Trans slip ? Allison 04.5

[carco]

My Edge/Attitude in level 1, displayed up to 2%, fluctuating from 0 to 2%, trans slip last weekend on a trip. GVW was about 21000#, gooseneck and atv,s. The only time slip was indicated was on I-75 Jellico hill in N. Tn. in overdrive @ about 65MPH. This hill I think is about a 6% grade. Last year in Colorado no slip was observed on any grade and some were steep!

Any thoughts? Is this an acceptable amount of slippage?? I think Gm has noted up to 50 RPM slippage in OD is a rule of thumb, but does this apply to the Allison?? 2 to 2.3 % would be close to 50 RPM.

[More Power]

If the ATF fluid level and color are right, just keep an eye on the slip over time. If the slip is a problem, it'll get worse - till it eventually begins setting codes.

Jim

[carco]

Oil has been changed 2X in 60000 miles and filter changed with each service. I change a little more often due to pulling 21-23000 GVW in hot weather.
Had hoped someone had seen trans slip and had an idea of/if consequences. Thanks bob...................