Gu recover points

[BillsGU]

Hmm. TD. Mine is a 2000 GU and as I said, Iron Man sell a kit that does not require removal of the Bull bar.

[mudski]

Hmm. TD. Mine is a 2000 GU and as I said, Iron Man sell a kit that does not require removal of the Buller.

Have you got a link to the kit? Or a pic. Yours will be the same as mine... Well, should be.
http://www.nissanpatrol.com.au/forum...ecovery-plates

[threedogs]

maybe there is an inspection hole further
down the chassis either way it will just be a copy

[BillsGU]

The kit is not on Iron Man's site - I was speaking to the owner about the issue I have and he said "Hang on, we have a kit that will do the job". As I posted before, there are access holes to the rear of where the plate bolts to the chassis and the kit comes with nuts complete with rods welded to them that feed into the holes and allow the bolts to be fastened.

A copy of what? It's just a plate with a hole in it to allow a shackle to be attached.

[Big Gags]

I have some notes from way back and thought that some of the calculation factors used might be of interest/use to some of you guys....

Rolling Resistance (RR) = Vehicle Weight / Ground Factor.

Ground Factors:

Smooth hard road = 25
Long Grass that fouls the front and underside of vehicle = 7
Hard wet sand, gravel, Soft wet sand = 6 or 5 (it states that experience to judge the degree of sinkage is required)
Loose dry sand, Shingle Beach, Gibber Desert = 4 or 3
Soft clay and black mud = 2 (a mud-like plasticine would start at 2 and decrease with sinkage to 1 where wheels and axles are completely submerged)

Example: for a 2 tonne vehicle being recovered from sand RR = 2/4 = 1/2 = 0.5 tonne

Next factor is Gradient Resistance (GR) = (Vehicle Weight / 60) x Angle of Slope (degrees)

Example: for a 2 tonne vehicle being recovered up a 20 degree slope GR = 2/60 x 20 = 2/3 = 0.66 tonne

Final factor is Damage Resistance (DR). For a wheeled vehicle under 5 tonne you add 0.25 per tonne for each locked wheel.

The final calculation of Pull Required (PR) is PR = RR + GR + DR

For the example of a 2 tonne vehicle bogged in sand on a 20 degree slope and with no damage to wheels the pull required would be:

PR = RR + GR + DR = 0.5 + 0.66 + 0 = 1.16 tonnes.

There is then a Safety Factor (SF) applied to compensate for any errors and to make allowance for any unforseen resistance. The SF applied is a quarter of the PR figured.

So for the example, the Total Pull Required (TPR) is 1.16 x 1.25 = 1.45 tonne.

I cannot confirm how the different calculation figures were developed but I can confirm that the army recovery mechanics who are the guys who recover vehicles for a living use these calculations when planning their recovery activities. Recce Mechs as they are known will also utilise snatch blocks to achieve the required levels of pull with Simple, Compound, Direct, and Indirect tackle layouts. The simplest layout for self-recovery that provides a mechanical advantage is to attach a snatch block to your anchor point and then loop your winch rope around the snatch block and attach it back to the vehicle. This effectively doubles the capacity of your winch (less some friction losses) and so if you have a 9,500 lb winch you are now pulling at 19,000 lb which is about 8.5 tonne and should be enough to get you out of pretty much anything!!!

[MudRunnerTD]

If I may stick my nose in here ,whatever you use for the rating or SWL etc as you both have pointed out and done a great job of explaining but to the layman am I right or wrong in assuming there is no way of knowing what weight your playing with if the vehicle is bogged to the floor ?
Seems to me that in my example it would be almost impossible to determine the weight and therefore the Breaking strain required , which maybe why so many recoverys end in tragedy or near miss .
For me if I can't winch I dig and I'm an expert plus at getting bogged .

I have some scenarios in this thread that you can use to get your head around how bad your recovery might be based on the depth of the crap your stuck in. Well worth a look

http://www.nissanpatrol.com.au/forum...e-Fundamentals

[BillsGU]

Yep Big Gags - they are the formulas I remember using years ago.

[threedogs]

Personally Id prefer a plate with nuts welded on , rather than just washers and nuts
Ive seen some pretty shoddy GQ and GU chassis over the years, hate to pull one
out of the chassis.
Just something to think about

[MB]

Pretty sure TD that’s what we welded up for AB’s GQ ARB bullbar years back mate. 5ish,mm plate with nuts tacked on three sides and galvanised - aligned with OEM chassis holes?


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[BillsGU]

Personally Id prefer a plate with nuts welded on , rather than just washers and nuts
Ive seen some pretty shoddy GQ and GU chassis over the years, hate to pull one
out of the chassis.
Just something to think about

A plate won't fit into the inspection hole. The only way to use a plate (on an early GU) would be to increase the size of the inspection hole or cut/bend the front of the chassis rail, either of which I would prefer not to do.

The majority of the forces on the recovery point would be shear and mostly taken up by the sides of the bolts. Correct bolt type is critical. If your chassis is that shoddy that the bolts may pull out I would think you have serious problems to worry about.