speedo going nuts

[ownedueasy]

It done it a little bit about 4 months ago then stopped.. now it's going it every time I drive the truck.. sometimes it goes crazy sometimes it just doesn't work. The link is what it's doing. Anybody know what's causing this and how easy the fix is

 

[Eagle]

Is this in the '92 MJ shown in your profile? If so, you have an electronic speedometer, so it isn't the speedo cable. Your profile also says that you are converting to 4x4. Have you done the transfer case swap yet -- or have you had the speedo drive gear out of the transmission for any reason?

 

The reason for asking is that the carrier for the speedo gear has the bore for the gear slightly off-center, and it has to be mounted in a certain position depending on your gear ratio (actually, depending on the number of teeth on the speedo gear). The drive gear is nylon. If it wasn't installed correctly, it may be worn or it may have stripped the teeth.

[HOrnbrod]

^^ That is all explained with pictures HERE. Also unplug the speedo electrical connector on the transfer case and clean it up with some contact cleaner.

 

 

[ownedueasy]

No, this is in my 91 sport truck 2wd 4 banger 4 speed

[HOrnbrod]

It's still an electronic speedo and all the above is applicable, except the speedo gear will be on the transmission left side.

 

[ownedueasy]

Ok thank you very much, will have a look at it when the snow quits