17" on 3.0 D4 legal in NSW due to placard

[Graeme]

I've just had a detailed conversation with a NSW RTA Technical Services person who stated categorically that I can legally fit the appropriate/smaller brakes to my 3.0 D4 because LR have listed the 17" rim size on the tyre placard as an optional size. Also stated was that no Engineer's Certificate is required. All that has to be done is to fit the LR brake components applicable to the rim size. It was stated that even though LR might not have supplied the Australian nor any market with a vehicle so fitted, it does not alter the legality of converting the vehicle to accept those wheels. If the 17" was not listed as an optional size then an Engineers Certificate would have been required, not just a blanket dis-allowance of such a conversion, although if 18" was listed (which it is) then once again no Engineer's Certificate would be required.

I'm not about to change brake discs and calipers yet, but its good to have confirmed that is a legal option. The fitment of 2009 V8 brakes might require an Engineer's Certificate as that size is not fitted to any 2010 model but perhaps as both models are designated L319, the certificate might not be required.

Note to self: Do not allow that tyre placard to be removed!

[101RRS]

And of course you have that in writing:). They are notorious for giving incorrect information.

Garry

[DiscoSaffa]

I would also hate to test that in an insurance claim...... :eek:

[Graeme]

If I was to get serious about going down that path, I'd get written confirmation from the RTA. I'd also consult my insurer to find out what they thought about it.

I'm still hoping for 18" rims.

[rmp]

If you fit smaller brakes to a D4 then I suspect you also need to recalibrate the computers.

When the computer decides a little braking is in order it will activate the brakes on a given wheel with a certain amount of brake pressure for a certain amount of time. Being a 3.0, it will assume the 3.0 brakes are fitted. If the smaller brakes are fitted then it'll send the same brake signal but the actual braking effect will be less as the brakes are less effective. This is not dissimilar to the effect of fitting much larger and heavier tyres.

Thus, this brake mod will throw out the CBC, ABS, ESC, EBA, EBD, ETC and TSC, all of which rely on computer-controlled brakes.

Now the logic above may be wrong and the 2.7 brakes react precisely the same as the 3.0 -- but then why are they different sizes. Only LR engineers could tell us, not the RTA. So I suspect there is a difference. The next question is the magnitude of the change, which is unknown to me, and I'd be quite suprised if it were known to the RTA, therefore I am surprised they are prepared to state so categorically this mod is ok.

Perhaps you could put this to the RTA person. I will be very interested to hear his response.

Maybe also mention that manufacturers are typically lazy and use just the one placard for all vehicle models irrespective of the rim or tyre sizes that will fit. As we know, 17s physically do not fit on the 3.0. With sophsicated vehicles like the D4 the days of just slapping on different bits and pieces then calling it good are over.

As Land Rover did not intend 17s to be fitted to the D4 any fitting of smaller brakes is likely to cause warranty issues.

The smaller brakes will not be unable to stop the vehicle by any means. There are specific braking tests which need to be done in a variety of configurations and if the brakes can stop a 2.7 to that effect they can certainly stop a 3.0 as they are the same GVM or close enough.

You'd definitely need to notify your insurer.

[Blknight.aus]

ohhh not quite...... (well at least under QLD regs)


if your vehicle was provided with rotors and calipers of size X then you cant go down to size W so you can fit the smaller rims without a re-engineer... you can go up to size y without it becuase you havent decreased the overall available braking ability.

if it came from factory with the 17 inch brake set then your laughing.

personally Im of the opinion that ANY brake mods should require at least a certified technical review

[ADMIRAL]

yes....perhaps a less involved option to pursue the special 18" wheels gghaggis was investigating.

