Bill
I sometimes wonder if it would be a useful mod to put a viscous coupling in the drive to the "C" axle? That way it would give some slip for highway use, but still sufficient traction for most off-road applications.
Diana
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Bill
I sometimes wonder if it would be a useful mod to put a viscous coupling in the drive to the "C" axle? That way it would give some slip for highway use, but still sufficient traction for most off-road applications.
Diana
I am ignorant on the matter of LR 6wd, I was wondering why you couldn't do it like the bogey drive on trucks with drive for the rear axle coming out the back of the front diff, which also has a transfer type diff lock mounted above the front axle pinion, this diff operates like the LR centre (full time 4wd) diff and can also be locked, Regards Frank.
As Bill has posted many times, either of these options severely limit articulation. Not an issue on trucks...Quote:
Originally Posted by Tank
In the Perentie setup, the 'C' axle is only engaged when the difflock is activated. In other words, on the highway it is a 6x4, but with the front two axles engaged with a diff between them. While this is a little unconventional, it is a bit hard to see where you would need all axles driving but be concerned about the centre diff being locked.Quote:
Originally Posted by Lotz-A-Landies
John
THANKS F0R FIXING THAT UP F0R ME DIANA: N0 I'M N0T HAVING A 1END, THIS IS HARD T0 D0:MY KEYB0ARD IS FA11iNG T0 PIECES AND I'VE 10ST MY 0Hs, E11s, NINES AND FU11 ST0PS:
I'M ATTEMPTING T0 DESIGN THIS PT0 USING STANDARD THR0WAWAY C0MP0NENTS, BUT I'M N0T G0ING T0 BUi1D AN0THER 6X6 MYSE1F, JUST DESIGNING IT F0R S0ME0NE E1SE WH0 WANTS T0 BUi1D 0NE AND T0 KEEP THE 01D GREY MATTER ACTIVE:
I'M THINKING THE Mi1iTARY HAVE PR0BAB1Y G0T STACKS 0F THESE 6X6 DRIVES IN THEIR SPARE PARTS ST0CK AND WHEN THEY DISP0SE 0F THE TRUCKS AND PARTS THE DRIVES Wi11 SE11 F0R PEANUTS:
WAG00:
Ben, I've never looked under a 6x6 Land Rover, but if that pic on previous page indicates that there are 2 tailshafts, then the one to the rear diff would seem to be ridiculously long and I would imagine it would run above the front diff housing. That to me seems to be a limiting factor for articulation of both axles. Whereas the bogey truck setup found on most 4x2 trucks seems to work well on 6x6 military trucks, do you have a pic of the Land Rover 6x6 setup, would be interested to see, I did have a pic of a Ford F250 setup with bogey just like the trucks have and it was brilliant off road, will see if I can dig it up, BTW this is the first time I have seen Bill's posts on this subject, Regards Frank.
Bill,
Im no machinist but Im happy to make chips on the lathe for you if you send me bits and a drawing of what needs doing. Dont have a big lathe (12x36 in the old money) but its well big enough to throw landy gearbox components. I have tungsten carbide tooling and flood coolant.
S
The tailshaft to the 'C' axle has a centre bearing on top of the 'B' axle with an extra two U-joints and sliding joint. The diff on this axle is on the left rather than the right, and I doubt the drive is a limiting factor on articulation. This will be limited by the leaf springs, and will be somewhat larger than Series Landrovers which use the same spring, because of the rocking beam linking the springs on the two axles. However, the effective articulation will be a little less than it otherwise would be, because of the wider track.Quote:
Originally Posted by Tank
John
Perentie 6x6 articulation is very poor to say the least.But the long primary wheelbase,rear overhang, staggered offset rear diffs and ground clearance sapping underslung leaf springs suggest that cross country mobility wasn't very high on the designers priority list, rather than heavy, bulky load carrying ability
.The two piece propshaft with the centre bearing mounted high on the chassis is not condusive to good articulation either, and required that the front of the rearmost propshaft be fitted with a double cardan joint, that from experience with civilian Landy 6x6s, have a short service life.I would have thought that mounting the centre bearing on the axle tube of the leading rear axle, and splitting the angles between both propshafts, ala Studebaker and GMCs would have eliminated the need for the double cardan joint, in addition to permitting greater interaxle articulation, should a proper cross country suspension be fitted.
Even this arrangement doesn't give what I would call great articulation.
For example, even if the rearmost propshaft was fitted with 40 degree universal joints and it could be setup so that the U joints were straight with the vehicle on level ground, the most axle travel that could be had would be 13'' down and 13'' up. Assuming a static bumpstop clearance of say 6'' this translates to only 19'' of bogie articulation.Edit, thought about it some more and it should be able to get 26'', but the final 7'' of droop would be just the weight of the axle assembly providing traction, not an equal share of the rear vehicle mass..
The calculations are based on leaf springs keeping the axles parrallel throughout range of travel, an axle spacing of 39'' minus 13'' for the pinion length of a Salisbury diff, giving a propshaft length of 26''flange to flange, leaving a distance of around 22'' between universal joints.
The best drive arrangement for articulation, that still employed conventional axles i've seen was on the old Aus army AACO Internationals, with a vertical gear driven pinion mounted drop box on each rear axle. The propshaft u joints were almost straight, and the shaft was nearly as long as the axle spacing.
Bill.
Thanks for the offer S. I do have access to a lathe about 60km from here, but for the next month or so I will be very busy with bushfire prevention work on my property before summer, so won't be able to concentrate too much on the PTO until after then.Quote:
Originally Posted by roverrescue
Regards, Bill.