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Burnout without blowing up a 727

I never had a trans explode either, but when I built the new 500" Stroker I decided to make upgrades to the transmission.
It gets expensive pretty fast. Got the A&A Super Sprag, Billet steel front drum, and after noticing splines in the front planetary were cracked and a few fell out, got the steel front planetary gear too. Then the pump with modified stator support. That is in addition to replacing all the servos with dual ring billet versions, the Cope manual reverse valve body, and a bunch of other stuff like light weight sun shell and aluminum rear drum. Pretty easy to have $4K or more into a built 727.
And your list doesn't even include a transbrake..... or a converter that can handle one.
 
I never had a trans explode either, but when I built the new 500" Stroker I decided to make upgrades to the transmission.
It gets expensive pretty fast. Got the A&A Super Sprag, Billet steel front drum, and after noticing splines in the front planetary were cracked and a few fell out, got the steel front planetary gear too. Then the pump with modified stator support. That is in addition to replacing all the servos with dual ring billet versions, the Cope manual reverse valve body, and a bunch of other stuff like light weight sun shell and aluminum rear drum. Pretty easy to have $4K or more into a built 727.
Only ever built one trans with a billet servo. Low /rev servo only. It's in my street car that has a CRT LBA valve body. Did it need it? Maybe. The only reason for the LBA valve body is it had a stock drum and a shield wouldn't fit. Every other trans I've built has had stock servos. Been building hot rod and drag race 727's since the 80's. Never a servo failure. The modified stator suport can be done in about 2 minutes with a cut off wheel. The aluminum drums, aluminum clutch carrier, and lightentened sun shell do nothing for durability. Good if your trying for the ulltimate in ET. I run them all. No way I'd run a lightened sun shell with a steel drum. That billet steel drum is over 6 lbs heavier than an aluminum drum. The lightened sun shell saves about 1lb. They are both splined together and rotate as a unit. So the weight is cumulative. If you are using a LBA valve body no need for a Super Sprag either. The steel front planet with a really strong motor 750+HP or when using a trans brake is a good investment. My friend machined the sun shell in a mill.
Doug
 
On the rear servo I think the heavier retainer and billet servo isn't a bad idea.. I have taken apart one that came apart when the retainer gave way. I don't recall billet even being available back then. The servo got really messed up and was a challenge to get apart, scored the bore. But of all the ones I have been threw..just seen it once.
 
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I'm always amazed when I see this stuff!

No one knew about sprag failure back in the 80's and 90's...
I guess the sprags were still fairly new?

Now its sprag failure on every street corner!

I would NEVER use a 727 without a steel COPE front drum these days.
I would never build a trans for friends without one either...

Everyone rags their trans, it comes with the territory.
Now we know how lucky we were, 'BACK IN THE DAY'...
 
I have been following this thread but just got around to watching the video. UT is like a worm that gets in my head and irritates me.
But man that thing let go fast! About a second after he hit the gas.

Then I watched the next video about him racing Casper with bottle rocket. I don’t know anything about Casper, but if I were a betting man my money would be on him.
 
A few months ago, friends 47RE had a broken low/reverse servo.
Ultimate Converter made me a custom 9" converter. It's nice but over $1K.
The aluminum rear drum comes beveled for clearance for the 5-clutch front drum, and I was already getting all the other stuff.
This was the first build of a heavy modified 727 for me. Did the rear case vent, and a bunch of other mods too.
With all the new aftermarket parts, needed to get the shim kit to reset all the clearances.
I though of using the aluminum drum, but went with steel.
I think the only remaining stock parts are the case, rear planetary gear, input and output shafts.
Found that using the heavy duty front band strut, the offset goes towards the drum or it will hit the valve body.

As crazy as all that seems, it's nothing compared to a heavy modified 48RE for the Cummins. Easy to have over $10K into a modified one.
 
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