2010 V8 4.6 5 speed won't go into gear while running

Ok so as I was down shifting into 3rd to make a turn I heard a decently loud pow/pop and lost the ability to shift into any gear. Few days later I dropped the transmission to find out the clutch shattered into many many pieces, very old clutch as it was anyways.
So I put a brand new clutch kit, slave cylinder in and put it all back together. Cranked up the car with no issue until I tried to go into any gear, it just won't it's like they are all locked out. If the car is off it'll go into all the garages with ease. After reading online it seems my problem could just be a faulty slave cylinder. So a lot of head scratching, hair pulling and vacuum bleeding the hydraulic clutch with still no progress I decided to drop the transmission again and put in a brand new better made slave cylinder, bench bled and all that.
I decided to test it after getting the transmission and shifter back into place before attaching the drive shaft and while running went into each gear like butter, so finished putting the car back together and now it won't go into any gear again, if I put it into gear 1st and try to crank the car it wants to jump forward but won't turn over.

Is there something I may have missed? Is it possible to put a clutch in backwards and it cause the symptoms I'm having? I've been fighting with it for a couple months now and desperately need to get it back on the road so any advice or thoughts will be greatly appreciated.

Noobz347 said:

Refresh my memory:

Is there a transmission inspection plate on the bottom of your rig?


If so, get a second pair of eyes (or feet) to operate the clutch while the other watches for the Throw Out Bearing (TOB) to fully engage with the clutch and see if you get your peepers in there to determine if the clutch fully disengages from the flywheel.


Do you happen to have a set of installation instructions for the parts you installed? (bleeding instructions for the bearing, specifically)

Part numbers perhaps?

Did you use a clutch alignment tool for installation?

Is the transmission [fully] flat against the engine block?

Click to expand...

Yes there's a hole that you can look up into and see where the TOB meets the clutch and can see it travel while the pedal is being pressed. Buddy that was helping me even had a little camera he stuck up in there while I was working the clutch and from what he could tell it was all moving.

The only instructions the clutch came with was a bullet point paper saying drop trans, remove old clutch and pilot bearing, install new and put car back together..... So no not really but I've done clutches in the past on other vehicles and for the most part it's pretty straightforward. I also looked up a lot of different videos and other things to help make sure I put everything back exactly the same way it came off (did them back to back) and also learned that it needs bench bled which I did not do on the 1st one that came with the kit but I did on the new one I installed 2 days ago.

Yes I used the alignment tool, even stuck it back in there when I dropped the transmission 2 days ago just to make sure and to line back up correctly when I put the trans back.

Yes the trans sits fully flat against the engine, it has a cover plate that goes on it in between but other then that it's flat.