torqueflight sprag fix...

[wayne petty]

after years of working on cars.. i cannot count how many torque flights i had to swap out do to the sprag tearing out of the case...

in the past...  i just bought another case... and put it together and hoped it would not happen again..

this might be usefull info for the few rodders running torque flights.. as a preemptive repair...

http://www.moparmusclemagazine.com/techarticles/drivetrain/mopp_0901_transmission_drivetrain_breakage/photo_06.html

i also don't think the sprag functionality is described fully...  my knowledge is that it overruns in forward.. cooled by the cooler return... and only works in reverse..  and is usually ripped from its mount when the gears are changed from forward to reverse with the car still rolling forward...

i was on the next torque flight somebody ask me to build for a high power motor..  going to examine the back of the case. and see if i could get the back of the case welded up on the inside to fill the area around the sprag mount area...  so it is much tougher..


this also looks like i might be able to save some of the cases after they tear out if not too much damage has been done..

[Crosley.In.AZ]

bolt in sprag race has been around for years...  

sprag holds in low gear,

usually when the race , sprag , rollers are destroyed in low gear with the shifter in "D" the rear band is not applied.

in "1 "  on the shifter, the rear band is applied to aid in holding power to the sprag

[wayne petty]

thanks tony.. that makes a lot more sense about how the sprags are ripped out..

the band just did not have enough time to apply after the gears were selected before the power was applied...


ohh.. i guess i also missed it somehow...    sure am glad that somebody had a fix ...

[SKR8PN]

bolt in sprag race has been around for years...  

sprag holds in low gear,

usually when the race , sprag , rollers are destroyed in low gear with the shifter in "D" the rear band is not applied.

in "1 "  on the shifter, the rear band is applied to aid in holding power to the sprag

Except with most reverse pattern valve bodies. A&A  and a few others now make a rear band apply valve body to help. Another thing to be very aware of when using a valve body that does NOT have rear band apply,is that when the sprag "rolls over" or rips out of the case, the front drum will overspeed to 2.5 times engine speed,which results in some very nasty carnage if your running a STOCK front drum.


Check out this thread from another board.
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=Racer&Number=4782213&page=0&fpart=all