shift issue

Hello AllisonMan,

I'm new to this site and tried to see if this had been asked before but could not find anything. I tried to send you an e-mail but do not know if it got thru (not real computer literate).

I have a new (2004) chevy 2500HD (8.1 w/Allison 1000) that I bought to pull a 32ft. gooseneck. I'm loaded most of the time near the max Chevy allows (20,000lbs). On the maiden voyage I noticed when pulling "grapevine" in CA, that during the down-shifts RPMs would initially increase by about 1000 (from 2000 to 3000) but would then drop 500 of that (back to 2500) after a few seconds. Transmission temp never went above 180 and it did not appear to slip.

I stopped at an Allison Dealer in Sparks, NV - they said that this was not normal but said they could not do the warranty work on a pickup. I had them change it over to TranSynd and put on a new spin on filter. Did not make any diff. My Chevy dealer said they didn't know what it was. Any thought? I am going to have Allison put the deep pan on. Is it possible to change the shift points? I don't care so much about smooth as I do about the transmission lasting. Thanks in advance. Dale