FORD C4 issues

[Sharky]

I have a performance automatic C4 in my coupe & it died when accelerating onto the highway, no forward or reverse gears. I 1st drained it & pulled the pan , no parts or debris in the pan & the fluid looks good. pulled the valve body & again all looks ok. after removing the trans I pulled the torque converter & tried to rotate the shafts.
cant turn the stator (?) shaft and the input shaft will rotate with very little effort in the clock wise rotation but feels like it is skipping teeth in the counter clockwise direction ?
I dont know squat about auto transmissions so I would like your thoughts on what is wrong or broken in the trans.
it will be going in for repair as soon as I can get it to a shop. thanks.

my coupe.....

 

[19Walt93]

Nice looking car. The stator doesn't turn, it's part of the front pump body. Have you pulled the input shaft out and looked at it? I rebuilt an FMX once and the input shaft snapped in two pieces shifting 1-2 at WOT on the road test. I've seen front pump gears split but that would have made a noise and there would likely be metal in the pan. Did you do a pressure test before removing the trans?

 

[Sharky]

I did not do a pressure test , I did remove the input shaft & it showed no wear. put it back in &
it still rotates the same way. sure feels like some teeth are missing when turning it counter clockwise ????? thanks for your input

 

[19Walt93]

May be time to remove the pump and take it apart. If you get away with just a new pump make sure to check the end play. On a C4 it should be between .008 and .042", I shoot for somewhere in the middle of the range..

 

[Sharky]

update : dropped the transmission off last Thursday & was told today the the splines were wiped out in the drive drum. input shaft is good, just the drive drum is wiped out. the man said he has seen this before, the factory drum does not hold up to 500 hp.
this is what is getting installed : https://www.ckperformance.com/View/C4-BILLET-FORWARD-CLUTCH-DRUM

 

[Sharky]

I got the transmission back today. pics of the forward drum failure:

 

[19Walt93]

I hope it got a complete overhaul, otherwise metal particles will tear it up quickly.

 

[Sharky]

I hope it got a complete overhaul, otherwise metal particles will tear it up quickly.

it was a complete rebuild although the clutches & other parts looked new.

 

[19Walt93]

it was a complete rebuild although the clutches & other parts looked new.

Good, I wasn't concerned about wear because it was a sudden failure.