When L.T. was being criticised for not being able to keep on top of the maintenance of DMS,
Tomorrow's World devoted most of a programme to them. What a coincidence and it almost seemed like the presenter had been coached by L.T. Surely not, the BBC is independent.
The presenter was standing by one in a workshop and said 'L.T.'s overhaul process is very thorough and involves separating the bodies from the chassis. With these provincial buses it's impossible to do that'. What he didn't explain was why 'provincial operators' had given up separating body and chassis at overhaul in the mid-50s and it had been done mainly because bodies were then composite and took longer to overhaul than chassis. Once 'all-metal' bodies became standard, there was no need.
It puzzled me that, in the L.T. body/chassis separation overhaul the engine and auxiliaries were left in the chassis, which was jet washed and steam cleaned (hope they banked off all the intakes and vents). Engine changes were on a different cycle, and were done physically at garages but by a team that turned up (from Aldenham, I think) in a special van with a built-in engine crane and a replacement engine.
But of course DMS were totally unsuitable for the arduous L.T. demands (e.g. Potters Bar town service) but perfect for 'The provinces' (e.g. Birmingham's Outer Circle running in heavy traffic for 18 hours a day)
The objection to DMS body removal - or rather, refitting to. a different chassis - was,I understood at the time, that the body mount locations were not jig built so the holes might not line up.
Northampton Corporation /Transport had standardised on Gardner engined daimlers for years. For OMO they ordered Daimler Fleetline single decks with, naturally, Gardner engines. Daimler unilaterally changed the spec to Leyland engines so that L.T. could have the Gardners for DMS - there was a shortage of 6LXs. The CRG6Ls that came suffered engine problems lost the Gardner reliability..