6-wheelers (offroaders and lorries) and transmission wind-up?

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
I

Ian Rawlings

Guest
Hello peeps, it looks like I've fallen in love with a beautiful
swedish model who is incompatible with my landrover, so am likely to
be selling it at some point so she can move in. Once she's settled in
I will get a non-threatening series 1 80" that's been on the cards for
a while.

She has six wheels, the rear four of which are driven permanently with
the front pair driven only when engaged off-road. There is no diff
between the two rear axles, just a solid shaft, with the axle centres
being about a metre and a half apart. I thought that I'd ask you
chaps about opinions on this, and if six-wheeler lorries are set up
the same way.

It appears that this setup is fine as the reputation for reliability
of these machines (Pinzgauer) is rock-solid, so I can only assume that
the wind-up between these two axles is minimal due to them being so
close together, and there are chances for wind-up to be relieved while
the twin rears are slipping sideways during tight corners.

So any thoughts on this? It'll be at least 6 months before the landy
goes up for sale, if I don't have a change of heart in the meantime.

--
Blast off and strike the evil Bydo empire!
 
On Thu, 30 Mar 2006 11:49:23 +0100, Ian Rawlings
<[email protected]> wrote:

>Hello peeps, it looks like I've fallen in love with a beautiful
>swedish model who is incompatible with my landrover, so am likely to
>be selling it at some point so she can move in. Once she's settled in
>I will get a non-threatening series 1 80" that's been on the cards for
>a while.
>
>She has six wheels, the rear four of which are driven permanently with
>the front pair driven only when engaged off-road. There is no diff
>between the two rear axles, just a solid shaft, with the axle centres
>being about a metre and a half apart. I thought that I'd ask you
>chaps about opinions on this, and if six-wheeler lorries are set up
>the same way.
>
>It appears that this setup is fine as the reputation for reliability
>of these machines (Pinzgauer) is rock-solid, so I can only assume that
>the wind-up between these two axles is minimal due to them being so
>close together, and there are chances for wind-up to be relieved while
>the twin rears are slipping sideways during tight corners.
>

Its the usual way to do 6x6, as the axles are close enough together
that there is minimal windup between them. The commercial side tends
to do it by having a pass-through mid axle, which has an extra output
from the back of the diff, with a short prop linking to the rear axle.
The amount of difference between the two axle speeds is negligible,
the main difference when going round corners is experienced between
the front axle and the rear pair, especially as the front axle has two
wheels both turning at different speeds when going round a corner. The
only downside can be a tendancy to wear out the tyres on one of the
rear axles quicker than the other, but this is usually only
experienced in vehicles which have 6x4 or selectable 6x6/6x4/6x2.

Alex
 
On 2006-03-30, Alex <[email protected]> wrote:

> The commercial side tends to do it by having a pass-through mid
> axle, which has an extra output from the back of the diff, with a
> short prop linking to the rear axle.

That's the way the Pinz does it, I'd imagined that it would have a
selectable transmission link similar to the one between front and rear
axles giving it two wheel drive on the road, but I couldn't see it on
the chassis between the rear axles so looked into it.

> The only downside can be a tendancy to wear out the tyres on one of
> the rear axles quicker than the other, but this is usually only
> experienced in vehicles which have 6x4 or selectable 6x6/6x4/6x2.

Pinz has selectable 6x4 and 6x6 with cross-axle diff lock on all axles
(rear two are locked together, front can be locked independently).
I'll check up on tyre wear but I don't think it's going to be an issue
worth fretting about.

Cheers for the input.

--
Blast off and strike the evil Bydo empire!
 

>The commercial side tends
> to do it by having a pass-through mid axle, which has an extra output
> from the back of the diff, with a short prop linking to the rear axle.

No the front drive axle has a inter axle diff (lockable) and lockable diffs
in each drive axle


> The amount of difference between the two axle speeds is negligible,
> the main difference when going round corners is experienced between
> the front axle and the rear pair, especially as the front axle has two
> wheels both turning at different speeds when going round a corner. The
> only downside can be a tendancy to wear out the tyres on one of the
> rear axles quicker than the other, but this is usually only
> experienced in vehicles which have 6x4 or selectable 6x6/6x4/6x2.
>
> Alex



--
Andy

SWB Series 2a ( dressed as a 3) "Bruce"
It's big, it's mean it's really, really green


 
On 2006-03-30, Andy.Smalley <[email protected]> wrote:

>> The commercial side tends
>> to do it by having a pass-through mid axle, which has an extra output
>> from the back of the diff, with a short prop linking to the rear axle.
>
> No the front drive axle has a inter axle diff (lockable) and lockable diffs
> in each drive axle

I think what Alex was saying was that on most six-wheeled commercials,
the first rear axle has a "pass-through" diff on it, in that it takes
power in from the front and then passes it through to the second rear
axle. The pinz also has this, but adds front-wheel drive and lockable
cross-axle diffs to the equation, which is what you're saying.

