8V92 Transmission Modulator Linkage Disconnected!!

[carson357]

the linkage to the transmission was/is dissconnected, i called the guy i bought it from and asked him about it, and he said that since it was repowered from 8V71 to an 8V92 that the passing gear was not needed since the 8V92 was so much more powerful. i Listened to him, and was always taught to respect elders so i didn't question it further, i thanked him for the info and hung up. i am a mechanic by trade and know that on cars the cable does more than act as a simple kickdown/passing gear. seems from my research that for this Allison unit it actually acts as a modulator. now the trans does seem to shift odd, but this being my first bus, i am not sure what usual is, i looked on the linkage and do not see where to connect it.
any input on this would be greatly appreciated. also pictures would be a big help as i will be fabricating something to connect the linkage soon.
thanks for any input

[JackConrad]

I would reconnect and adjust the modulator. Do you have a mechanical throttle linkage aor an air throttle? Takes a different modulator for an air throttle.  Or, is the 8V92 a DDEC?  Jack

[TomC]

The modulator needs to be connected.  Yes it does control the "passing gear".  But more importantly, it allows the transmission to shift at a lower rpm on partial throttle.  On my truck with the HT740 mechanical, in 3rd gear with light throttle, I've seen as low as 900 rpm with the torque converter locked!  And on my V730, on partial throttle, I can see 1200rpm in second.  You'll actually get better fuel mileage with the transmission lowering the rpm on the engine.  The 8V-92TA can run down to 1200rpm with partial throttle without harm.  Good Luck, TomC

[David Anderson]

Not trying to hijack the thread, but TomC.  does that 1200rpm lower limit apply to the 6v92, also?

David

[TomC]

Yes.