Aussie Thornycroft

[mammoth]

Re  engine mounts:-  4" square Australian hardwood would offer no flex whatsoever. There are 3 holes in the sub chassis at each of the four corner locations where those angle iron brackets could have been located. The top of the sub frame of mine sits just below the main frame. It appears there has been some mischief about both rear gearbox mounts on the subframe and I have deduced that there were fatigue cracks repaired by removal of offending portion of sub rail and a piece of formed angle iron inserted under, with a washer to pack it up to original level. On that thinking the engine mounts may have also cracked through, prompting the timber repair.

[mammoth]

I just remembered I have a copy of 'The Book of the Thornycroft" by "Auriga' sitting patiently on the shelf since 2006. As it covers the WD J model with M4 engine it is a useful reference to identify differences of the 2013 model variant. It also includes the faults which required re-design between 1914 and 1917. On the subject of engine mounts there was clearly trouble related to chassis flex which was addressed with the 3 point engine mount just described. However, this modification caused misalignment between crankshaft and gear input shaft causing various calamities including fractured crankshaft. The subsequent, and successful, modification was to mount the engine rigidly on the sub-frame which was then fixed at a central point only at the front. (similar to American practice at the time.)

[mammoth]

I have come to the conclusion that the identity of the early J type is very much tied up with the subsidy K type and with so little to go on I will start a new topic on the K type and invite comments, corrections or even shoot me down in flames when I have run away with speculation!

The Rod Dux book has been helpful while the Commercial Motor archive has helped to provide a general picture and a few faint images.

My J was sent to the Brisbane dealer W,F, Turk & Co from where  the trail goes cold. I have traced a previous owner who had it for about 30 years having purchased it from a deceased tractor collector who also had it for some time. The previously mentioned purchase of trucks by the Australian army occurred in Adelaide, Melbourne and Sydney, so being in Queensland mine missed the call up.

I am speculating that the chassis for both J and K types was identical and therefore features such as the raised rear cross members were common to both when they were only actually needed on one. (see the K type topic).  The K type  chassis differed by having the rear springs shackled front and rear.

 

In price lists the early J type was variously described as ; 3 ton; 75 cwt, charabancs chassis, the latter possibly having the M4 engine and was sold alongside the K type.

 

Edited March 25, 2021 by mammoth
typo and addition

[mammoth]

Sometimes you should look at what is right under your nose and indeed on Dave Rossington's prompt I looked on my shelf to find Vintage Commercial Vehicle magazine number 52 had an article  "Thornycroft J & K Types" written by  Bill Dawe who still resides in Ballarat, Victoria.

The information more relevant to the Subsidy K type and the transition to the WD J model I will post in that topic.

In brief, the 1912 'heavy range' comprised of the 2 ton C and 21/2 ton D model both with worm drive and L4 motor. The mysterious 4 ton H model was withdrawn before any were sold and replaced by the 33/4 ton J and 41/2 ton K aimed to meet War Office subsidy specifications.

The first J was chassis 1178 sold to J Wrigley & Sons in August 1912 and on display at the 1913 Olympia Show. 63 'J' were sold into private hands and the remainder to the War Office. From Chassis 1358 the M4 motor was appearing on some J chassis and the last one to have an L4 motor was 1382 dispatched on 16/1/14.

The  J and K chassis numbers were muddled up so takes some deciphering to tease it apart which Doug has been doing and has worked out that mine is the 41st J.

J K photos-001.pdf

Edited March 25, 2021 by mammoth
correction

[lynx42 Rick Cove]

J K Photos-001.

 

Edited March 24, 2021 by lynx42 Rick Cove

[mammoth]

catalogue J.pdfHere is the 1912 catalogue for J and K types.

Of note is the petrol tank under the seat with pressure feed to the carburettor

Edited July 25, 2021 by mammoth