TR2/3/3A Has anyone installed a TR6 OD transmission in their TR3?

[JFeher]

I have a TR6 OD Transmission and almost everything looks the same. The main input shaft seems to be about 1/2 inch shorter on the TR6 tranny.
Any tips on installing this?

John

 

[Don_R]

i believe the bellhousing is thicker so you need longer studs. not sure of other issues

 

[TR3driver]

You'll also need to slot the holes where the rear mount attaches to the cross member. The 4-synchro boxes are around 3/8" longer through the mounting points.

Depending on the vintage of TR6, you may need longer mounting bolts and some adjustments to the clutch slave mounting. I have a later TR6 box and had to shorten the clutch pushrod to make it fit with the slave in the original position.

The shorter input shaft does not seem to be a problem. Still, it wouldn't hurt to replace the pilot bearing while you're in there. Make sure the locating dowels are in place as well.

Don't forget to wire and test the switches before buttoning it up. In retrospect, I wish I had just replaced the one that acted a bit funny instead of just taking out the shim.

 

[Lukens]

I asked the same question at a club breakfast this morning.
After removing the old tranny, replaced the top two bellhousing bolts with studs (bolts with the heads cut off). This way you can "hang" the new tranny on these until the remaining bolts are in place. I thought this was a clever tip.

 

[Simmo]

I used a 1976 Triumph 2500TC Gerarbox and J type OD. Apart from the advice above I sent the flywheel to the clutch suppliers and they surface ground and re tapped it fot a new Diaphram clutch.
The TR3A now thinks it's twenty years younger.

 

[Simmo]

I ment also to say that modified rear mount brackets are required. It is somewhat of a pain to manufacturte and in desperation I purchased a Moss bracket. It works like a charm

 

[JFeher]

Hi Don. Thanks.

Call me. I've got a line on a local Sunbeam Alpine.

 

[JFeher]

Randall,
I haven't heard about slave issues. Good to know. The OD plate number (1975) says its from a TR6 from April of 71. I think its one of the last series of A types.

Moss shows the same part number for the pilot bushing in the TR3 and TR6 so I think I should be good there. It does mention a flywheel bushing on the TR6 but not the TR3, but I'm not sure that would make a difference since I'm using the TR3 flywheel.

Thanks,
John

 

[Marvin Gruber]

The late TR6 o/d has an entirely different rear trans mount. You can make it work but there are some mods to make, otherwise like the guys before me have mentioned.

Marv