Vehicle transport, and belated introduction...

[john.k]

We drove dozens of trucks back from the sales down south......only serious incident we had was a guy in  4 ton Dodge sideswiped two of the trucks parked outside a motel just north of the NSW border......One Diamond T had the front axle ripped out and spun across the road way,the other Diamond T he hit the back and mangled the wheels and tyres and bent both bogie axles......Driver was a local and five times over the limit of those days ,which was .1,I think.......We were five trucks on one set of trade plates.....but the Queensland cops didnt even ask awkward questions.....must have thought we were civilian drivers moving army trucks....(they did have civilians moving their trucks about then.)

[Kraehe]

Hello John.k

Thank you for the tips, and correction about the fuel economy.  I don't know where I got the 1.1 km/L (3 mile/gallon) value.  I see the 1976 user handbook lists an average laden highway value of 2.5 km/L (7 mile/gallon) for the 4x4 models, and the 1971 handbook an average highway value of 1.77 km/L (5 mile/gallon) for the 6x6 models.  That you would expect even better than this is very encouraging.  Do you think the army was pessimistic in its reporting, or do the trucks now do better, perhaps, on modern fuels?  Or is it something else?

You have some great stories to tell, I see.  I somehow doubt that police today, however, would be as relaxed as those you encountered.  I've never noticed them to have much of a sense of humour at all... 

Thanks again.

Regards,

[Kraehe]

Hello Chazza,

If it had been me it would have happened in the middle of nowhere, late at night, during a raging thunderstorm, on a one way bridge, with traffic following and more waiting their turn on the other side.

Regards,

[Bluebell One-eight]

The figures in the handbook are " target" consumption. As Tpt supervisor for a few years one of the monthly tasks was calculating the fuel consumption for all the vehicles we had. 6 mpg for 4 X 4s and 3 for was close to average. The army ran them on standard grade fuel and it was noticeable that they went a bit better on super. So an unofficial trial running super and with the ignition timing advanced up to where Inter recommended the trucks returned 11 mpg at a steady 45 mph. So John's thought of better economy is quite real.  As for the relaxed constabulary back then it seemed to be everywhere. I once had to take an old Studebaker and water trailer out to a staging point for an exercise. The overnight stop was at the old CSL site on Camp Rd. It was Commonwealth property. The Studie had 6V electrics and the trailer 12v so no lights on the trailer. We put a Land Rover behind me and all was well till he dropped off. I kept going and was just starting to turn into CSL when I heard the sound of wheels locked up in the gravel and this car is heading straight for the truck's fuel tank. He missed some how and ended up about 10 metres past the truck. Next thing another car roared around the other side of the truck and blocked the other car in. It was a cop. He ran to the car and ripped the keys out then he came to the truck to see if I was OK... then said you're right he's pissed I've been after him for miles. I didn't need any encouragement to get the old Studie into the safety of Commonwealth property!   

[Kraehe]

Hello Bluebell One-eight,

Thank you for your comments.  Please note that I was not doubting john.k's information, just trying to understand the origin of the user manual figures.  What you have stated makes perfect sense. One would expect almost any vehicle perform better on higher octane fuel when tuned to use it.  It also makes sense that the army would tune the trucks to get by on marginal fuels; low octane and / or aged fuel may be the only fuel available in an area at war.  Did they do more that just retard the ignition?  Were the spark plugs the army ran of a hotter grade that used in International civilian trucks of the time?  Were there any changes to coolant flow, especially through the heads?

Another person with great stories!  Thank you for sharing.  Is there a thread where you chaps have written down some of these stories for posterity ?

Regards,

[Bluebell One-eight]

Back in those times the army called Standard grade fuel MT74 and super MT80. I assume the figures represented the octane rating, i.e. 74 and 80 octane. The actual octane at that time was about 90 for standard and high 90s for super. When the trucks sere new they could be wound out to 65 mph. Then about 1970 they came back from having mods done at the army workshops and you were lucky if you could ring a trucks neck to get 50 mph. Mind you the speed limit was 40mph then. I think the timing was the cause and it had more to do with slowing things down than fuel quality. As far as I know the engines in 4x4 trucks were the same as the civilian trucks apart from provision for the oil cooler. There were 3 engine variants, 281, 282 & 283. The 281 was a lighter duty engine used in smaller trucks. It had a single outlet exhaust manifold and single carby. The other difference was that it did not have sodium filled exhaust valves like the 282 &3. Incidentally the 2 piece manifold used in the Mk 4 and 6x6 trucks was available as an option on the civilian trucks in 1964. The same spark plugs were used, in fact if an engine is run with retarded timing it will tend to run hotter. Any one that served for a few years will have stories to tell, but like so many things in life time erases them. Perhaps admin could open a section for such tales!

[GGG]

I would respectfully suggest from my own experience with Mk3s and F1s that said mod must have happened post 1971 as we could wind both types up well over the placarded speed which I remember as 45 MPH. It did take longer with an F1 of course. Retarding the timing is not something that I would do but does fit in with the army mindset of the era. My late father-in-law worked for an engine reconditioner which did a lot of work for all three services. They often specified that diesels were to be derated by altering the valve timing but I don't remember him saying anything about petrol engines.
I hope that I am not starting a flame war.
Geoff O.

[Bluebell One-eight]

Hi Geoff, I don't think the retarding exercise was a listed mod, it happened when the trucks went in to workshops for some accumulated mods, the one where the air shifter replaced the bowden cables on the transfer case lever was one of them. The speed limit when I started driving was 40 mph for Mk3s ( and was the state limit for trucks) and 35mph for F1 &2s It was increased to 45 mph later. The retarding of the timing " mod" was probably influenced by location. Retarding valve timing happened a lot on US auto engines in order to meet emissions standards. You could buy timing gears or sprockets with more than one keyway machined into them to liven things up on a "smog" engine. i don't think the army would have done that because it would obsolete a lot of parts stock, and there was never any change in the RPS either.

