the 34 element hd sprag died (rolled) in my 4l80e
probably during a ~7000rpm 1-2 shift

engine is a 4.8/gt45 turbo e85/19psi

it is in a ~4500lb jeep wrangler

trans is a 1997 year model 4l80e with a transgo hd2 kit and a circle d billet ~3400 stall

anybody have a good source for the upgrade? (36 element with "super" drum)

i was gonna order one from ck performance but they are closed all month for vacation

need one asap

 

http://ftiperformance.com/product/th...-intermediate/

In stock.

 

Be aware that a TH400 piece with a 400 or early style 4L80 pressure plate will not fit in the late 80E case without fitting.

Also, the clutch pack clearances will often need to be setup and a lathe may be necessary to cut alternative parts.

 

by early vs late 4l80e case you talking the front vs front/rear cooler lines or the pre ls vs post ls (top bellhousing bolt?

part of me wants to just put it back together with a 34 element and lower my shift points to under 6500 but if it is still gonna break at that point its gonna make steam come out of my ears

from reading it seems like it is either 1-2 shift rpm or vehicle weight or both taking it out

people talk about the 34 element one surviving with 750-1000 hp but that appears to be in 2500-3000lb cars

the fti one listed above is an aluminum drum which i read was not super recommended for a street/driver vehicle plus it says it is a th400 piece

 

Sprag failure can be caused by shift calibration, rpm, gearing, etc.

The 34 element can live at over 1200 HP even in heavier combos but some combos are sprag killers.

Aluminum drum takes the load off the sprag because it's lighter. 7000+ rpm and aluminum drum is not a bad idea in any case. On a street combo, the trick is knowing which aluminum drum to use and how to set it up.

 

for what it's worth, l believe the sprag rolles, just one side, because the drum is allowed to be off center. l have no connection to ATl but they copied my direct drum support idea and you can get the parts from them. Don't ask l have none for sale. Good luck

 

For some reason I believe the 34 element sprag is worse than the standard old style T400 sprag. Maybe because I've had good luck with the stock sprag in several full manual T400's now, street driven and raced, and reverse manual with no engine braking. While others were rolling 34 element sprags off the line. Fluke maybe?

Everytime this issue is mentioned I feel like just buying a Powerglide. But I like the driveability of my T400 on the street with tall rear gears.