Well if anyone ever wondered if a low band apply valve body works, I am here to tell you... it does... and it doesn't.

I believe I have abused my 727 with about as much as one could do.

3700lb car
2.76 gear (read VERY HIGH load in the trans)
Trans Brake launches
8psi of boost at 4400rpm

Car ran 10.67@127.71 if that gives you an idea of power.

Trans started "shuttering" on launch, and later developed a slip during the 1~2 shift. Once in 2nd gear it was fine, but had a little "flare" on the shift. Then started making some driveshaft speed grinding noises in 2nd/3rd during coast down.

Took the trans apart last night. First of all one of the exhaust hangers were broke, so it was hitting the shock (part of my clunk). Second of all, the trans mount was broke (even more part of my clunk).

Decided to take the trans apart anyway, just to make sure everything looked good.

Lots of metal in the pan, got down to the low roller (sprag) and it was destroyed. Fortunatly it didn't hurt the case.

Now I have a tranzact valve body (trans brake) with low band apply.

I obviously made several mid-high 10 second passes on a broken sprag, so the the LBA definately kept the trans from coming apart.

However, the LBA did NOT keep the trans from destroying the low roller.

Take what you will from my experiance, but my feeling is the following.

1) The LBA function will keep you safe. I think this experiance proves that.

2) The LBA will NOT prevent sprag failure. If you want your trans to live a long happy life, you still need a good sprag regardless of if your valve body has LBA or not.

Anyway... just wanted to share. Getting parts tonight, back together tomorrow, off to Stanton this weeekend to make some more runs.

Upgraded the car to 3.23 gear (from a 2.76), and I also bought 275/60's for it (replacing the warn our 255/60's).

We'll see if we can get this ol' heap below the 10.50 mark!!!!

Parts...

hogwash , that trans would have lived another 1000 passes like that ....

...

Are the splines stripped off where the front planet mounts also ?

LOL...maybe it could have... but 2nd gear wasn't happy. I did have the finest in used bands in it... can't possibly see why it wouldn't live...


Planetary's were perfect. Actually it didn't hurt much. Needs a new sprag, new 2nd gear band, and one plastic thrust washer. That's it.

Are you putting in a Coan or A+A sprag ? Anything else is a waste of time and money.

Was your front band Kevlar ?

Coan. And a new Kevlar front band this time.

If you were whaling on it from a standstill in Drive, you could still do that damage. LBA only works in manual Low.

Kevin

I Love That Car !! What engine do you run in it?

I believe my 60' was going because the sprag was going bad but I mistook it for tire slip and soon after I lost 1st pulling into the pits on my way to tech in at the track.I have the coin super sprag now.

The kevlar band works for a while but it doesn't hold up well to stopping a spinning drum , after a while it will begin to slip. That's why it's ok on the rear drum, the rear drum only tries to turn when going in reverse and the band grabs ahold it it before it can get any speed going.

Oh course now someone will come on with a HOGWASH , I have 1,000,000 passes and 500,000 street miles on a Kevlar band , it's been in there since the dawn of time and I've never had an issue .

You'll see more instances of glazing with the Kevlar band than the red.

correct the material is to hard and becomes glazed very fast

I put 500 passes on an iSonnex Kevlar band in the mid eighties. The oem front drum, wore to the exact band pattern. You could still read the logo and part number on the band. So yeah, there was some frictional coefficient compatibility issues happening. I kept the band for a core, I should dig it out, and post a pic of that thing.

Got the Trans back together tonight. Unfortunately I had to put a kevlar band in it because it was all I could get on short notice.

Got the super sprag in it...and just in case anyone is wondering, it is most definitely not designed for a push button Trans case. Took some engineering and machine work to make it fit.

Off to Stanton this weekend as long as the new tires fit and the Trans shifts tomorrow when I put fluid in it.

kevlar band is fine there is one in my trans it has 1million miles and 4000 9 second runs on it LOL red ft band would go away after some 300hp no2 shots ?? just my experiance not to start a wizzing contest, can ya still get the kevlar band? mabe crt will chime in ??

you run 10.70 in a 3700lb car with a 2.76 gear? I HAVE GOT TO HEAR ABOUT THE MOTOR!