Recently I took my truck up a steep logging road and got my tranny temp up a bit. My abs light came on and then my speedo wouldn't register more than 30mph. When I take off, the speedo will slowly climb but never gets above 30 no matter how fast I go.

What should I be looking at and where is it located?

 

im not positive on these trucks, but older vehicles used a plastic speedo gear, they would wear with heat especially. for all i know though your 24v has a speed sensor on the rear axel.

 

it sounds like your ABS/speed sensor. when mine went out it kinda did the same thing, it wouldn't register untill i hit 15mph, then it was fine. the part is like $40 something at checker (aka: Schuck's Auto Supply, Kragen Auto Parts, and Murray's Discount Auto Parts stores) and only takes about 10 minutes to put in. it is located right on top of your rear diff.

 

Yea, You had so much fun offroad that the speed sensor wiring got damaged. Should find a problem on or very near rear axle.

 

i agree with Cody D. The ABS sensor in the rear diff is probably the problem. Or the wiring to it one.