Allison Transmission Question

[hunter97321]

New to buses and diesels so please be patient . I asked this at the end of a different subject and hoped that I would get better results asking the question separately. This part https://www.dropbox.com/s/gvbq0dbjnx8d856/Transmission.jpg?dl=0 is broken off  of the Allison HT754CRD transmission in my bus. It heads up towards the top of the engine (8v71t) and I have no idea what it does other than the hole that it previously filled will pump out the transmission fluid very quickly if the engine is started. The shifter is a Stone Bennett is it part of the shifter ?

I can't tell if it is a cable, air, or fluid line. 

Is it necessary? Could I just plug the hole to get by until I can fix it right?

Any transmission gurus?
Thanks!

[wildbob24]

Hunter,

That is your modulator. It is cable operated. The other end of that red cable should be attached to the throttle linkage, probably up at the governor.

It is necessary for the proper operation of your transmission.

Bob

[luvrbus]

You have lost the c-clamp and 5/16 bolt that holds it in place check around there is a pin inside the transmission on the valve body you probably lost it also.I can post you a photo on F/B if Donald or someone else will lift it and show you the setup.If you put the transmission in gear the oil will stop fwiw