I used a crown unit and had the opposite problem... I now have oil coming out of the back of the speedo from the t-case?!?!?!?! t-case vent is fine and breathing, so it's not pushing it up the cable. I've just never had it happen before.
To the OP, I've lubed OLD speedo cables in the past to quiet them down. that was 8+ years and 50K ago. no problems. I wonder if your speedo is starting to sieze up causing straign on the cable?
It's the whole cable and housing, looks identical to the old one. When I installed the new cable, I gave the little brass nubbin on the back of the speedo a spin and it was smooth as butter. When I pulled the old cable out of the t-case, there was definitely grease on the fitting where it went into the case, but eh speedo end was dry and clean. Cable was twisted up in the housing so I couldn't pull it out for inspection.
Not sure if these are related to the breakage, but:
The speedo needle does "bounce" when I'm in the 20-30 MPH range, then stabilizes at higher speeds.
And, I clocked it with my GPS, and the speedo is almost dead on up to about 35 MPH, but by the time I accelerate to 50 MPH on the GPS, the speedo needle is maybe 5MPH fast, displaying 55 MPH.
Will pick up some if that powdered graphite stuff when I get my new cable, thanks much!
Jeep: Every adventure is a repair, every repair is an adventure!
My speedo does the bounce thing up in the higher speeds but not low. A new one is in the plans. Yes graphite or any "dry" lubricant is what I've always heard to use. I figured they'd be lubed from the factory.