Bigger tires...go faster?

#17
Fwiw, I went to 365/80R20 on my fast axel Unimog. I could go taller, but for my desired turing radius, mass, engine and driving needs, its about the maximum before diminishing returns.
They helped alot with its road driving and still plenty good off road, But I would be happier with a working group. Its lowest gear now is a bit tall if something needs a really slow creeping over without spilling all the ’pots & pans.
 
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#18
EU army trucks usually sit at 40mph in convoy, German truck speed limits are I think 40 on most roads as a max unless on motorway. .
EU (German) truck speed limit is 80 km/h (49.7 mph), but common speed is 90 km/h (56 mph) because that's what the truck speed limiters is set to ;)

A few trucks and buses will be at 100 km/h (62 mph) on motorways.

I travel at 80 km/h on highways in my 1979 MB L608 and is often overtaken by trucks doing 90 km/h. I find 80 km/h to be sufficient when on vacation, I'm in no hurry and want to relax.
 
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#20
That's great! Thanks for all the input Folks!

Grenadiers, I like that you've posted your max speed for other drivers

Sent from my Pixel 2 using Tapatalk
 

Sitec

Adventurer
#21
Sooooo, I learned of something here in Australia that might be a relatively cheep way of gaining more speed for us that need... I helped out a local MB mechanic who looks after a fleet of Mercedes Benz NG's, MK and SK's. He needed o rings and I had what he needed saving him a drive. Anyway, he tried to give me some $$$ for these O Rings, and I said 'nah, don't worry about that, you are my Merc Truck advise man'! He smirked and said no prob.. The conversation continued and we got around to the fact that my truck is flat out at just over 90kmh. I asked how much work it was to 'speed up' the HL7 axles I have... He said "a lot of work, you need a Joey Box". I'd never heard of a Joey Box before but a few years ago it was common to add a small in line 'Joey Box' behind the main box and in front of the rear axle to give older trucks a higher top speed, and also a low box if a 3 speed Joey was specified. I think I have got my hands on a Joey in exchange fore a carton of beer, so will keep you updated on the logistics of what ratio it is, how reliable it will be and the possibility of fitting it between my gearbox and transfercase.
Joey Box.jpg
 
#22
Sooooo, I learned of something here in Australia that might be a relatively cheep way of gaining more speed for us that need... I helped out a local MB mechanic who looks after a fleet of Mercedes Benz NG's, MK and SK's. He needed o rings and I had what he needed saving him a drive. Anyway, he tried to give me some $$$ for these O Rings, and I said 'nah, don't worry about that, you are my Merc Truck advise man'! He smirked and said no prob.. The conversation continued and we got around to the fact that my truck is flat out at just over 90kmh. I asked how much work it was to 'speed up' the HL7 axles I have... He said "a lot of work, you need a Joey Box". I'd never heard of a Joey Box before but a few years ago it was common to add a small in line 'Joey Box' behind the main box and in front of the rear axle to give older trucks a higher top speed, and also a low box if a 3 speed Joey was specified. I think I have got my hands on a Joey in exchange fore a carton of beer, so will keep you updated on the logistics of what ratio it is, how reliable it will be and the possibility of fitting it between my gearbox and transfercase.
View attachment 493690
Ha!
Here in ’Yankeeland it was referred to as ”Browniebox”.
 
#24
Simon

Never heard of one of these. I assume its permenantly in so it will effect all the gears and you may lose some of the lower ratios.

Interesting device.

I will watch with interest


Neil
 
#25
Simon

Never heard of one of these. I assume its permenantly in so it will effect all the gears and you may lose some of the lower ratios.

Interesting device.

I will watch with interest


Neil
No. I have one in my garage. It is a 3 spd gearbox. Ratios like 2.00, 1.00, 0.73, selected by a shift mechanism.
 
#26
Count me in on the interest in this. On a related note (the power for the different gearing), we have an OM366LA 204hp engine. Anyone know the difference between the 204hp and the 240hp variant? Is there any difference in the internals or is it just a larger turbo and injector settings?
 
#27
I like this idea. The only problem i can forsea on my vehicle is actually fitting it in . The shaft from my gearbox to transfer box isnt very long . Maybe 800 mm inc the universal joints. Doesnt leave much space.
Moving the transfer box back is doable but lots of work .

If it has a nuetral position then i would look to putvit between transfer box and rear axle as this device would only really be needed for 2 wheel drive on the highway.

In 4 wheel drive it could be set to nuetral and all would return to normal. If it has a nuetral.


Still watching

Neil
 
#28
If it has a nuetral position then i would look to putvit between transfer box and rear axle as this device would only really be needed for 2 wheel drive on the highway.
In 4 wheel drive it could be set to nuetral and all would return to normal. If it has a nuetral.
I think you really mean it to have a 1 to 1 ratio, rather than neutral.
Back in the day... I learned and drove one. It was a Ford 1960s F700 farmtruck.
Its 'Brownie was 3 speeds. Underdrive, one to one and overdrive. Dont remember it having a neutral. But it did have PTO coverplate.
 

Sitec

Adventurer
#30
Yes, from what I have gleaned in a few phone calls yesterday they are usually 3 speed, underdrive, direct drive or overdrive, and can be operated by a bowden cable or an air ram. The one I looked at yesterday was short enough to go between my gearbox and transfer case. The link shaft is only 610mm long but the boxes I've seen are less than that. Problem is the shaft faces on the gearbox output and transfer case input are about 100mm out of line! Link shaft.JPG
 
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