LHD Bollekens cabbed Mk V AECs

ERF-NGC-European:

tiptop495:

ERF-NGC-European:

ERF-NGC-European:
Reading back through this thread it occurs to me that at no point is the the actual version of the TET (Thornycroft) constant-mesh 6-speed 'box mentioned. It was probably the D203 in the Belgian Mk5 unit. The D236 and D250 might have been a bit later (and the final D273 presumably too late). Can anyone confirm which version was fitted?

Ro

I think I’ve found the answer to my own question. I asked a similar question on the AEC V8 thread a long time ago and ‘ERF’ replied with his usual wonderful detail and insights as follows (in italics):

The basic 6-speed o/d gearbox available in the AV760 Mandator was the TET D203 with it’s 1-3/4" input shaft. This, at 615 lb-ft, had a design torque capacity very slightly higher than service torque capacity of the ONLY Fuller Roadranger in production in the UK in 1968, the RT and RTO610. Both were designed for use in service with engines developing up to 600lb-ft torque.
To fit the D203 to the V8 engine required an extended selector housing to allow the change rod to clear the RH cylinder bank. This modified gearbox was designated the D236 and it was fitted to all Mandator V8’s from the start of production until early in 1969.
When the higher output AV800/801 powered V8’s were produced, TET increased the torque capacity of the D236 by beefing up the front end bearings and fitting a 2" input shaft. This gearbox was the D250, and it was fitted to all subsequent V8’s that had the 6-speed gearbox option, including the AV740’s.
Higher capacity 6-speeds were already on the drawing board at TET in 1970, and some of these would go on to be used by Guy in the Big J, AEC/Leyland in the Marathon (behind the L12 engine) and by Scammell in the Routeman, Handyman and Trunker.
By 1976 the last version (to the best of my knowledge) of the old 6-speed was being produced, by this time Eaton had taken over at TET, and this gearbox (still with a 2" input shaft) featured needle roller bearings on the mainshaft gears (as opposed to the bronze bushes of the D236 and D250), higher torque capacity gears and taper roller bearings (as opposed to roller bearings) on the mainshaft and layshaft. This gearbox was the D273 and was a Scammell option right to the end of Routeman production.

Hey, some had ZF boxes.

Eric,

That’s interesting. Would that have been the AK-80 six-speed constant-mesh one?

Hey sorry a late answer.
Not sure but think for engines for around or plus 200Hp, was most the ZF AK 6-90 used.
Or the twelf speed ZF AK 6-90 - GV80.
I will look in mij brochures and spec sheets if something is mentioned.

Eric,