Broken C4?

[flexmerc]

here we go....
just recently completed an engine swap, and was dialing in the Holley Sniper EFI. I have regear (4.56), and a rebuilt D20 (hermtheoverdriveguy), Gear star C4, that I've been running now for over a year, and the engine was the last mechanical piece I wanted to do. I have always kept the Bronco running, throughout all these changes.

Well during my third test drive post engine swap, the bronco just didn't have the get up that it had before...it felt sluggish and I was chasing AFRs/Timing; and during an hard acceleration a very loud and aggressive clunk shook the truck and now it will not drive, I had to call the wife to tow me back to the house in my truck (yes she took a picture of me on the side of the road).

Shifter linkage is solid, and the tranny is shifting through the gears, just not engaging. I also double check the t-case, no issues there.

Any thoughts?

 

[Broncobowsher]

Does it buzz when shifting into park with the engine running?

 

[flexmerc]

No buzzing, shifts like normal and I'm unable to push the vehicle while in drive...but it will not move with throttle input.
While in neutral the vehicle will roll forward and back.

 

[Viperwolf1]

Did the tcase pop out of gear?

 

[flexmerc]

nope, slipped it out into Low and High, and did the same for the front...it has a twin stick.

No dice

 

[Big Ben]

Did the torque converter disconnect from the flexplate?

 

[73azbronco]

vacuum problem??

 

[Broncobowsher]

No buzzing, shifts like normal and I'm unable to push the vehicle while in drive...but it will not move with throttle input.
While in neutral the vehicle will roll forward and back.

So the transmission is 'locked' while the engine is running, You can load the convertor but feels like a brake is solid apply. But free to roll with the engine off.

Ignoring park position, does it do the same for all gear positions RND21? Only need to check running, off there is no hydraulic pressure and will all be the same.
It sounds like a clutch is stuck on. Either welded (transmission rebuild) or a valve body issue (probably a bit of garbage stuck a valve). There are a series of pressure tests to figure what is really happening.

 

[flexmerc]

Did the torque converter disconnect from the flexplate?

Negative, you can see the flex plate and toque converter in one of the photos