TR2/3/3A Speedometer cable fittings?

[karls59tr]

Anyone know if a 4A speedometer cable could be used on a TR6 gearbox? Also...would a 4A cable mate up to the back of a TR3 speedo gauge. I guess I'm asking if the knurled connectors at the gearbox have the same thread. The speedometer connection on my TR6 box (which is in a TR3)has the threads stripped out and I wonder if I can use a 4A speedo cable instead?
Is it difficult to remove the speedometer carrier once the hold down bolt is removed?

 

[charleyf]

I do know that the TR3, 4 & 6 trannies are interchangeable in the cars. As far as the cable goes there is no reason except for length that it should not work. I am thinking that there may be a length issue with a TR6 tranny in a TR6. But I do not believe that is what you are trying to do --right? You are looking at a TR6 tranny in a TR3. So it should work.
Charley

 

[TR3driver]

Getting the carrier out without damage can be kind of a pain. But since you apparently have to replace it anyway, that shouldn't be an issue.

The threads will mate up, but the 4A cable will be too short unless you are also using the right angle drive from the TR6. Also, a late TR6 box will have the wrong drive ratio. I forget the change point offhand, 73 or 74 I think (same time they switched to using a J-type OD but the ratio problem applies even without the OD).

 

[charleyf]

Getting the carrier out without damage can be kind of a pain. But since you apparently have to replace it anyway, that shouldn't be an issue.

The threads will mate up, but the 4A cable will be too short unless you are also using the right angle drive from the TR6. Also, a late TR6 box will have the wrong drive ratio. I forget the change point offhand, 73 or 74 I think (same time they switched to using a J-type OD but the ratio problem applies even without the OD).

Randall,
Does the ratio problem exist with the TR6 A type OD tranny on a TR3?
Charley

 

[TR3driver]

Does the ratio problem exist with the TR6 A type OD tranny on a TR3?

No. Just the late TR6, that would have taken a J-type. (With or without the actual OD.)

Lots of TR6 owners find out the hard way, when swapping non-OD transmissions around.