[Sprint]

dumb question

why the **** would ANYONE ever even consider REDUCING the BRAKING ability of thier vehicle?

ffs, if you dont want to wreck your 18"s by going off road, get something that doesnt need big wheels with licorice strip tyres

[stig0000]

dumb question

why the **** would ANYONE ever even consider REDUCING the BRAKING ability of thier vehicle?

ffs, if you dont want to wreck your 18"s by going off road, get something that doesnt need big wheels with licorice strip tyres

ageed;);) tho with a few buts???;)

[Graeme]

I expect the computer-assisted braking uses calculated deceleration from rate of speed reduction as it does for preventing air suspension height adjustments when deceleration rate exceeds a particular threshold, combined with wheel slip monitoring rather than pre-determined periods of ABS pump operation which could not take into account differences in adhesion due to road surface, tyre compound or load differences. LR has documented D4 emergency braking as applying brakes up to the limit of adhesion.

LR do supply the D4 with 17" rims in the UK but regardless, 18" rims use the same brake package. Even if 17" weren't listed, 18" require the smaller brake package which then allows fitment of 17".

If 18" rims can be found to fit the larger brakes then that's what I'd use, but if the smaller brakes were to be fitted then may as well use 17" rims. I'm not going to stick with 19" for too long as they impose too many compromises for my use.

[Graeme]

Interesting to note that LR have fitted the rear callipers for the 2.7 to a 3.0 D4 to overcome the squealing whilst reversing problem, using the D4's discs and calliper mounting brackets. Now 17" rims will fit on the rear of any vehicle so fitted. The discs are the same size.

[scarry]

LR do supply the D4 with 17" rims in the UK


Is that the 3.0L D4?

The D4 is a fantastic vehicle,but with 19" rims won't do the job i need it to do.

[gghaggis]

The 17" rims are only fitted to the 2.7 ltr TDV6 - they don't fit the 3.0 ltr with the larger front brake callipers.

However, I've been quite surprised by the offroad performance of the 3.0 ltr on decent 19" AT's, and I expect it to be even better once the GG AT2's are released in that size.

Ideally however, you'd want to try and fit 18" rims and use either the 265/65/R18 or 275/65/18 sized AT's.

I need another 8 or 9 people to commit to a set of 18" rims before I can get the alloy 18" rims made up to fit the D4 (minimum of 15 sets required for a custom order).

So instead of moaning about it ................ :BigThumb:

Cheers,

Gordon

[Graeme]

I need another 8 or 9 people to commit to a set of 18" rims before I can get the alloy 18" rims made up to fit the D4 (minimum of 15 sets required for a custom order).
I am surprised at the lack of support for this option, possibly due to new owners not having driven in areas where rocks destroy sidewalls.

[CaverD3]

I would think fitting the D3 V8 discs and calipers would give the same brake performance. And if you put brembos on.........[bigwhistle]

[Graeme]

I've wondered if the D3 V8 front callipers would fit over the 3.0 discs being only 5mm greater radius spec-wise. However 2.7 callipers would be a lot easier to find s/h.

[Graeme]

Yesterday I had the opportunity to chat with an assessor for my insurer, explaining all aspects of such a modification, including a proposed tyre size. After saying that he wouldn't notice such a change, his only requirment was that the vehicle must be roadworthy as far as the RTA is concerned, but that I should consider having the modification noted on the policy.

Today I spoke with the insurer regarding adding a notation to the policy if such a modification was made and was advised that they no longer make notations on policies unless an accessory is required to be insured (bull-bars?) or if additional alarm or security devices are fitted. Any modification is allowed as long as the modification does not make the vehicle unroadworthy.

Therefore I see the door quite open to fit 17" rims, in NSW at least. I wont rush into a conversion, but there is a good chance that it will happen before the end of this year in the absence of a suitable alternate solution. I will shortly ascertain if my 17" rims fit over the existing rear caliper bracket, as I understand that the 2.7 rear calipers fit the existing bracket but the bracket looks too bulky.

[Disco4SE]

Hi gghaggis, I am definately interested in the 18" rims. I would like to see a photo of them first. Did you sus out a design?

[Graeme]

Disco4SE,
Would you be fitting LT tyres and if so, what & what size?

