I was a great believer in the improvement that the Eaton axle made to the performance of the motor although I often heard from some Drivers that they just didn’t bother to use the Eaton other than to pop it into “high” once they got going ! ■■■■■■■ Philistines I say ! 
Cheers Bewick.
Yrs ago we scrapped the kirkstall off fathers B series and put a big Eaton 2 speed under it came off a A series my uncle was cutting I think ,it was the one with the channel across the back that the shock absorbers went on to ? Cable operated and something like 96 plus mph on the tacho rollers .
Btw Denzil are there no repeats on T.V to nite 
Some years ago I worked with a company who ran Seddon rigids with the 6354T engines & the working two speed axle made a massive difference compared to the failed ones which had been wound into high.
I always found some drivers could use them and others just left them in high to avoid the jangling from the back end.
Dave…
dave docwra:
Some years ago I worked with a company who ran Seddon rigids with the 6354T engines & the working two speed axle made a massive difference compared to the failed ones which had been wound into high.
I always found some drivers could use them and others just left them in high to avoid the jangling from the back end.Dave…
That always bothered me, I felt as a fitter that the grating of gears when ‘split shifting’ must be causing damage. However a former test driver told me to make the main change on the box itself and then, just before releasing the clutch pedal, operate the two speed and it will change with no noise, make the change when in neutral…it took a little practice and it actually worked! I found the electric shifts better than the cable operated vacuum ones though, and then you had BMC’s etc where 4th high was actually a higher gear than 5th low which could catch you out the first time! If you went 4th low/5th low/4th high and then 5th high all was well.
Pete.
Both these trucks had Eaton 2 speed diffs the red one which I drove for the company had a 15 speed R/R and a 892 V8 Detroit the green truck I owned had a K19 ■■■■■■■ with a 13speed R/R and both were air operated change mechanisms.
Eaton recommended the ratio change was done with the truck statioary then rock the truck just to make sure both drive axles were engaged in the same ratio.
We did a lot of off road work in the oil and gas exploration industry so they were very suited to that work reliable but little cause to use on the highway.
Cheers Dig
windrush:
dave docwra:
Some years ago I worked with a company who ran Seddon rigids with the 6354T engines & the working two speed axle made a massive difference compared to the failed ones which had been wound into high.
I always found some drivers could use them and others just left them in high to avoid the jangling from the back end.Dave…
That always bothered me, I felt as a fitter that the grating of gears when ‘split shifting’ must be causing damage. However a former test driver told me to make the main change on the box itself and then, just before releasing the clutch pedal, operate the two speed and it will change with no noise, make the change when in neutral…it took a little practice and it actually worked!
Pete.
Not sure if it was the Right or wrong way to use it, I would move the switch then ease off the throttle pedal to allow a smooth change.
Dave…
Its just a pity that these great two speed axles dont exist anymore, I drove several motors that had them Plus a Dodge of my own, IMO They were the best thing from sliced bread,Of course like Dennis says some drivers couldnt use them they way that they were designed to be used, But as the old saying goes, Theres Drivers & Theres Drivers, And nowts changed as far as Im concerend 
, Regards Larry.
When I first past my test in 73 I worked for a company in Darley Dale Derbyshire, Toft Brothers and Tomlinson, they had a large fleet of lorries mainly Guy’s my first drive was a 4 wheeler Guy with 5 speed box and Eaton 2 speed back axle, I had this for about a week and then was given another one to drive which hadn’t got the 2 speed axle, first run with this one was to Birmingham around 60 miles each way a lot of which was the A38 dual carriageway, I made good progress but missed the 2 speed axle, it was only when I got back to the yard when the previous driver of this vehicle said, it flies doesn’t it!! I told him I missed the eaton axle, he replied, yep but they cant touch you once you get it into sixth!!! I found sixth the next day and he was right.
Steve
I’m not a fan of these axles. I found the air operated one fine without any issues other than it would blow your wig off. But the electrically operated ones were a PITA. With the exception of water ingress causing the selector to seize and the issue with a double drive bogie having one axle in high and the other in low the axle itself was usually trouble free, but the operating mechanism was a constant headache trying to keep the vehicles on the road. While not disabling the vehicle, one stuck in low at the other end of the country meant product was going to be late regardless of whether the vehicle called in to a dealer.
We had half a dozen of these poxy DAF FT1600 22ton tractor units. I wonder if anyone can identify from the pictures of the half shaft of the one in the link ,which is for sale, whether this is an Eaton unit or a DAF product. These FT1600s had a two speed double reduction axle. We had no end of trouble with the vehicles themselves and a fair share was to do with the 2 speed. In order for the speedo and more importantly the the tachograph to register correctly a ‘Triplex Box’ was required to change gear for the speedo drive. These failed regularly as did the system operating relay. At the axle end the change speed motor switchgear terminals were exposed to the elements so corroded or sometimes even the stud fell off. I can’t recall whether there was a spring inside the motor or not now at some 30+ years distance in time, but hazy memory seems to recall issues, the motors certainly simply burnt out and the worm seized. It wasn’t just the problem on the road which was annoying it was the lack of spares held by the dealers and the unfamiliarity of their fitters with the system which caused the most aggravation. Vehicles were off the road for days on end.
