Hi Mopartians

Got a couple of 727’s on the bench ready for rebuild.
One is a 70 440 sixpak the other a 67 s/b.

Both will see the 1320 in the near future.
So I’ve told them both (owners not trans) they are small front drum bearing (disaster) boxes.
To which they say “ it’s a Bulletproof 727” what does it matter?


Well it matters to me because I saw a guy lose his foot at Vegas raceway, with a 1970-727 drum explosion!

I raced, along with many others with ‘non rear band apply’ manual VB’s with factory cast drums.
(One guy actually said to me l “what does it matter if you run drums or disc’s, he thought I meant brakes)

So I personally will never run again without a STEEL drum...

This obviously means changing the pump housing, input shaft and stator.
Back in the day the early trans seemed to be fine, but I see a lot of damaged narrow drums and stators now...

What’s your thoughts on this Topic?

I agree with you as well. I've personally seen the results of two, and the after math of another.

I will also add that one seen, aftermath of another were protected by shields, which did nothing to protect the driver. The gas pedal in one took more force than the shield.

If the trans is 67 or newer you only need a 71 and up 2 ring stator support. No need to swap the entire pump or shaft. If it's a 66 or older it will need an input shaft and pump gears. Personally I've run the stock drums for 50 years. Never a failure. Pure racecar, mine has an aluminum drum. I've seen way more crashes and fires than drum explosions.
Doug

I have seen quite a few drum explosions. All were stock drums in a trans with either no low band apply or a stock valve body. One was in a high 13 second small block car. Stock drum with a Cheetah valve body and no blanket. His trans guy had told him it was a bomb, but he said he couldn't afford anything else. One day the car moved about 2 feet on the hit and went BANG!. Pieces came up into the car and broke his foot. He was off work for a month.

I saw my 1st 727 transmission explode on the starting line this year. Parts all over , car moved a few inches. Hole in floor, driver got out limping. About 45 minutes to hour cleanup and track prep.

Several local guys have had 727 trans explosions.

Dan Smith/ Qwkmopardan had one about 5 years ago.
He had always figured that the upgraded sprag was enough, until he had one blow up on the starting line and break his foot and put trans pieces in the windshield.

Now every trans he builds for anyone gets a billet steel drum if they are seriously racing the car.

In 2019 Cole Heilman has one blow up and broke toes on his right foot.

The billet steel drum is expensive, but so is a broken foot and it could be much worse than just a broken foot.

hi
what is the primary use for these cars drag race / street race /ect ?

what valve body configuration ?

built my personal trans in 1986 and never a prob >may others sence < std drums . hundreds of drag burn outs and 1/4 mlie passes.

narrow bushings set up not a real a prob .

stall speed ? gear ratio street tires slicks ?

torque the engines produce ?

lots of things to consider for each build !

Any dump truck trans (727) that hits the strip should have an updated drum! PERIOD! so refreshing to see mopar guys finally coming around to this necessary mod!

Naw, THIS is a dump truck trans.

Nice trans John, is that Mopar?

It’s not about ‘what is safe for oneslf’ it’s all about the safety of others!
It would be wrong of me not to tell the people I know and care about the dangers of ‘drum failure’...

What they decide is up to them...

I have just agreed today to give my newest Moparmate, a long term loan of my new Cope billet drum.
As And when I need it he can return or replace...

I feel good about this as he is family man and needs to ‘earn a crust’.

It’s hard to drive and work with a foot missing...

Or your head is covered in hot trans oil, like what happened to another Moparmate.
Not his fault, a well known UK axleman buggered his diff and broke the sprag.
The end result was burnt legs and head and a written off race car...

The guys who had to spent two cleaning the track weren’t too happy either...

The pictured trans is an Allison 750.

So it seems some of the thoughts are: I'm going to keep racing that stock drum until it blows up, takes some of my foot off and hoses up my car. Then, and only then will I up grade. After all, nothing has happened so far.

Putting in a good drum is like putting on a helmet. You hope its a waste of time.

What trans shields were being used when these explosions occurred that caused injury?
Doug

Both of them looked like the carbon fiber black stuff. But upon shattering, the Kevlar looked like a yellow ball of yarn. The one with the most injury happened about 4 years ago at an NSS race in Iowa. 65 Ply, maybe you heard about it. This racer had 1/4 plate bent up for a new trans tunnel and under the gas pedal. Really nice work for that thick of material.

I've seen a couple blow through the cf shields. I've seen a bunch blow out of trans blankets. The small block one had nothing.

From the dept of we had no idea.... early 90’s

Its seems like 2013 was a bad year for drum explosions..

Moparts is littered with pictures of Mopar and other trans explosions.

The problem isn't going away, and no matter how much protection you have, its still gonna HURT!

Either your wallet or your BODY!!!

Folks think its about speed, horsepower, bad burnout technique etc...

THIS CAN HAPPEN ANYTIME ANYWHERE IF YOU USE 'D-DRIVE' FOR BURNOUTS...
OR LET OFF THE THROTTLE AFTER A WHEELSPIN WHILST THE TRANS IS STILL IN 1ST GEAR...

The next time you engage the transmission the 'SPRAG has Broken' and then the FUN Starts...

Don't do this either???

Its called NEUTRAL DROP...

Happy Christmas to ALL Mopartians!!!

I know what I want for Christmas, SAFE DRAG RACING FOR ONE AND ALL...

So if you haven't ordered your steel BILLET drum from Santa, then I feel sorry for you...

You have been warned, if you can afford to 'run a drag-car' you certainly can afford a BILLET DRUM...

If it were up to me then I would make them MANDATORY! (but its not).

Then the prices would come down, as the demand would be HUGE!!!

But folks like to 'play with fire and hot trans oil' its all part of the fun.

Then you will be needing a lot of this if you 'luck-out'...

Where did you get your information on the 64 in the pic above - that wasn’t a neutral drop.

And you being a newby here- (or are you?) - preaching to the choir.