Has anyone experienced anything like this before this before?
I just changed out the rear in my truck the new one has a 3.73 gear the old one had a 4.10 in it. While I figured I would probably have to change the transfer case speedometer gear ratio to compensate for the rear gear change but what I am seeing is the speedo needle bouncing below 30 mph. I drove the truck exactly 20 miles (according to the mile markers on I90) and was surprised to see that my odometer was only .5 off over that distance. So if I figured it right that would be around .025% or 1.25 mph off at 50 mph
Not enough to worry about. So I have no plans to change the speedo gearing but I still need to figure why the speedo needle is bouncing under 30 mph.
Now if I can just remember not to shift in to 4wd before I change the front gear.
Bill
Try lubricating the cable & casing from the top. That ought to correct the bouncing,
as long as there is nothing wrong like a frayed inner cable, a kink, etc. . .
yes, lube the cable, but also consider taking the speedo head out of the dash, opening it up and cleaning and lightly lubing everything.
Could also be an artifact of your odometer trying to jam up, but it doesn't sound like it,as it is reading pretty accurate.
The odo in aggie worked fine, shortly after I put a new speedo set in the trans, but jammed up when it tried to turn over the 10,000 mile dial. Even if it currently works fine, If you have never lubed the odo, it would be a good idea to take it out of the speedo head, soak it in a cup of water to get all the gunk inside loosened up, blow it all dry with compressed air, then squirt a bunch of powdered graphite inside the barrel, and blow all that out.
My original odo shattered, I found a replacement, which was all jammy too, and did this to it, spins around beautiful now. I set it back to 0, as I had just rebuilt my engine, and the original odo indications didn't mean anything, then had been missing for about a year after it broke.
and yeah, i think some really exciting things would happen if you threw it into 4wd. haha
Granted, it was not an issue of mismatched gear sets, but my roommate's family recently had a bit of drama with 4low... his dad was driving fast down the highway, and for some reason, his ma got "scared" and yanked it into 4Low. why the HELL she did that, I don't know, but it almost broke the truck, and jammed something up so it wouldn't come out. They called a service Rep from Ford, and they told them to drive REALLY FAST, BACKWARD, in a CIRCLE, to "unwind" something, and pop it loose. Apparently it worked.
'63 with 390 & lots of juice. But never enough. Always want more.
