va350
Full Access Member
My speedometer on my 87 F250 is jumping and running fast. Any ideas what to look at first?
Speedometer jumping
- Thread starter va350
- Start date
Lube the cable
ghunt
Full Access Member
Does an '87 have the electronic speedometer?
In my '94 the speedo was electronic and I had issues with it jumping...and it was apparently the sensor (which was in the rear axle). Tried replacing it with a new sensor and it was even worse, so I left it alone. Sucked though because I couldn't use cruise control.
In my '94 the speedo was electronic and I had issues with it jumping...and it was apparently the sensor (which was in the rear axle). Tried replacing it with a new sensor and it was even worse, so I left it alone. Sucked though because I couldn't use cruise control.
IDIBRONCO
IDIBRONCO
From what I understand, the Borg-Warner 1345 transfer cases had a problem with speedometer gears wearing out prematurely. I talked to a transmission repair shop and the owner told me that the way to fix the issue is to remove the fill plug and install a street elbow in it's place. Then you add an extra 1/2 to a full quart extra fluid. Of course you use your fill plug to close off the top of the elbow. This could be the problem. You will have to replace the gear in the transfer case as well as the one on the end of the cable.
va350
Full Access Member
Does it connect to the rear axle or tranny? Didn't see anything on the tranny?
You have a mechanical speedometer that is connected to the transmission.
Which 87 is it the C6 or ZF???
Both are mechanical speedo capable.
va350
Full Access Member
C6, I found it. Thanks!
If it's mechanical, definitely replace drive gear and driven gear. If I recall correctly, all C6's had steel gears permanently machined onto the output shaft. If so, you're lucky, you just have to replace the driven gear on the end of the cable and it's like $10 from Ford. Just get the one with the correct number of teeth.
