Burnout without blowing up a 727

[R413]

Disagreed with starting out in 2nd at the track.
You end up actually starting out in 1st, without applying the band. Like starting in drive.
Always start in 1st with a fully automatic 727.

I forgot to mention the manual valve body

 

[64BEL]

OOPS!

 

[65wgn440]

Then they lay under the 4300lb car with only a floor jack... Dumbasses

Yeah, the jackass is in such a hurry to get some video of the shrapnel under the car, so he can get some more "YouTube gold", that he can't take the time to grab a jack stand when he brings out the jack ! How famous he would be if that jack failed and his customer was crushed. Then the idiot bounces the jack handle off the side of the dude's car after they roll car back. People actually watch this clown ??

 

[Virg464]

I'm sure some of you have seen an or heard about an episode of Uncle Tony's Garage (not that i watch it) where he's insisting some guy do a burnout. Anyways, the guy blows up the transmission and is lucky to still have his feet. How do you avoid blowing a 727 by doing a burnout? I saw some talk about not letting off until it shifts to second?

Glad you asked the question, I had no idea that would happen and I'm in the process of putting a car together that I don't to break the first time at the track.

 

[33 IMP]

My 62 has had something blow up (a little I guess. ). I ran across a guy who said he used to own it (even though I bought it from GTX John.). He said if I ever pulled the rubber mat up, I'd find a trans tunnel patch.



He was right.

 

[fesser]

You guys are freaking me out a bit. Is this mostly relevant to huge horsepower, sticky tires, drag strip situations? I can't think of how many burnouts I did back in the day (on the street) where I lifted before hitting second. Never saw a blown up 727 in person.

 

[sabre67]

 

[OKDart]

This video by Cope Racing explains it very well, and with visual aids:





Here is a previous discussion of that video:

Interesting 727 info - exploding transmissions - John Cope




.

 

[493 Mike]

Those TA instructions seem rather confusing?
Mike

 

[Curiousyellow71]

Those TA instructions seem rather confusing?
Mike

I think the second part is a bit confusing..TA saying its ok to do a full power burnout but not ok the let up on dry pavement. The engine has to decelerate at some point in either case. I always assumed the quick jerk off the gas when it's running rpms and the tires grab (in first) the shock can kill the sprag coming from the tires. Cope exploded his somehow hitting reverse accidently. The sprag obviously can't be taken out if it is not doing anything. 904s and 998s already have a bolt in sprag and less mass. It's the combination on the 727 large diameter cast front drum and sprag that is not bolted that require upgrades for serious performance. A car with street tires and a mild motor it is possible to take out the sprag clutch...but there is a huge difference taking 700hp and 14x32s slicks at the track while doing a improper burnout vs a street 275 radial and 450hp on a highway no rubber. Copes videos are the best I have seen.

 

[dusterkid]

I've heard of this happening at the track a few times thru the years. Typically there's an underlaying issue that causing this. Either a broken rear gear, u-joint, wheel hop etc. I've been running 727's since 2003, my dad been around them all his life. Knock on wood we haven't had any issues. We've never had a transbrake or anything super fancy or special in ours trans. Our cars aren't super fast either, Mid 10s and slower. I've been running TA valve body probably for 15 years or more. How I do my burnout is I roll thru the water (don't spin, just drive thru). Pump the brake 3 times, hold the line lock and mat the gas about 1/2-3/4 throttle, as soon as my foot is there I grab 2nd than drive and than release the line lock. I keep the RPMs under 6K, but I've always start out in 1st.

 

[Ceedawg]

On and off for 55 years racing, first, second, third, drive car out of water letting off the gas as car rolls out. Put back in first, under power, holding the brakes, roll forward a few feet to set sprag. IF the sprag is bad you’ll feel it then. Go race. If ANYTHING breaks in driveline fix the sprag!
If you know nothing about a race car by all means start in second gear to protect yourself and others.

 

[Virg464]

OOPS!

View attachment 1423347

I've heard of "exploded view" in service and parts manuals, but right there at the track?! DANG!!

 

[451Mopar]

There is a bunch of confusion because most don't specify which valve body is being used, stock type forward pattern or reverse manual.
With a Stock Forward pattern valve body, placing the gear selector in second when stopped does not put the transmission into second gear, the trans still starts off in low/breakaway using the rear sprag to hold the low/reverse drum. That is the same as if you left the selector in drive.
Selecting manual low (or first) will apply the low/reverse band which will assist in holding the drum along with the sprag. Start spinning the tires in manual low and then shift into second gear.

With a reverse manual valve body, placing the gear selector into second actually puts the transmission into second gear.
Part of this came from when the early manual valve bodies did not have a low band apply feature.
The Cope racing manual reverse valve bodies have low band apply, so you could start the burnout in first if it is a low power vehicle, but still shift to second before letting off.

 

[dvw]

When doing a burnout with a stock style valve body. If it's in 2nd or D as soon as the governor see's enough rpm it'll shift. So if something does break in the drivetain the rpm imediately goes up. Then the trans shifts out of 1st. In manual 1st the stock style valve body has the low band and the low roller clutch (sprag) holding the rear drum. My race stuff does not have low band apply at all in 1st. Low roller clutch only. I've personaaly never hurt a low roller. Current race trans has 850+ passes in the high 8/low 9 ET range.
Doug

 

[66Satellite47]

This video by Cope Racing explains it very well, and with visual aids:





Here is a previous discussion of that video:

Interesting 727 info - exploding transmissions - John Cope




.

What a great video. The guy obviously knows his stuff. I guess I am fortunate that I still have my legs with so many years with a stock drum. But I do agree that would be a top improvement. A top quality sprag is sure a good idea.

 

[Gunner1]

That’s exactly what NOT to do with your 727. Never let off in first with that valve body.

Why does mine freewheel in first. I have no compression braking in first. Art Carr built mine. Did billet hub, everything. He said it was now the same as he built them for the early match race cars. Told me up to 1500 hp with big slicks. Cost me 4k with converter, installed. Was he wrong. Great video… thanks for posting it.

 

[33 IMP]

Why does mine freewheel in first. I have no compression braking in first. Art Carr built mine. Did billet hub, everything. He said it was now the same as he built them for the early match race cars. Told me up to 1500 hp with big slicks. Cost me 4k with converter, installed. Was he wrong. Great video… thanks for posting it.

Yours is the original no-low gear band apply valve body. Supposed to be microscopically faster, and have a cleaner 1-2 shift than the newer low band apply version.
Just abide by the rules above for keeping it intact, and you'll be fine, especially if it has a good drum in it, which should be the FIRST thing done in a $4k trans.
I have had two no-low gear band apply rmvb in use in my cars for twenty or thirty years. Each.

 

[451Mopar]

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.

 

[Kern Dog]

I must have either been lucky or never made enough power to be in danger.
I've peeled out in the red car numerous times. Always with a Sure Grip, well, almost always. I never sat still while I was smoking the tires, I hammered the gas and moved forward and tried to get it to spin through 1st, second and into 3rd. Always on dry pavement, no concrete or sandy surfaces.
I've read that it is brutal on transmissions to spin tires in low traction surfaces like dirt or gravel then onto pavement. The instant shock of traction supposedly leads to destruction.
I had this car off road quite a bit....

I had the one wheel peel 8 1/4" axle spinning every time I was off the road. It had a 360 and a 904 though. It has been said that the 904 didn't have the same tendencies to blow up from burnouts as the 727 does.