Good Day All
This W model Kenworth I owned had 56000lb Eaton 2 speed diffs,the front diff had a limited slip type diff centre which instead of planetary gears had large compression springs and packs of clutch plates, it was very good in off highway application for which I used it a lot in the exploration industry but it was advised not to change diff ratios on the run correct procedure being to stop operate the air control switch reverse up a few yards then drive off.
I guess into todays world of sensors there would have been a micro switch to tell you that both diffs were engaged in my world it was very much seat of the pants.
When manourvering i.e. reversing into say a jack knifed position the springs in the diff used to release tension with a loud clunk when driving forward again it used to scare the crap out of me, hence seat of the pants operation. lol
JIMBO47:
aye can remember my first time wae a two speed axle in a ford d series with a low loader(knock out axle),was used to 5sp d series& range change on a D series 6wheeler even tried a twin stick (Mack snow plough)…but what the hell was this !!!..drove round the block and back in tae ask the fitters to give me a clue ( sticker on the dash worn out,all i could read was two speed),one o the fitters told me what was expected with a smirk.
later on i drove a maggie Deutz it was a ZF 6sp with splitter but its sister wagon came with a two speed axle…fun fun …when you were dog tired and forgot which one you were on…wasnt quite the same ,i remember 1gear in particular was higher speed in low than when in high on the two speed.
hey Jimbo, that’s right with two speeds the Volvo was faster in 4th high as 5th in low. But at the same time the Scannies with all in the box was 8th and 9th the same and a step of over 500 revs to 10th,nice heavy loaded.
JIMBO47:
i remember 1gear in particular was higher speed in low than when in high on the two speed.
Those of us who had the pleasure of trying to earn a living with a Ford D1000/V8 will sympathize with you. It’s 6-speed ZF box & Eaton 2-speed had the same anomaly (today’s new word) whereby the sequence in the top of the box was 5th low, 6th low, 5th high, 6th high. When running a bit heavy (!) all of them were needed along with stacks of revs. But fuel was a lot cheaper in those days!
The most common truck I drove with a 2-speed diff was the 2-stroke Commer and with only around 100hp, splitting gears didn’t make a lot of difference to the end result.
Dropping down I’d just take the big steps to where it “pulled” and that was it.
Starting off was 2nd low then stagger up to top and then finally up into high range.
Using low range all the way through the box made maximum use of the shorter diff ratio.
Only bloke I know who did split them all had dropped a 6V53 into his Commer.
What a power giant for the day, almost 180hp !!!
JIMBO47:
i remember 1gear in particular was higher speed in low than when in high on the two speed.
Those of us who had the pleasure of trying to earn a living with a Ford D1000/V8 will sympathize with you. It’s 6-speed ZF box & Eaton 2-speed had the same anomaly (today’s new word) whereby the sequence in the top of the box was 5th low, 6th low, 5th high, 6th high. When running a bit heavy (!) all of them were needed along with stacks of revs. But fuel was a lot cheaper in those days!
Which engine did your D1000 have in ROF ? Mine was 1968 manufacture with the ■■■■■■■ V8/Turner 5 speed/Eaton 2 speed,I seem to recollect that Fords did use the 6 speed ZF but later on in the production run when they’ed dropped the ■■■■■■■ and were using the “Ford” badged Perkins V8.When I got the two Mastiff units 12 months apart in 1970 they both had the Turner 5 speed,but the later 28 tonner had the heavier Eaton IIRC it was the 1900 series but I’ll stand corrected as it’s a long while ago.Cheers Bewick.
Mine had the Perkins, Dennis. Four & a half miles per gallon and almost as much oil. I should have realised that it’s previous owner wouldn’t have wanted to sell it if there had been any mileage left in it! But it was the Custom Cab model so it had a chrome bumper, just like your noisy, uncomfortable (but economical!) Atkis.
an amusing tale about two speed axles . back in the 60s there was a small firm run by an old chap called billy higginson hauling coal from the derbyshire pits. he must have been in his 70s then , and didn’t like progress . his o type bedfords were worn out so he bought 3 or 4 new tk bed fords with 4 speed box and 2 speed axles . so far so good until billy took one for a test drive , came back with a face like thunder . " these lorries are far too fast , somebody will get killed " was his comment , pushed the two speed switch into low and sawed the cable off .
Two speed axles are something younger drivers know nothing about. They made a vast difference to lorries in the fifties to the seventies.
I drove several lorries withh two speed axles, and a few without.
The two speed gave you that half a gear that made all the difference.
The eaton two speed electric shift was the best of them,superior to the cable,air or vacuum changes.To change up lift the button,clutch down throttle up slight pause throttle down.To change down lift button before you want to change,clutch down and up as quick as possible without lifting the throttle.
This is the as fast a change as you will experience with any vehicle.
If the power to the motor failed or the shift motor failed we used to remove the cover from the motor,screw it into high jam it with a block of wood and refit the cover.This would get you home.(as the song says.those were the days my friend).
The mechanic:
If the power to the motor failed or the shift motor failed we used to remove the cover from the motor,screw it into high jam it with a block of wood and refit the cover.This would get you home.(as the song says.those were the days my friend).
When my dad’s two speed stuck in neutral in Trafalgar Square in the '60’s a bobby took the plate off and jammed some wood in to get him shifted!
Used to drive BMC FJ’s and FFK’s with two speeds but the vacuum shift was very “hit and miss”, we had some Sed Ak 200’s at the quarry in the 1980’s with electric shifts and they were fine.
I drove a Bedrord KM in 1970, just used to to pull the button up ease the throttle to change up, the axle change went smoothly without touching the clutch peddle, never had no trouble, as you say eaton, good kit.
I had one on a KM & one on a Sudden Accident, the KM was ok but the other heap of junk had a Gardner & it took so long for the revs to die down when changing up that by the time the change went through I’d lost all speed so I didn’t need the change! Good piece of kit though, it made that KM go well.
Your right Dave there was no need to use the clutch but if you did it took pressure of the drive and ensured a smooth change for those of us who were less skilled in the art of changing.
I also drove a Commer maxiload and a BMC ffk 140 with two speeds, as you say , the Km,s would go with the 466 engine, only lorries to keep with them were the ford d series with the turbo. The Commer with the TS3 was a good lorry.
dieseldog6:
On the ford D series I had and the V8 Mastiff (wow) my Brother drove, 4th with the button up was an higher gear than 5th with it down.
Yes we had a Mastiff like that! Caught me out well and truly when I drove it one day, changed up and the revs increased! The regular driver used to go from low 4th to low 5th, back to high 4th and then high 5th (top), it went really well for a 16 ton 4 wheel tipper! A proper Clydesdale gobbler
If you view LK44 in the photo forum you will see the ERF that Iowned and restored.This had an eaton two speed and you could split change,but as in the mastiff it was 4th low 5th low 4th high and then 5th high.Most of changes worked out about half a gear but 4th high only gave you 2-3 mph more than 5th low. Changing down you were better going from 5th high to 4th high and then split change downwards.
With the Bedford KM I used to go from high 4th to low fifth and definatly gained on some of the other lorries on the lesser gradients. You may not believe me Robert, but I could put one over on the boys that used to scalp me when I was on a Dodge K series with a perkins 6354. Perhaps I didn,t know how to drive the Dodge. Ha Ha.
Good Day All
