HDJ80 diesel tach interchangeability? (1 Viewer)

[HRTROB]

I have a 1996 HDJ80-GNMEX (12 valve 1HDT). The tach has been acting up for some time now. It would drop to zero or a couple of hundred rpm. If I tap the cluster with my finger, it would return to normal but would drop again after some time, ruling out a problem with the tach wiring from the pump. My question is, are the tachs interchangeable between ATM and MTM? There’s someone selling a tach that looks like mine (T-BELT and overboost lights) but I believe it might be from an automatic because it has “ECT” written on it. The part numbers of the ATM and MTM tachs are different according to my research. Does anybody know if they are interchangeable?

my tach and cluster:

The tach in question. Has “ECT” written on it:

 

[TurboDennis]

Yes, tachs are different, and non-interchangeable. Tachs that came from auto tranny trucks, or trucks with EGR valve on the engine (1HD-FT only, as i dont think 1HD-T's ever came with EGR) will NOT work on your truck.