Speedometer cable question

[Zoofly]

I will be replacing the bulbs in my gauges so the dash panel will have to be removed. It is a custom one-piece dash from Allison's so I have six thumb screws to remove to pull the cluster. My question is, how is the speedo cable unplugged? I've never seen it. Do I just pull it apart from the gauge? Or does it unscrew? Is it easy? Should I have Mark do it? Thanks

[TX82FIAT]

There are two types of connections for the speedo cable behind the dash. You 1978 1800 should have a plastic sleeve that slides back opening prongs/teeth that attach to the back of the speedo. It could also be a screw on type if someone changed out the speedo at some point. To re-attach simply slide the sleeve forward and it should click when fully fastened. With that said, you may want to consider unhooking the speedo cable at the trans so you have some slack in the cable to work with. as you unhook and hook to the back of the speedo. I have big hands and have always found it easier to unhook the speedo cable at the trans then work on the speedo. Hope this helps.

[NSFIAT]

In hindsight I wish I’d unhooked the cable at the trans to provide extra slack - the simple act of pulling the dash out ever so slightly was enough to break the brittle plastic of my 81’s cable attachment.

[Zoofly]

Thanks for the replies. Disconnecting the cable from the transmission may be the way to go. I'll look to see how to do that.