[Disco4SE]

Hi Graeme, probably 265/65/18's in an AT. Not really interested in muds at the moment, however it would be good to know that there is a choice if I wanted to fit them.
I have ordered the Pirelli Scorpians for the moment. Not sure when they are arriving because of demand. Its a bummer with the 19's. I really do like the SE rims.

[Graeme]

I've only found the BFG AT in that size but wonder if you have uncovered others. I'm not particularly impressed with the BFG case in the tread area, as well as being larger in diameter and wider than I'd like. I hear another story of buldges (pending blow-outs, or actual blow-outs at 110 kph in the case of my daughter with another on its way) every so often directly from owners who are real fans of the BG AT and even though the tyre history is unknown to me, the fact that it happens makes me want to not use them.

[Disco4SE]

Graeme, I too had a bad experience with BFG's. I have always used Cooper Discovery ATR's on my Landcruisers. They are excellent in the wet, good in the mud (for an ATR) and outlast most tyres.

[Graeme]

The Cooper ATR is 275/65-18 though.

[Disco4SE]

Yeah I know Graeme. These obviously wont fit the Disco, unfortunately

[Graeme]

I know of a D3 that has Cooper ST in that size, although its owner has commented that they're too big. It looks really mean though.

[Graeme]

The lack of 18" LT tyres excepting for 275/65-18 is my reason for seriously contemplating 17". There's no sense in getting special order 18" rims if appropriate tyres are not available. Its not the extra sidewall itself, but the LT construction that I'm wanting. The 255/55-19 aquaplane more than enough (again today several times) so going wider is not my preference. LT245/70-17 is what I'd like to run as a best compromise.

[Slunnie]

Hi Graeme, you may find that the more open pattern tyres don't aquaplane as much as a more closed pattern if you're worried about the width. As you know I'm running 285 on the D2 and so far it has been fine, but that said Johns 275's on the D3 look like they have a much wider treadface.

[chuck]

Graeme

I have not found the MTR's to aquaplane at all.
In fact their grip in the wet surprises me.

Following your other thread would it not be better to trial the 17's rather than change shocks.

BTW I drove a 200 series on Friday & the ride is definitely not as good as a D3especially as mine has 19" MTR's & the 200 series had OEM 17's. I have to admit the power was pretty good though.

Regards

Chuck

[Graeme]

I have no doubt that a more open pattern wont aquaplane as much and have considered using MTRs in 275/65-18 if 18" rims were to become available, retaining the 19" for general use. MTRs appear to not be as wide as some other brands and therefore may not rub as much. However its not just the rubbing, its the width causing higher fuel consumption and giving a generally bouncier ride.

The aquaplaning of the current tyres would be lessened if run at higher pressures than what I use for the gravel and rough roads that I traverse regularly.

I suspect the ride difference between 19" passenger tyres and 17" LT tyres is going to be minimal and insignificant compared with the effect of stiff shocks compared with softer shocks. I ran my LT D2 tyres at lowish pressures for a softer ride and would do the same with 17".

Edit: The 275/65-18 MTR are only LI 113 & max 50psi so might not have a harsh ride yet tough sidewalls. Duratracs have a more general-purpose tread but not the Kevlar sidewalls.

[Graeme]

Following your other thread would it not be better to trial the 17's rather than change shocks.
In Overlander's 2.7 D4/Prado comparison its noted that the 2.7's ride in 18" is better than that of the 3.0 on 19" & 20".

I'd like to fit the 17" if they are to be fitted before resorting to changing shocks but want to be sure there are no suitable alternatives before removing the larger front discs and don't think the shocks can wait that long.

[geckovet]

Coopers are apparently now doing an ATR 265 60/R18.
Slightly wider but very similar size to the factory size18

[Graeme]

265/60-18 is not a LT tyre in any other brand so may also only be a passenger tyre. Its nominal sidewall height is less than any other LT I've uncovered. My reservations about Cooper tyres in general and my dislike of the ATR's road manners on my D2 in 235/70-16 means they wouldn't be on my list anyway.

