TR6 Speedo gear housings :TR3 and TR6

[karls59tr]

I have a TR6 trans in my TR3.Will a TR3 speedometer gear housing thread into a TR6 transmission without any issues? I'm assuming a TR6 speedo cable could then be connected to the TR3 Speedo gauge. Alternatively could I use a TR6 gear housing and mate that up to a TR3 speedo gauge?

 

[TR3driver]

The TR3 cable will fit right onto the TR6 fitting.

But I'm not sure offhand about interchanging the housings; been too long since I messed with a non-OD gearbox

PS, if it is a late TR6 gearbox, your TR3 speedo may read about 10% low. The TR6 speedo drive ratio changed around 1974 (same time as the J-type OD was introduced) from the earlier 5:2 ratio to whatever makes the cable turn 1000 times per mile.

 

[karls59tr]

Thanks Randall PS I see you have a Stag. Is it true what I hear about people finding chunks of left over sand casting in Stag engine blocks?

 

[TR3driver]

Is it true what I hear about people finding chunks of left over sand casting in Stag engine blocks?

It very definitely happens ... there was a fairly recent, high-profile restoration where they found an entire casting core still inside the engine! However, I've not had mine apart yet, so no personal experience.