Hi Rob - pulled one of these buggers off the carrier today, struggle, struggle
sweat, sweat
to try and get some parts numbers for you. As ours were new everything was sealed up and would have been a major exercise to dissemble. So back to the manuals. They came with 2 types of bearings, ball and later plain due to shortages during the war. My parts manual only gives carrier part numbers and not the Ford numbers. However my Workshop and Maintenance Manual elaborated a bit. The track adjuster wheels are interchangeable with the bogie wheels after removal of the distance pieces necessary to accomodate the tapered stub front axles and the substitution of the distance pieces normally fitted to the bogie wheels. The manuals also tend to confuse the correct name for these wheels describing them as "track tension adjusting wheels", "track adjuster wheels" and the term idler is also used but this is also used for the small idler wheel. As I stated earlier I have several manuals, if you want photocopies let me know.
Nigel - the width of rubber on the bogies and track adjuster wheels is the same - 3".