I have a Commer 6 Speed Gearbox and I would like to know what type of oil is recommended for it and how much oil it takes. A workshop manual would be fantastic too, and I’m happy to pay.
Can anyone help?
Thank you for replying.
All I really need from here is the quantity of the oil to refill the gearbox.
I did mention a manual but it’s not essential and even if I had a problem with my gearbox I’d get a specialist to look at it.
The manual I have to hand says 20 pints (11.4 litres). This is for the 5 speed. The 6 speed is just a small bit on the back of the 5 speed so I would say another couple of litres. Doesn't matter because, like all gearboxes and diffs the filler hole is the correct level.
Some truck boxes had aluminium synchros,maybe this is why.....so you could use diff oil........I know the theory with truck fleets used to be. to have only diff oil in stock......so its impossible to use the wrong oil in a diff....Roadrangers are supposed to use engine oil,but you smell diff oil in plenty of them..............My gripe about EP diff oils is they actively corrode steel if water/condensation gets into the box.
Probably worth reading that article if you are going to keep the Commer for a long time.
These are an outstanding gearbox and a complete no-brainer to drive. Although most people double clutch out of habit you can drive them like a Toyota Corolla just pushing them through either up or down on the synchros smooth as silk.
They are at least as easy to drive as the old Volvo 4+4 synchro boxes from that period but neither is as much fun as a Road Ranger
The Commer 5 speed box is a near exact copy of the IH T35 ,on a slightly larger scale...The OD is just added on to the back end,in the same way as many pommy truck boxes were.The IH box has alloy synchros ,so I wouldnt be surprised if the Commer box does too...........Ive got a Commer box with the lid off ,might have a look.