Three types of check strap were fitted to TR2-3B doors. The parts book does not make mention of a different part number for early and later cars, however by looking at the various applications we can make a reasonable assumption about where these changes occurred (this is only supposition on our part but seems to explain the different lengths and angle of strap).
The three types are as follows: -
Straight long type: TR2 long door
Straight short type: TR2 short door to TR3A up to commission number 60,000
Angled long type: TR3A/B after commission number 60,000
Long door TR2 s would not have the restriction of the outer sill inhibiting full door opening as there isn t one so it seems reasonable that the long straight part was fitted to these cars.
When the short door was introduced an outer sill was incorporated. This outer sill has a pressing at the front where the lower forward edge of the door comes in when the door is fully open. This pressing does not go all the way in to the A post and would call for a shorter check strap. This sill continued up to the commission number 60,000 retool.
When the body shell was retooled at commission number 60,000 the outer sill was altered in the area where the lower forward edge of the door comes in when the door is fully open so that the pressing went all the way back to the A post, leaving more room for the door to open. We have concluded that perhaps as a consequence of customer complaints that the doors didn t open far enough, Triumph adjusted the sill at this retool point and provided a longer check strap (back to the long door TR2 length) to enable the door to open further. These later check straps are slightly cranked so that the rubber stop lines up with the angle of the door when fully open.
For reference the lengths between the centre line of the pin hole and the split pin hole are as follows: -
Short type 78.8mm (3.1")
Long type straight and cranked 92.3mm (3.6")