2007 Suburban - NO OD?

[Eckie]

I think my overdrive went out -- but I'm not 100% sure....RPM's at 65MPH are over 2000...which seems a bit high.

Also, the tell-tale sign is -- when I push the OD button (towing), nothing happens.

Could this be something else besides what I think?

108k miles on it.

[Scott K]

I dont think in 07 in disabled OD, it just locked a band to toughin it up for towing. "Tow Haul"

[littlebear]

I have a 2007 Silverado, and would assume similar drivetrain.

I believe around the same speed you indicated, it's somewhere around 2000 RPM in mine, and that's in OD. There is no button to override OD, only the gearshift can do that. The button is TOW/Haul, and will only hold the gears longer as it shifts through them.

I would guess an easy test is to shift down to D, and if the RPM's increase to the high 2000's to 3000, your OD is probably working.