Never broken one before.....full weight e body with drag radials, 402 small block, 727, turbo action fmvb, 3.91

Pulled out on street, poked it...car went sideways, I lifted, and poked it again.

ZIIIIIZZZZZZZZZZ

car moves under own power but any throttle produces more ZIIIIIIZZZZZZZZ.

not what I needed on a car I planned to drive to Carlisle in two weeks



Pulled trans, everything looks fine........then I had an epiphany.....loose converter, Mancini low gear pack, sticky tires, old OEM gear set..

I'll bet I stripped the ring n pinion. That would explain motion in all gears, but ziiiiiiiiizzzzz upon throttle. I heard it under the shifter, but that could be gear noise resonating up the driveshaft.

I had a meeting tonight and couldn't work on it...tomorrow night I'll pull the diff, and ill bet it is hurt.


Pulled axles and diff...

1/4 inch of splines were ripped off the right side axle

Put it in manual low. If it goes then ya busted sprag.

They all go in manual low ?

time for a powerglide

That would be a gross way to live. No thanks.



Really just hoping anyone could tell me if this sounds like a sprag or not.

You said fmvb...., full manual valve body ? .... no go in first gear but it will move in second ? Probably a busted sprag BUT NOT the end of the world .... replace the sprag -

My advice is when in doubt, check it out Don't find out later after it explodes that you hurt it enough to hurt you

I just fixed one that had a partially failed roller clutch after breaking a rear. He was also starting his burnouts in low. Car drove OK with no noise. Had a TCI transbrake valvebody (LBA I assume). Guy brought it to me after I suggested it should be checked, even though the car drove fine. Half of the springs were crushed and the fingers were folded over. Would not have survived another hard hit.

Stock drum 727? I would treat it like a grenade with the pin out until it was looked at. Gasket kit and time are cheap.

Two guys above have valid observations...,,,

Drop the pan ... there should be spring trash in there too

just dropped the pan. zero trash.

the car will move in all gears........until you touch the throttle. then ZZZIIIIIIIIIIZZZZ from under the tunnel.

I did find two bolts convertor that were backing off. but that cant be it


and yes, "fmvb" = turbo-action forward manual valve body (forward to allow my slap-stik to work, no LBA) been in for about 10 years and 8k miles.

slip yoke splines are perfect. as are trans output splines.

car was perfect for 87 miles today, then I nailed it, spun, lifted, and tipped back in......why I was thinking sprag.

All in low gear and nitto 555r tires.

Missed the part about RMVB. Woopise.

It's not rmvb......it is fmvb.

My bet is hard part failure. The sprag won't disable 2nd, 3rd, or rev. Stripped input shaft hub or broken planetary.
Doug

I agree... Or cracked a drum...

methinks you need to get that thing out and on the bench now. you still have lots of time before carlisle to go through it.
don't put it off and give it a chance to BITE you ! it will not treat you with a "love tap" if it gets it's chance.

How many rpms were you running at the time you hit it... MOST times
when a sprag gives out is when you get off the pedal then hit it again..
I blew a rear end in the race car but it didnt hurt the sprag.. I pulled the
trans for a check but it was fine.. the getting back on it after letting off
is what can hurt it... its that slap of the rollers that can break the roller
case.. in a manual VB its hard to tell if you cracked it.. pull it now while
you have the time... good luck

Does that include Reverse or just the forward gears? In any case, it needs to come out, no easy external fix.

All gears including reverse

Short answer: Remove transmission and have it checked out.