I just got an 04 with the LLY, did they also beef up the tranny or make any mods?

There was a tranny change for the LLY. An extra solinoid, different programming and valving (I think). I'm sure someone will have all the details. I don't know if they "beefed" it up.

Here is what has changed in the Allison for the LLY.


http://media.gm.com/division/powertrain/products/transmission/2004/2004Allison.doc

So far adding the G solenoid by Allison seems to be a good thing. It drops the mainline pressure when throttle is below 8%. One thing i read in the Allison manual that i didn't like was that the G solenoid also dropped mainline pressure to the converter to betwwen 70-110 psi.Normal is 165 acording to gauge on my trans. This tech concerns medium size trucks that are serviced by Allison. Does it concern our GM's ? i don't know till i find a way to tap into the converter pressure. The Allison only has one pressure tap (for mainline). we don't know exactly what the clutches see and what the converter sees. We will know soon.


mike

Thanks GMCSID that was a good artical.