Bking:
Retired Old ■■■■:
Bking:
Do you mean the twin splitter? Never really got on with those too “faffy” but the 9 or 13 speed Eaton fuller gearbox with the square box change was a joy to drive.Could outshift any crap syncroed unit once you got the feel of it.Another good box was the Spicer with overdrive but they tended to chip teeth if you were a bit rough with them…Use to love repairing them nearly as much as driving them.Real truck gearboxes even the old crouts used to fit them in MANs rather than the usual ZF rubbish.
Main reason they died out was that there is no way you can link them into an electronic or semi automatic shift system.Like a motorbike you have to match engine speed with road speed and no super dooper ECU can beat a human being at that.Even the split had to be timed right never mind the range.But you could beat any syncro box truck off the line because you actualy shifted the gears not the syncro hubs.Memories!
Remember I once rebuilt a Spicer and got the counter shaft timing wrong.Started the old sedack up all was fine went to get a brew while it was ticking over on the pit,came back and a very strange noise but just was not quick enough to turn the motor off before the gearbox exploded. [zb] Awesum like putting a grenade in a biscuit tin.All that was left was a bit fastened to the prop and the front of the box and bell housing.OH [zb]If I may be allowed to jog the memory a bit- Eaton DID actually bring out a semi-automatic box using the twin splitter as a base. They had a working mock-up at a Commercial Motor Show in the 1980s and both my workmate and I had a go on it. As long-time users of the Roadranger series, we found the semi-auto box a brilliant piece of kit to use, although I believe it never got into production due to cost and weight. Eaton also had a mock-up of a semi-auto version of the Roadranger 9-speed, but I assume that went the same way, for the same reasons.
To return to the original question, I thought the twin splitter (or more correctly, the twin countershaft) gearbox was, and still is, the best thing since sliced bread. But then, I was brought up on “decent” gearboxes without namby-pamby things like synchromesh or electronics.ALL Eaton heavy transmissions are twin counter shaft,single input dual output.Only real difference between the twin split and the fuller was 2 torque springs and a logic box.The twin split was really the begining of the end for the crash box.It sowed the seeds of its own destruction.
There was a automated version of it offered called SAMT someone here had a thread going on here about it I think they done an article about the early automated boxes for a magazine. Newmercman had an Iveco fitted with it. Was quite troublesome so was retrofitted with a standard twin splitter