changed out the whole rear end and now the speedomoter jumps when i get to 50mph.It jumps to 100 then back down etc.
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1990 Ford F-150 Question: why does my speedometer jump when i do 50mph after replacing the whole rearend
Answer #1pushrod December 02, 2012, 06:47Master
ALL you did was replace the rear diff? The only connection to it is the drive shaft unless you hit something on the trans. i dont see how the speedo. circuit was damaged! Was there ANY other parts swapped? Was the diff. exactly the same?
Same drive shaft, front yoke same length?