EDIT: Memory plays tricks, I had been thinking from the operator’s point of view. now I recall that if the spring broke it ended up with no drive and a disabled vehicle thus requiring an ‘inventive’ solution to get the vehicle to a workshop.
truck1.co.uk/used/tractor-u … 80231.html
I’ve used an Eaton 2 speed (4 wheel Seddon with a P6, and a 6 wheel Guy Warrior). I thought they were great bits of kit, treat 'em right and you had half a gear anytime you needed it.
I drove Seddon 13/4’s with the electric change and ERF LV 's with the air change and much preferred the air change none of the missed or rattling change of the electric or that could have been the inexprience of youth.Then I grew up and got a ■■■■■■■■■■■■■■■■■■■■■■■ much easier.
A regular check on the oil level in the motor was worthwhile and IIRC you only had to use light oil when topping the motor up. The Trader, D1000 and the Mastiffs had the electric change but for the life of me I can’t recall which type of change was used on our 180LXB Sed/Atks or the '72 ERF 6 wheeler flat we ran. 
Cheers Bewick.
I never encountered anything fitted with the air change, only vacuum on the BMC FFK’s/ FJ’s etc which were of BMC’s own make of axle anyway and not Eaton, and electric on Sed Ak 200’s and Mastiff/Boxers. The vacuum unit control cables used to stick or get out of adjustment. The Bedford two speed’s seemed trouble free as well. The speedo ratio change boxes could give problems, but not as bad as the ones used on the cable driven tachographs though! 
I never had to change a diff on a two speed axle, and can’t ever remember the change units giving problems either. However dad drove a BMC 701 seven tonner for Bootys Transport of Oxford and it got stuck between ranges in Trafalgar Square! Luckily there was a copper on point duty who got underneath, removed the plate from the change unit and wedged it into gear with a piece of wood to get dad on his way again as he was causing an obstruction!
Pete.
Had two Fords a D1000 on a J reg and a D1614 on a N reg both had the 360 turbo engine but the Jreg had Turner 5 speed box + 2 speed axle and the N reg a stright 6 box single speed axle . Both did well but the 2 speed axle J reg no hill was to steep never failed and a good top speed while the single speed axle did fail sometimes on hills thats doing livestock in the wilds of Wales
Well IIRC, The Dodge we had was an electric shift, (Red Button Type), To an Air valve on the Nearside of the chassis just in front of the axle, Never had any problems with it. The Bedford T K That I drove in the late 50s Had a vacuum operated switch, Of course the Braking System was just Vacuum, The two speed axle was way ahead of the T K s Non existing brakes, Regards Larry.
cav551:
I’m not a fan of these axles. I found the air operated one fine without any issues other than it would blow your wig off. But the electrically operated ones were a PITA. With the exception of water ingress causing the selector to seize and the issue with a double drive bogie having one axle in high and the other in low…
What happened then? Was there a cross-axle diff? Did it get a bit warm?
^^^^
It finds the weakest link and several factors determine what happens. Without a 3rd diff, unladen the best you can hope for is that one tyre will spin. Loaded, it either won’t move or if already moving something will fail: probably the intershaft between the axles. With a 3rd diff it will get hot, first to go will be the input oil seal although a worn - and generally they are worn - intershaft may fail 1st. What then happens is a race between oil starved input bearing and the 3rd diff gears and its spider.
Bewick:
I was a great believer in the improvement that the Eaton axle made to the performance of the motor
The logic goes along the lines why use a gearbox when we can ( try to ) use the diff to do its job.
The fact that they went to all the trouble of making 13, 16, and 18 speed gearboxes and you probably won’t find anything made with a silly two speed axle now answers the question.An ‘improvement’ it ain’t it’s just illogical thinking.
Carryfast:
Bewick:
I was a great believer in the improvement that the Eaton axle made to the performance of the motorThe logic goes along the lines why use a gearbox when we can ( try to ) use the diff to do its job.
The fact that they went to all the trouble of making 13, 16, and 18 speed gearboxes and you probably won’t find anything made with a silly two speed axle now answers the question.An ‘improvement’ it ain’t it’s just illogical thinking.
I don’t follow a logic which says that the 2 speed axle was illogical. Eaton even made a 3 speed axle although AFIK it was never available in the uK. I accept that particularly with an overdrive gearbox one ratio is more or less wasted , but the same is so with a splitter box or even some range change boxes with a splitter for the high range. In the '60s and early ‘70s the more or less standard tractor unit wheelbase was 9’ 6" although some models were even shorter. Propshaft angle is a necessary consideration for a chassis that short, a factor helped by the two speed axle allowing an increase in ratios form the more or less standard 6 but without an increase in gearbox length. The splitter boxes of the time were could be troublesome far more so than the two speed axle itself , some gained an unwanted reputation. Even the fabled Fuller gearbox was not exempt from significant issues with its range change and it subsequent development twin splitter was the subject of major modifications. It and the Spicer could easily be damaged by incorrect assembly, both were a trap for the unwary.
The Fuller gained popularity for two main reasons : it was compact and it offered a model capable of accepting the torque output of the more powerful engines coming on stream; something which David Brown could not match. This influenced the more conservative hauliers in their purchasing decisions along with the increasing ability to poach fitters with experience of Fuller overhaul.