HD11EC

My Dad had an 11ec in 1975 he worked it till he passed away in 1995 and then I worked it until 2009 , other than an engine overhaul kit and a few track rollers that tractor never gave any trouble it was very reliable and good on fuel , I sold it to a bloke in 2009 and in 2011 he passed away the tractor was caught in flood waters up to the floor platform and sat in water for around 3 months like this then it was sold at auction the new owner changed all the fluids and the machine is working well still! the new owner had to pull the right hand steering clutch out and found it was full of grease as a pipe was broken of and when it was greased over the years was filling this compartment up

10000 series engine, long track frames with 7 rollers each side, power steering , 3 forward speeds and 2 reverse ,

HD11EC had a 3F 2R manuel shift transmission, with a torque converter and master clutch. They were quite popular up until the introduction of the powershift HD11EP but after that there was no real purpose for it. people wanted either powershift or direct drive; so it was deleted from production by 1967.
From accounts from a lot of different people they were a troublesome tractor. The one failing I have heard of a lot was they snapped the end off the final drive main shaft, right on the end where the track frame connects. This is abit of a common AC fault, have seen it on HD6s; but 11EC was notorious for it. Think it was the combination of the massive torque multiplication of the twin disc converter coupled with the low speed gearing of the 3 speed trans. Just too much push power especially once the tractor got 'under' a load and the blade could add more weight to the tractor and hence more traction. The live axle couldn,t take it.
As a comparison speed in 1st gear on a 11EC was 2.4 mph. On a 11EP it was 3.3 mph in 1st. Both used the same converter with 4.6-1 multiplication.
They are certainly a rare tractor to find, have only ever seen one here.