In summary though, it seems to be a common layout and I don't need to
fret about transmission wind-up between the two rear axles under
normal road-going conditions.

--
Blast off and strike the evil Bydo empire!
 
As an owner operator of volvos, scanias and fodens with the configuration of 6x4 and 8x4's, I can tell you with complete confidence that the first of the rear drive axles has an intermediate diff on the front. The drive is taken off the propshaft and distributed to each diff seperately, much like your centre diff on a landrover discovery or rangie. That is complete with a diff lock incase one axle starts to spin leaving the other standing i.e. one set of wheels out of the four could be spinning whilst the other three are standing.
Each axle has its own diff lock aswell to lock all drive together. Without the intermediate diff on the front drive axle, you would have severe wind-up and tyre wear. I know this because I have had to take an intermediate diff to bits when it jammed and then got driven home. I would say the Landrover would have a similar setup on its two back axles, otherwise you would suffer with the same problem.
 
On or around Thu, 30 Mar 2006 11:49:23 +0100, Ian Rawlings
<[email protected]> enlightened us thusly:

>She has six wheels, the rear four of which are driven permanently with
>the front pair driven only when engaged off-road.

git...
--
Austin Shackles. www.ddol-las.net my opinions are just that
Beyond the horizon of the place we lived when we were young / In a world
of magnets and miracles / Our thoughts strayed constantly and without
boundary / The ringing of the Division bell had begun. Pink Floyd (1994)
 
On 2006-03-30, Austin Shackles <[email protected]> wrote:

> On or around Thu, 30 Mar 2006 11:49:23 +0100, Ian Rawlings
><[email protected]> enlightened us thusly:
>
>>She has six wheels, the rear four of which are driven permanently with
>>the front pair driven only when engaged off-road.
>
> git...

Did I mention the three cross-axle diff-locks?

And the build quality?

Costs the same as a decent second-hand Defender, about £8k. Yum.

Parts costs on the other hand.....

--
Blast off and strike the evil Bydo empire!
 
Ian Rawlings wrote:

> On 2006-03-30, Andy.Smalley <[email protected]> wrote:
>
>>> The commercial side tends
>>> to do it by having a pass-through mid axle, which has an extra output
>>> from the back of the diff, with a short prop linking to the rear axle.
>>
>> No the front drive axle has a inter axle diff (lockable) and lockable
>> diffs in each drive axle
>
> I think what Alex was saying was that on most six-wheeled commercials,
> the first rear axle has a "pass-through" diff on it, in that it takes
> power in from the front and then passes it through to the second rear
> axle. The pinz also has this, but adds front-wheel drive and lockable
> cross-axle diffs to the equation, which is what you're saying.
>
> In summary though, it seems to be a common layout and I don't need to
> fret about transmission wind-up between the two rear axles under
> normal road-going conditions.
>

This set up is used on some 'on-road' six wheelers but many have a 'power
dividers' or centre diffs between them, usually integrated with the forward
rear diff. I have been involved with both and the one without the diff is
certainly less trouble prone. Transmission wind up is in itself no problem
(if considered at the design stage) and is much lower than with a 4x4
because the two axles are a lot closer, and is resolved simply by tyre
slip, with resulting higher tyre wear - but a six wheeler drags the wheels
sideways when turning anyway, so it probably does not make much difference.

