Hey guys need a little help. My trucks an 01 1500 quad 360 4x4. The speedometer lags when you accelerate hard. Also noticed when stopped my oss reads 20 but seems like it doesn't lag but climbs in 20s (500-520-540-560-etc). Could it be oss or rear axle speed sensor or gauge cluster? No dtcs or abs light. Just an annoyance I'd like to fix while redoing the truck

 

You can test the cluster, hold in the trip reset button, while turning the ignition on. (don't start the engine.) The cluster will run thru its tests. (including sweeping all the gauge needles.) If it passes that, I would look real hard at the rear wheel speed sensor, as that is where the PCM gets it clue from for the speedo.

 

Will it tell you pass or fail or just have to pay attention?
Thanks for the help!

Ok, update. Did the cluster check and everything works and moves fluidly. No lag.
Thanks again. Gonna try a new speed sensor. Thanks!