Running rough and wouldn't shift

[TorchRedTulsan]

So, I just had this happen while I was on my lunch break. Wanted to post it up and see if I could learn a little bit

Bronco has been running great. Out enjoying the beautiful weather at lunch when I stopped by a buddies house down the street. I go to leave, and the engine is running really roughly. I popped the hood, but don't see anything. Decide to drive the block and a half back to the house and notice that it's not shifting out of gear. Get on it a little bit and the RPMS run up w/o shifting. Get it home and do some looking around and notice a hose had come loose. Reattached the hose and it ran smooth and shifted again. I've attached a picture with an arrow pointing to the hose that had disconnected

Can you guys educate me on:

• What is the component the hose came out of?
• Why did it cause the engine to run rough?
• Why did it prevent it from shifting?

 

[68Rcodeman]

The hose is to the trans Modulator valve. That controls shift. You probably notice hose is swelled up? That would be from trans fluid leaking from a bad diaphram in the modulator valve. When it fell off it caused a vacume leak which cause the rough idle. Very comon. Replace the hose and modulator valve. Be careful when changing the modulator not to loose the pin on the inside. You will transfer it to the new modulator valve.
David

 

[Justafordguy]

X2, exactly what he said.

When changing the modulator some fluid will come out of the trans so be ready to put the new one back in fast. Also park with the front down hill and not as much will come out. Check your trans fluid after and add if needed.

 

[TorchRedTulsan]

Thanks! Is the modulator valve Bronco specific or can I pick one up at O'Reilly? How simple is it to remove/uninstall? Supposed to be taking the girl on a date tonight and she specifically wants to go out in the Bronco

 

[Yeller]

yes normal off the shelf item. if you need help hit me up ASAP I'll swing by after work and help you get it on an adjusted