[TR] GT6 Question

[Edward Hamer]

It looks like your trans was driven very hard and perhaps low on oil.  It looks like the edges of the splines on the main shaft have been very hot (blue discolouration on the spline ends).

The wear on the lay shaft indicates hard use as well.

When the trans is in 4th gear no power is transmitted trough the gears, the input shaft and the main shaft are coupled to direct power from the clutch to the rear driveshaft flange.  As such all the gears are spinning under no load so there is very little friction or wear to the components.

Running in a lower gear for long periods of time, such as third, places a lot of strain and therefore heat into the gear train.  "Banging through the gears" is stressful also.

The problem with GT6 transmissions is that they are upgraded "small engine"  ie Herald/Spitfire transmissions.  Unfortunatly this means that they do not have a lot of reserve strenth and wear quickly when abused or raced.

At a minimum I would say that you need a replacement main shaft  lay shaft, all bearings, synchronizers and careful inspection if all moving parts.  You should check to see if the bearing holes in the front and rear of the case are still snug on the bearings as well.  I have seen cases where the front bearing just slides through the opening.

Fortunatly some of the components are shared with Spitfire trans.  I believe that the main shaft is and the synchronizer couplings are shared.   GT6 gears are unique to the trans and are much harder to find in good condition.

By the way there are no shared parts between the TR trans and the GT6.

If your intention is to compete with the car or love to drive hard you might want to think about upgrading to a more modern trans.  I believe that Moss Motors sells kits to convert to a Ford trans.

Edward Hamer
Petaluma CA



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