[Graeme]

I spoke with an RTA engineering signatory who said straight away that he will happily approve the brake change. The RTA will require a brake test so I need to arrange one after fitment. The engineer wants to be
contacted again once the conversion is done and I have the brake test results, so all systems go -yeah!

I'll be using all new genuine LR parts.

[CaverD3]

Is that just the standard pink slip brake test or more involved?

[Graeme]

I don't know - I'll ask the RTA. I need to find out from the RTA about the GVM question and whether there are any special surface requirements, eg a wet road won't show-up very well.

Edit: No, its a special test by an engineering signatory.

[Graeme]

The dastardly deed is in progress - the big front brakes are gone and 17" rims fitted. I'm planning to do the rears tonight and finish with a proper bleed tomorrow. A rego brake test will be done ASAP as proof that the brakes work sufficiently well before getting back to the engineer for certification.

[oldsalt]

I'll await your report with great interest Graeme - it certainly opens up some interesting possibilities for those of us considering a D4-3.0 but were put off by the inabiltiy to fit 17" rims and tyres....(my preferred size for serious off-road work)
cheers.

[Disco4SE]

The warranty issue would be a major concern for me after spending $90k odd.
I'll be sticking with the bigger factory brakes and maybe looking at the 18" wheels through Gordon at a later date.
Cheers, Craig

[Graeme]

17" fitted all round now. The X5 17" rim almost cleared the rear 2.7 caliper fitted to the 3.0 bracket and rotors but even if they caliper was shaved there would be so little clearance that anything foreign would interfere with the caliper. The rear 3.0 caliper fitted to the 2.7 bracket does not nearly allow fitment of the X5 17" rim. The rear pads are interchangeable except that the 2.7 outside one has a sticky back to adhere to the caliper fingers. The rear 3.0 pads have a slightly larger contact area but the shape of the leading edge of the pad material does not disperse rubbish as well as the 2.7 shape. My 3.0 rear calipers are the early aluminium ones, not the later cast iron ones.

I don't know how much I imagined it, but the ride improvement on the short but bumpy drive from the shed to back to the house was quite significant, albeit comparing new tyres with lots of tread with quite worn 19". I thought going to an LT tyre might counteract any improvement due to extra sidewall but maybe not - I'll get a better idea over the next few days.

I'll refit the 19" for the brake test.

[tempestv8]

Hi Graeme,

From what I know of some BMW X5 alloy wheels, I know that the wheel nuts do not wind into the studs as far as the genuine Land Rover alloys would allow.

Which would mean that when using BMW X5 alloy wheels on the D4, the wheel studs would be more stressed, as they are holding the BMW wheel with less thread.

Maybe this has changed with the later X5 wheel designs, but the first gen X5 alloys were like that, even though the PCD was the same. By this reason alone, if still valid, I would stick with LR alloys.

Congrats on fitting the 2.7 calipers on your 3.0 vehicle. Do let us know how you are going with the tests, etc.

Do keep us up to date!

[Graeme]

The nuts are special ones (ie not the common acorn nuts) with a shank to go down into the hole. They engage with over 10 threads, more than the original and legally-required 9 threads, so all is well in that dept. I'm undecided yet as to which rims will be fitted for certification but can't think of any reason why not to have the X5 rims.

[buz01]

Hi Graeme,
do you want to sell the brake callipers you have removed?

[Graeme]

No, in case I want to refit them sometime.

[Blknight.aus]

the standard for the test is a dry flat road (I assume its ment to be bitumen)

[Graeme]

After bedding in the pads on the first sealed road, the brakes are more sensitive and require less pressure than the 45K worn originals. During the bedding-in, I had to remind myself to stop at maximum retardation rather than just very quickly because they were so effective. I thought the vehicle was about to do a forward roll - it was down-hill afterall! I didn't expect the new tyres would grip that well.