gingerfold:
I always liked the Eaton 2-speed axle, in effect giving the same gearing as later splitter boxes, which the Eaton axle pre-dated. It was often referred to as a “booster gear”, and used correctly could transform the performance of a lorry with a standard 5-speed direct drive gearbox. Lazy drivers would keep the axle in low gear until reaching top gear in the gearbox and then engage high gear in the axle, giving an overdrive. The skilled, or keen, or enthusiastic driver would split every gear. The early vacuum operated rear axle switch could be slow to engage but the later electric operated switches were quicker to engage, although you could end up with a horrible noise from the back axle and no drive if you were too ambitious, as once happened to me with a Dodge 500 series with ■■■■■■■ V8. That had a 6-speed overdrive 'box and 2-speed axle.
Hi Gingerfold, This Dodge had a V 8 Perkins in along with a 6 speed box & the Eaton 2 speed, It was too fast, IMO my cousin who owned was forver relining the brakes, Regards Larry.
Yes, they were fast. I remember one hot August day morning going in to Brooke Bond Liebig in Stratford East London to load OXO cube essence in polystyrene containers for OXO at Great Harwood. It was so hot the essence would not set and it wasn’t until 4.00 pm that I got away. 32 pallets double stacked, sheeted and roped, 17 tons payload. I was doing a steady 70 mph all the way up the M1 with that Dodge, got home to Bolton at 8.30 pm. Fuel consumption 4.5 mpg.
windrush:
BMC used a vacuum shift cable operated and they were very hit and miss. My dad had one stick in neutral in Trafalgar Square driving a BMC 701 back in the sixties, a copper on point duty who had been a mechanic took the little plate off of the diff and wedged it into cog with a piece of wood to get him moving again! Later on they fitted an electric shift, much better. The most troublesome part was the speedometer ratio change gearbox really.
Pete.
All our BMCs were fitted with electric shifts, we also had Leylands Bedford TK with electric. The old Comet 90s & Bedford S type had a vacuum & the new BMC FJ had air shift, the electric was the best by far especially stabbing the clutch down changing on a hill.
Hey, In the heavy’s I only have experience with MB which was a very weak thing same as Volvo’s two speed.
Daf had the best two spead with few problems (think Eaton licence, or bought in parts).
All had the same problem the third and second highest were the same, so only one was useable.
But at that time Scania had with the splitter box in the 76/110 the same problem, 4H and 5L gave only a difference of about 100 revs.
IIRC the K1050 Dodges had an air change two speed - really quick change! With the 6.354 turbo, they were a quick motor in their day
The Commando’s had an electric change from memory, still quite quick but not a patch on the earlier ones…
My first boss had a couple of D1000 tractor units with ■■■■■■■ V8 and Fuller 8 speeds - all noise and not much go He then put a two speed axle in the one he drove! That made a vast difference - you could make a lot more noise, wear yourself out stirring the gear lever and flicking switches, and still not get anywhere fast
At BANBURY BRS 1967/8 Leyland super comets ,only one had the Eaton 2 speed, now that was something different to drive you kept changing gear all the time especially in a town only you knew the difference but it was good .that was if they let you drive it for a shunt even in the yard you would use the button sad or what.
I’ve been trying to remember when the 2-speed axle option went out of fashion. Popssibly mid-1970s, the last vehicles I recall with 2-speed axles fitted were Leyland Boxers when I worked for Mothers Pride Bakeries.
gingerfold:
I’ve been trying to remember when the 2-speed axle option went out of fashion. Popssibly mid-1970s, the last vehicles I recall with 2-speed axles fitted were Leyland Boxers when I worked for Mothers Pride Bakeries.
Dodge Commando’s still had them right up to the end in the late '80s so I would think you’re probably right - they would have gone out of fashion in the seventies
Eaton 2 speed on this 1980 D1114, used on drawbar work with mobile homes. He’s just off to the south of france solo in this photo.
Good quick motor,
Tony
IIRC A pal of mine had a K1050 Dodge and the two speed on this was Air & Electric, Electric switch on the gear stick and an air valve fitted on the near side of the chassis just in front of the axle, , Regards Larry.
Lawrence Dunbar:
IIRC A pal of mine had a K1050 Dodge and the two speed on this was Air & Electric, Electric switch on the gear stick and an air valve fitted on the near side of the chassis just in front of the axle, , Regards Larry.
Hi Lawrence
You’re spot on, I’ve got a K2413T Dodge and its electric selector in the cab and air operated actuators on the axles
For years I thought about double drives and 2 speeds and had though what a mess if one did engage and one didn’t then I realised must done on the first one ,I remember my uncle saying that by (swapping)changing one gear in the first diff of a double drive Guy made it a lot higher geared .
I was told years ago that a two speed axle on a double drive just wouldn’t work because the two diffs would be out of sync and spit teeth out if the changes weren’t simultaneous. I believed that to be true and it made sense. ------Until now. This has started me thinking again (never a good thing)!
Sir +:
I was told years ago that a two speed axle on a double drive just wouldn’t work because the two diffs would be out of sync and spit teeth out if the changes weren’t simultaneous. I believed that to be true and it made sense. ------Until now. This has started me thinking again (never a good thing)!
Well a pal of mine from Amble has a 6wheeler ERF With Eaton two speeds axles fitted, Regards Larry.
2-speed diffs in tandem drive wasn’t a problem, was called a 3-speed diff.
Eaton had a “how to change” plate affixed to the cab back in the day.
Driver would change one diff at a time, the 3rd differential takes care of the different final drive ratios.
Was a nightmare of confused ratios though when combined with a maker’s standard style main box. Much simpler to have a fixed final drive and sensible ratio choices in the main box.
Many of today’s big US and Aus built trucks run 2-speed diffs and use the main box for all gear changing. The low diff ratio can be used for extreme heavy starting off or in some cases simply as a max speed limiting device.
Common to find the select controls aren’t even in the cab, often mounted on the chassis.
If one diff fails to change ratio and is run like it for any length of time the third diff is going to (does) get very hot . The Leyland Constructor third diffs gave enough trouble as it was and they weren’t 2 speed. A three quid circlip broke allowing one of the gears to float on its shaft and before long the whole lot was scrap, unless the excess movement got picked up on service.
, Regards Larry.