adding more springs to eliminate the 2-3 overlap. Btw I’ve never driven this trans, and it isn’t known to have this problem, it’s just something I’ve read.

So question..should I leave well enough alone put the 9 springs back in along with 4 friction clutches?

And/ or add the Dorman 555-115 freeze plug and drill it. I have read people drilled anywhere from .90” to .150” ?

My shift kit didn’t come with said restrictor. It was just heavy duty springs added. Drilled holes in valve plate and one through body. And the few servo rings.

Anyway is it a worthwhile mod or just leave well enough alone?

View attachment 1716311519

View attachment 1716311520

As far as how many springs to put in the high clutch drum, that is going to depend on a few things.

1. How much pressure you will have the valve body turned up to
2. How many clutches and how much clearance you will have
3. Kickdown servo style (early 2 spring model, or late 1 spring model)
4. Second gear band lever ratio

Yes you’re correct that by adding more return springs to the high gear clutch drum, you will help the 2-3 overlap…BUT….you can also create a shift flare by adding too many if you are not careful matching the above listed pieces appropriately.

Typically, I run 15 springs in the high gear drum. But I’m using mainly reverse manual valve bodies (pressure is increased compared to a stock or shift kit valve body), 5 clutches with .060-.075 clearance, 4.2 kickdown lever, and a dual spring early model servo.

In a recent build, with an automatic shift valve body from A&A, with a late model servo (with heavy duty single spring), 5 clutches, .070” clearance, 4.2 kickdown lever, I put 12 springs in the high gear drum. That is behind a well built 340 in a Street driven and pounded Dart.

For your application since you only intend to do a shift kit and rebuild the trans, I would probably stick with 9-10 return springs.