In my case, the speedo is working fine (actually, I just changed the gears to 38 when I finished the SYE last weekend), and the TB I cleaned in January when I tried to do the 4.0L TB install (at that time, I even thought the reason the 4.0L was not adjusting the idle correctly was because of the sensors, so I bought new ones; although it still did not idle correctly, I left the new ones in on the 2.5L throttle body - I think the reason for the bad idling is that there is some corrosion on the side of the TB which lets air through).
Felipe