ScottG wrote:
SoCalDesertRider wrote:
A 4500/5500 cab/chassis truck used for commercial purposes is often a very heavily used and abused truck. It's service intervals would fall under the 'severe' category. If the owner's manual says change it at 7500 miles, that's what I would do.
The manual says 60,000/120,000 miles depending on duty cycles.
That sounds awefully long, for a severe service interval. Is that from the owner's manual for a pickup, or a cab/chassis truck? Is that for auto tranny or manual tranny? 60K/120K sounds like service intervals for a manual tranny to me.
I agree that 7500 miles seems awfully short to be changing tranny fluid.
I would expect the manual to say something like 15,000 severe, 25,000 medium and 50,000 light duty service intervals for auto tranny fluid in a medium duty class 4/5 commercial truck.