It is of interest to compare these two options with the 'perentie' Landrover
110 6x6 which 'normally' drive the front two axles with the usual centre
diff, the third axle trailing. Engaging the centre diff lock also engages
drive to the third axle by a separate shaft from the PTO designed for the
powered trailer on the 101. This is carried by a centre bearing on top of
the middle axle to the diff offset to the left rather than right.
JD
 
On Thu, 30 Mar 2006 19:23:35 +0100, Ian Rawlings
<[email protected]> wrote:

>On 2006-03-30, Austin Shackles <[email protected]> wrote:
>
>> On or around Thu, 30 Mar 2006 11:49:23 +0100, Ian Rawlings
>><[email protected]> enlightened us thusly:
>>
>>>She has six wheels, the rear four of which are driven permanently with
>>>the front pair driven only when engaged off-road.
>>
>> git...
>
>Did I mention the three cross-axle diff-locks?
>
>And the build quality?
>
>Costs the same as a decent second-hand Defender, about £8k. Yum.
>
>Parts costs on the other hand.....

A lot of the suspension and brake components will be commercially
available. The engine will be something readily available to the
commercial market, you just have to find out what else it was fitted
to and go to a commercial motor factors armed with part numbers and
vehicles.

A bit trickier to get parts for, certainly, but if you use your noodle
you can save significantly.

Alex
 
On Thu, 30 Mar 2006 19:23:35 +0100, Ian Rawlings
<[email protected]> wrote:

>On 2006-03-30, Austin Shackles <[email protected]> wrote:
>
>> On or around Thu, 30 Mar 2006 11:49:23 +0100, Ian Rawlings
>><[email protected]> enlightened us thusly:
>>
>>>She has six wheels, the rear four of which are driven permanently with
>>>the front pair driven only when engaged off-road.
>>
>> git...
>
>Did I mention the three cross-axle diff-locks?
>
>And the build quality?
>
>Costs the same as a decent second-hand Defender, about £8k. Yum.
>
>Parts costs on the other hand.....

BTW, I take it you've bought an older one, about 1975-1979 if you paid
£8k.....

Alex
 
On 2006-03-30, JD <[email protected]> wrote:

> I have been involved with both and the one without the diff is
> certainly less trouble prone.

Cheers for that, useful info. The pinz is an old design, around the
series 2 landy era, nothing advanced.

> It is of interest to compare these two options with the 'perentie'
> Landrover 110 6x6 which 'normally' drive the front two axles with
> the usual centre diff, the third axle trailing. Engaging the centre
> diff lock also engages drive to the third axle by a separate shaft
> from the PTO designed for the powered trailer on the 101. This is
> carried by a centre bearing on top of the middle axle to the diff
> offset to the left rather than right.

I've read about a number of different solutions to the 6x6 landrover,
the above seems like a good solution especially if you consider the
issues of having a rear set of four driven wheels joined by a fixed
shaft, with the front joined by the differential. You'd end up with
the rear four getting half the engine's torque and the front two
getting the other half. Probably easier just to do the above!

The pinz on the other hand doesn't have a diff between the front axle
and the rear axles, just a series landy-style selectable link. It is
a 1970's vehicle after all. The four-wheel pinzes are two-wheel-drive
on the road.

--
Blast off and strike the evil Bydo empire!
 
>> It is of interest to compare these two options with the 'perentie'
>> Landrover 110 6x6 which 'normally' drive the front two axles with
>> the usual centre diff, the third axle trailing. Engaging the centre
>> diff lock also engages drive to the third axle by a separate shaft
>> from the PTO designed for the powered trailer on the 101. This is
>> carried by a centre bearing on top of the middle axle to the diff
>> offset to the left rather than right.
>
>I've read about a number of different solutions to the 6x6 landrover,
>the above seems like a good solution especially if you consider the
>issues of having a rear set of four driven wheels joined by a fixed
>shaft, with the front joined by the differential. You'd end up with
>the rear four getting half the engine's torque and the front two
>getting the other half. Probably easier just to do the above!
>
>The pinz on the other hand doesn't have a diff between the front axle
>and the rear axles, just a series landy-style selectable link. It is
>a 1970's vehicle after all. The four-wheel pinzes are two-wheel-drive
>on the road.

Good movie of the current generation Pinz on Stewart&Stevensons
website (Uk importers/dealers/MOD suppliers)

http://www.pinzgauer.uk.com/user_files/video/Pinzgauer.wmv

Alex
 
On 2006-03-30, Alex <[email protected]> wrote:

> BTW, I take it you've bought an older one, about 1975-1979 if you paid
> £8k.....

I've not bought one yet, and won't do for about 6 months at the very
least, I need to rustle up about £4K first then flog the landy for
about the same. I've got enough loot in the bank to buy it and keep
the landy at the moment but that's an emergency fund in case business
plans go wrong, very tempting to blow some of it!

