Speedo cable leak - ‘84 NP208

[Bob Q]

The NP208 transfer case on our ‘84 K2500 is leaking at the speedometer cable. Is this caused by bad seals in the speedometer cable adapter in the tail housing or is there supposed to be a seal or o-ring on the speedo cable itself?

Thanks.

[Accelo]

The cable doesn't have a seal in it. It is made to be hand tightened.
I suspect the seal is bad on the speedometer output. If it has a plastic gear they seal tends to wear the gear. To fix it you will need to replace the seal, and possibly the gear. I believe the aluminum speedometer adapter is pulled and the plastic gear and seal replaced. Should be a small wire seal retainer that is removed and then the seal.
There is an aftermarket seal that relocates the seal wear area to a new spot on the gear shaft. You can purchase new plastic speedometer gears on eBay for about 10 dollars. You will need to know the tooth count before ordering.

[Bob Q]

Thank you for the information. I’ll check that out.