3 3/8" (85mm) tach in 4" housing

[260Alpine]

This is how I adapted a 3 3/8" (85mm) tach to fit a 4" housing. If you use a black rim tach it would be less noticeable. I think it looks good though. Might do a cheap GPS speedometer the same way.

 

[Tom H]

Jim, just to be sure I understand, I assume you mechanically anchored the smaller case inside the larger one and used the foam tape to fill the gap between the two circumferences. Or is the foam tape THE anchor? Looks quite nice. I do not see the foam in the photo, so again, I assume there is almost zero gap between the two chrome rings, but enough that you want to seal that gap, right?

Tom

 

[260Alpine]

Tom, the foam strip is wrapped right under the chrome rim of the tach. Tight fit. The chrome rim sits a little bit on the larger chrome rim. I cut the mounting studs off the back of the tach to push down enough to fit flush.

 

[260Alpine]

Got the matching GPS speedo mounted. Had to drill a hole for the coax cable in the back. Also, using the existing bulb feature is red LED. I'll carefully use a hole saw to use the existing bulb in the 4" can.

 

[Mikeflbmer]

I am in process of doing similar as my t5 will not hook up to speedo cable