I drove one on Wednesday, a 1973 model, in top-notch condition. It
was bought by a company who make armour for vehicles, they were going
to use it to develop armour for the pinz but Pinzgaur UK found out
about it and sent them a brand new model for free, which they promptly
blew up...

For a 1973 vehicle, it was absolutely immaculate, real quality
metalwork, dry as a bone underneath, the floor of the garage where it
had sat for four months without moving was clean as a whistle.

--
Blast off and strike the evil Bydo empire!
 
On 2006-03-30, Alex <[email protected]> wrote:

> A lot of the suspension and brake components will be commercially
> available.

The springs and shocks might be shared between other vehicles, but the
rest of the suspension isn't. Cheap bits are likely to be common
between other vehicles, it's the bigger metalwork that's serious cash,
unsurprisingly. Inside the brake drums is likely to be pretty common
stuff. It's not bank-breaking stuff though, mostly perhaps 50% more
than the equivalent bits for the landy. Hard to get second-hand though.

> The engine will be something readily available to the
> commercial market, you just have to find out what else it was fitted
> to and go to a commercial motor factors armed with part numbers and
> vehicles.

The engine is a specially-designed air-cooled straight four 2.5 litre
petrol, it uses common carbs (either stromberg or webber, can't
remember). The newer machines use a specially-designed diesel,
however it was designed by VW so probably looks quite familiar.

All spares are apparently available for the vehicles, some
re-manufactured as is common with vehicles of this age, old landies
and old lotuses are similar. There might be some parts that you can't
get any more, usually small parts that you throw away then realise
that you can't get any more ;-)

--
Blast off and strike the evil Bydo empire!
 
On 2006-03-30, Alex <[email protected]> wrote:

> Good movie of the current generation Pinz on Stewart&Stevensons
> website (Uk importers/dealers/MOD suppliers)

Yeah, not bad. For £8k you can get the same machinery just with an
engine that's got half the power, a manual 5-speed instead of an auto
four-speed, no power steering and drum brakes instead of disc. I
reckon that's good value for money. The six-wheeler is about a foot
longer than a 110 and about the same height. You can probably tell
why I'm interested, it's got the charm of the series landies too.

--
Blast off and strike the evil Bydo empire!
 
Ian Rawlings wrote:

> I drove one on Wednesday, a 1973 model, in top-notch condition. It
> was bought by a company who make armour for vehicles, they were going
> to use it to develop armour for the pinz but Pinzgaur UK found out
> about it and sent them a brand new model for free, which they promptly
> blew up...

Sounds familiar - the NZ Army have recently bought a load of Pinzgauers,
all of which started suffering from terminal problems and most of the
fleet has been parked up since pending a factory modification. Still,
it means there's about to be a load of Stage 1's for sale :)


--
EMB
 
On 2006-03-31, EMB <[email protected]> wrote:

> Sounds familiar - the NZ Army have recently bought a load of Pinzgauers,
> all of which started suffering from terminal problems and most of the
> fleet has been parked up since pending a factory modification. Still,
> it means there's about to be a load of Stage 1's for sale :)

Well, I think they're made in Britain now ;-)

--
Blast off and strike the evil Bydo empire!
 
On or around Thu, 30 Mar 2006 21:40:15 +0100, Alex
<[email protected]> enlightened us thusly:
>Good movie of the current generation Pinz on Stewart&Stevensons
>website (Uk importers/dealers/MOD suppliers)
>
>http://www.pinzgauer.uk.com/user_files/video/Pinzgauer.wmv
>

only works in IE. crap webdesign to the fore again.
--
Austin Shackles. www.ddol-las.net my opinions are just that
Travel The Galaxy! Meet Fascinating Life Forms...
------------------------------------------------\
>> http://www.schlockmercenary.com/ << \ ...and Kill them.
a webcartoon by Howard Tayler; I like it, maybe you will too!
 
You must log in or register to reply here.

Similar threads

the_wolf
Straightening a 110 rear tub
Replies
2
Views
459
the_wolf
the_wolf
S
Axles and Wheels - Which Type?
Replies
12
Views
883
Hicap phill
H
D
Stutter and stalling when under load P0336
Replies
4
Views
496
Defender or wife
D
S
Potential problems
Replies
1
Views
391
Keith_L
Keith_L
MrGorsky
And you thought Britpart were sh*t!
Replies
15
Views
945
Kev12
Kev12
Back
Top