Wednesday, Nov 04, 2009 at 08:12
Something I wrote a few years ago -->
GU3 WINCH MOUNT BRACKET
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This note describes a winch mounting bracket developed by myself in
conjunction with Brawn
winches for my 2002 GU4800 to fit within a standard
plastic bumper bar.
Is has application to most GU's but in particular to those with the
low radiator and chassis cross member that protects it.
This winch mounting system had to be low in weight and not interfere
with the air-bag system in the car ,as
well as fit within a standard
bumper with little modification.
A significant feature in making this practical was the decision to
use plasma rope which allowed the use of an aluminum hawse. This
takes up less room than the traditional roller fairlead hawse.
It allowed a standard size winch to be placed on a flat bar that sits
across the top of the chassis rails.
Pictures have been uploaded that show the winch bracket mounted
without the bumper and also the finished system in the car.
The main part of the bracket is a flat plate 700 X 150 X 6mm .
Holes for the 4 12mm chassis rail bolts are drilled 675mm apart at a
distance of 25 an 80mm from one edge "the front edge". The standard
winch bolt pattern of 4 holes in a 254X114mm rectangle were drilled
with front row of holes 18mm from the front edge of the plate.
I.E. front of winch mounts slightly forward of the front chassis rail
bolt holes.
The bracket (plate) as above was installed and tested and as expected
in showed significant twist under load.
Brawn (Colin Pond) had the idea to weld in vertical triangular plates
to brace it.
These were welded just near the winch mount holes and extended down
to the cross member that protects the deep radiator on the 4800 and
new 4.2 diesel Patrols.
The triangular bracing sections had small flanges welded to them and
8mm bolts were put through these and into holes drilled straight
through the radiator cross member beam.
These plates ran parallel to the length of the car and provide huge
resistance to twisting forces without impending air flow to the
radiator.
Indeed they had the incidental effect of significantly improving the
radiator protection.
On say 3 litre GUs this would not be possible and it would be
necessary to come up with an alternative, by using say thicker 8mm
plate initially and putting a fold in the back of the plate to create
an "angled section".
To complete the bracket a slotted flat piece of 6mm steel was welded
to the front edge of to hold the hawse.
Very little modification was required to the plastic bumper to
accommodate the new winch.
Just the two recessed vertical struts were removed with a
stanley
knife.
In fact the job was done with the number plate that heavily protrudes
into the bumper to remain in place. I found it hard to see the winch
rope take up though and later mounted the number plate a bit higher
and cut off the plastic number plate moulding.(as per photo's)
This project was done with use of specific
winches in mind which
allowed for reasonable access to the up/down winch clutch release.
I have the low end Brawn HR9000 winch - it would be harder to get at
the clutch in some other types but on their high end waterproof
winches Brawn can fit an "Air actuated solenoid" if clutch access was
a problem.
Apparently this winch mount system could be easily adapted to those
very common aftermarket "non winch" type bull bars with the vertical
metal stripes.
It took a lot of stuffing around to get this job done but it has come
up very
well.
In the end the bracket only weighed 8kg and the combined winch/bracket
with hawse, hook and 20meters of 8mm plasma rope only weighed 29.1kg
The cables and controller added another 4kg but this is mainly
mounted over the fuse box next to the battery.
I will do a separate post on actual winch once It has been properly
put thru its paces.
While only about 30kg was added in front of the front
wheels the cars
handling noticeably changed and it had a definite "floating feeling"
caused by the increased weight over the front
wheels. I did not like
this and exchanged the stock Nissan front shocks for some old Ironman
units from my previous GQ.
These have increased damping and made the car feel almost back to
normal.
Robin Miller
FollowupID:
657659