Defender bonnet tyre mount

[pop058]

Anyone know what thread and pitch the hold bolts on the bonnet for the spare wheel are ?. Contemplating putting my spare back there and need to run a clearing tap down them The threads are a little weather beaten to say the least.

TIA

174482

[JDNSW]

As far as I am aware, bonnet mount for Defenders has never been sold (or at least) approved in Australia. This being the case the mount you has most likely been designed for or copied from a Series mount, and as such is most likely 9/16" BSF.

[pop058]

As far as I am aware, bonnet mount for Defenders has never been sold (or at least) approved in Australia. This being the case the mount you has most likely been designed for or copied from a Series mount, and as such is most likely 9/16" BSF.

My 92 has the ( pictured) mounts from factory. Inc's 130 also has them. I tried a 12mm as well as a 1/2" UNF and they both ( just) start but I would prefer to run the correct tap down them first.
I tried the one from my 2A and it is way to big.

[1950landy]

Thought you would have had a thread gauge Paul.

[windsock]

My 84 110 has a similar mount but the lock pin goes through a wheel nut hole not through the centre.

By memory I replaced the bolts a few years back from my metric collection if that helps. Cannot find my thread gauge due to a shed rearrangement that is incomplete. [bighmmm]

[towe0609]

M12 x 1.75

[Don 130]

My '97 130 has a bonnet mount and was delivered new to NSW NPWS before I got hold of it.
Don.

[JDNSW]

Looks like I am learning!

[rovers4]

Another 97 Def 110 with bonnet mount.

[pop058]

M12 x 1.75

Yep, tankuverimuch [thumbsupbig]

174521

[pop058]

Thanks to all [thumbsupbig]

[RANDLOVER]

Looks like I am learning!

Looks like one can get away with a bonnet mount spare wheel on a Defender, but I doubt one can attach the "pioneer tools" of shovel and pick-axe, like the Series ones had?

[V8Ian]

Looks like I am learning!
Proving that intelligent people never stop(learning).

[W&KO]

Another 97 Def 110 with bonnet mount.

Im guessing your 110 is a ute?

[JDNSW]

Proving that intelligent people never stop(learning).

Isn't that one of everyone's major goals?

[incisor]

Thanks to all [thumbsupbig]


i found it makes the truck just that little more economical to run btw..

[windsock]

Thanks to all [thumbsupbig]

Pictures of the rest of the 110? [biggrin]

[windsock]

i found it makes the truck just that little more economical to run btw..

There is a post on here with an attached report I remember reading and searched for it just now - by rrturbo back in 2012.

Wheel on Bonnet = Aerodynamic improvement (https://www.aulro.com/afvb/technical-chatter/155266-wheel-bonnet-aerodynamic-improvement-post1724624.html#post1724624)

I know it changes a lot about the aerodynamics as the window washer water pattern with and without the bonnet mounted tyre is so vastly different.

[pop058]

Pictures of the rest of the 110? [biggrin]

174548 174549

[pop058]

i found it makes the truck just that little more economical to run btw..

Directing the wind past the ( round) tyre as opposed to hitting the block of flats head on ?? [biggrin]

[JDNSW]

Probably works as a vortex generator and allows the air coming over the top of the bonnet to break away and go over the roof and off to the sides rather than going full tilt against the windscreen.

[pop058]

Directing the wind past the ( round) tyre as opposed to hitting the block of flats head on ?? [biggrin]


Probably works as a vortex generator and allows the air coming over the top of the bonnet to break away and go over the roof and off to the sides rather than going full tilt against the windscreen.

[thumbsupbig]

[67hardtop]

Does anyone have a pic of the plate that goes on the top of the spare wheel mount? My stage 1 has this same mount but has no top plate. I have the bolts but that's all. Cheers

[rovers4]

Im guessing your 110 is a ute?

Nup. 110 Wagon, with a Dolphin logo on each side, just in front of the front doors.
Spare is currently on rear door. Only use bonnet mount for 2nd if going remote.

[pop058]

Does anyone have a pic of the plate that goes on the top of the spare wheel mount? My stage 1 has this same mount but has no top plate. I have the bolts but that's all. Cheers

I made the one I have. Just a piece of thick alloy U channel with locators and holes.

[incisor]

174552



174553


is whats on mine

available on ebay etc

[W&KO]

Nup. 110 Wagon, with a Dolphin logo on each side, just in front of the front doors.
Spare is currently on rear door. Only use bonnet mount for 2nd if going remote.

Are, so not factory…..

[windsock]

Probably works as a vortex generator and allows the air coming over the top of the bonnet to break away and go over the roof and off to the sides rather than going full tilt against the windscreen.

Yes, I think you are right.

Without the tyre mounted the wind screen washer water goes up and out to the sides in a smooth pattern and hence in the full sweep of the wiper blades.

With the tyre mounted, the water is pulled towards the centre and slightly downwards with an oscillating/turbulent pattern of movement on the wind screen on both water jets and hence slightly towards the outside sweep area of the wiper blades.

235/85 16 Bridgestone muddies tyre. When I ran the old 7.50/16 Dunlops they were a skinnier tyre and thus slightly flatter on the bonnet, the pattern if I recall was slight taller up the window but still pulled towards the centre.

[67hardtop]

174552



174553


is whats on mine

available on ebay etcOrdered today and paid for. Don't like buying of this particular seller but needs must.

[Tombie]

Yes, I think you are right.

Without the tyre mounted the wind screen washer water goes up and out to the sides in a smooth pattern and hence in the full sweep of the wiper blades.

With the tyre mounted, the water is pulled towards the centre and slightly downwards with an oscillating/turbulent pattern of movement on the wind screen on both water jets and hence slightly towards the outside sweep area of the wiper blades.

235/85 16 Bridgestone muddies tyre. When I ran the old 7.50/16 Dunlops they were a skinnier tyre and thus slightly flatter on the bonnet, the pattern if I recall was slight taller up the window but still pulled towards the centre.

A study tested it in a wind tunnel, the result was an improved cd with tyre on bonnet.

Study link here:

Wheel on Bonnet = Aerodynamic improvement (https://www.aulro.com/afvb/technical-chatter/155266-wheel-bonnet-aerodynamic-improvement-post1724624.html#post1724624)

[windsock]

A study tested it in a wind tunnel, the result was an improved cd with tyre on bonnet.

Study link here:

Wheel on Bonnet = Aerodynamic improvement (https://www.aulro.com/afvb/technical-chatter/155266-wheel-bonnet-aerodynamic-improvement-post1724624.html#post1724624)

Yep, post 18 (https://www.aulro.com/afvb/general-chat/288290-defender-bonnet-tyre-mount-post3115357.html#post3115357) here... [thumbsupbig]

I recalled reading that back in 2012 or so when he posted the link and anecdotally over the years have seen slight differences in fuel use over a long trip and it can mean the difference between 4th or 5th gear on shorter trips around here in our winds (Exhaust gas temps of 550 or 650 - tailwinds = EGT of 400 or less). Where I live, we are known for our winds and with the tyre bonnet-mounted, it can break up a bit of the head wind. Out where I spend a lot of time we average 6m/s along the ridgeline and 5m/s on the flats. A long stretch of road some 15-20km is slightly up hill all the way (40masl to 120masl over 15km) and into the prevailing wind direction.

The remaining 10km is crosswind or tailwind and the HCPU helps catch that... [bigwhistle]