[GGG]

I well remember on the course which was mid 1970 coming back to Pucka from a trip to Melbourne when our section's instructor was rostered as guard commander. He was going to be late anyway but when I got in for a turn to drive (an F1) I was told to keep up with the truck in front and don't look at the speedo. Those power dividers certainly sang a jolly little song once you got rolling. For the record he was late but in the way of such things someone covered for him. Even though I was a nasho I did have some good times in the army. I think that the driver's course was up there with the best. A good boss and good instructors and not too much spit and polish. Reminiscing ends.
Geoff O.

[Kraehe]

Hello Bluebell one-eight,

Thanks for replying, and the information on the different engine models. 

Here I thought the army was being clever and increasing the truck's versatility by retarding the timing, when really they just wanted to stop unauthorised speeding. Interesting that it wasn't a listed modification.  I guess they didn't want the troops to be able to change it back in the field.

I recall a "good" super in the late 70s / early 80s was said to be 98 octane (important to know for some of the higher compression motorcycle engines with which we played), and standard was much lower and variable.  The figure of 82 comes to mind, but I don't really know.

Time does indeed erase memories. I was always at my father to write down his memories of his WW2 airforce service, growing up in the depression, hopes and dreams when young, etc., but he did not. Now, all that is lost.  Imagine how much richer our culture would be if we all took the time to listen and really learn from our elders (and if they, of course, were willing to share).  So how do we get a story section started?  Who do we write to ask?

Regards,

[Kraehe]

Hello GGG,

Thanks for commenting.  I take it that the power dividers are a touch noisy.  I am told they are also the 6x6's mechanical weak spot. 

Is there anything that can be done to improve them?

Do you think they are problematic enough that one should steer clear of the 6x6s?

Regards,

[GGG]

Whilst noisy I never heard of the power dividers as a problem. It was alleged that the unis would disintegrate after long periods at excessive speed but I never experienced this. Retarding the timing doesn't just reduce top speed it reduces power something which neither truck, particularly the F1, had a surplus of. It also causes other problems so not something that I would recommend. You learnt about convoy interval real quick if you were following an F1 in a MK 3 on the open road once you came to a hill. The reverse was the case off road of course where the F1 was pretty hard to stop. I would have an F1 tomorrow but the lack of somewhere to keep it and the reaction of the prices justification tribunal rule it out.
I believe that many people bought Inters at auction and were disappointed with what they could do. The drive train was a bit light for (overloaded) civilian use. Mind you we see a lot of people on this forum who buy Land rovers and then try to make them into something that they are not.
Octane rating in that era was 87 for standard and 97, later 98 for super. At the risk of starting an argument I would suggest that running a vehicle on super when it will run satisfactorily on standard is a waste of money. Having said that I run my series 3 on 95 plus lead replacer. It doesn't make it go any better but it keeps Ethanol away from it, too much plastic in series fuel system.
I will now take cover.
Geoff O.

[Bluebell One-eight]

The things working against the power dividers are heat, speed and axle windup. All are interdependent. The faster the trucks are driven the hotter the dividers get. There is no way the windup in the drive train can be relieved when traveling on bitumen. The main cause is having tyres of different states of wear on the bogie. The windup increases pressure on the gear teeth surfaces in the dividers and this naturally increases oil temperature, higher speeds " multiply" the problem. The perfect way to cure the problem would be either a diff or lockable viscous coupling between the intermediate and rear axles. It would be a challenge. In real life speeds would need to be kept down, but not many have the patience or time to do that. Some of the modern additive for the oil may be worth looking at. It might be possible to make a system with oil pump and cooler to help too. A temp gauge on each divider would help too. If the left wheels were eased off onto the gravel shoulder, at intervals it might help relieve windup, but care would need to be taken with any following vehicles copping a spray of stones. Measure the circumference of the tyres by parking the truck on hard stand and mark the tyre with chalk and on  the ground and dive forward one revolution and check where the marks on the tyre are. If a wheel has rotated more that the others It is smaller than them. Small differences can be reduced by fiddling the tyre pressures, but don't go too far as it will cause heat build up in the tyre. If you have 2 pairs of tyres that are different in size then put the largest on one side of each of the axle that will make the diffs share the work. A temperature gauge would be the way to go if experimenting as you would  have a definitive record of what effect a change has made. A long winded reply, but probably a 4x4 will be less hastle in the long run if you will be traveling long distances.

[GGG]

Most interesting Bluebell One-Eight and I can see what you are getting at. I suspect that the army were more interested in off road performance than on highway. Of course as was discussed amongst the drivers that I worked with it was much more fun when someone else was paying the bills. I drove International transit mixers between trade jobs some years ago which had lockable third diffs. A different set up I know but also not designed for a lot of off road work. I used to dream about what an F1 would have been like with a turbocharged Cummins and a Road-ranger. Our boss was ex RACT so we had a few interesting chats.
Dinosaur rant ends.
Geoff O.

[Bluebell One-eight]

The cost factor would be at the top of the list, I would think. When the trucks were designed State speed limits for heavy vehicles were much lower than today, so what was perfectly adequate back then is marginal now. With the third diff many US military vehicles have them so they must work OK. Weight would have been another factor in the choice of the system used in the F1,2 etc. The fact remains that these trucks were brilliant off road. in the hands of a well trained driver