Checking Oil Level (3000/4000) :
When i change transmission oil, before i drain it, i mark my dipstick to where the current cold oil level is with an exacto knife or something. I drain tranny oil cold because it is synthetic and hence flows nicely. Generally this level is far higher than what the dipstick shows as hot/cold mark. You do this once only. After draining oil, i just fill oil upto this newly marked level.
Next time , i am driving and the oil is hot enough (140F or more) and i am on a level surface, i use the allison pad and press up and dn arrow together. It counts down 7..6...1..0 and tells me OL--OK (ie oil level is good)
So i don't have to worry about warming the oil after a fill to check with the tranny pad since the oil is cold at the time and tranny pad would give you the reading.
It has worked for me for many years and i have used this method in 3000 and 4000 series allison transmissions.
