Whilst looking at the new FFRR, I noted that the maximum wading depth is given as 900mm (this was hinted at to me at LRE Eastnor earlier in the year although I assumed they meant some vehicle in the distant future).

Looking at the RRS, the current models have a wading depth, in off road mode, of 700mm. The pre-2010 models have a depth of 540mm.

Does anyone know why there was such a big change in the wading depth betwenn 2009 and 2010? Presumably either something electrical or something like a breather pipe was moved to a higher position. I think both models take air in to the engine from the same wing-mounted grille on the driver's side.

It's of interest to me because, whilst at Eastnor, the instructors stated that my RRS had the best wading depth of the group and stated 700mm. They obviously forgot that the older versions have the reduced depth limit and I didn't know enough to disagree. As we went through some quite deep water, I wonder if I actually exceeded the quoted depth.

I'm going to Eastnor again in October for another self-drive day and it would be good to have a better understanding of the whole thing in case we go wading again (which I'm sure we will). 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Yes - there are no wing intakes anymore on the new FFRR. The "vent" like trim on the doors is an ornament and of no practical use. Like the Evoque the intakes of the L405 are on top of the front wheel arches, under the edge of the clamshell bonnet, nicely protected from sucking in water or sand. This gives the Evoque the same wading depth as my Defender - 500mm and how the L405 can get 900mm with off road height in use - will be even more if you get the car into extended height!
Sorry I thought you were asking about the new FFRR, on second reading it appears you are talking about pre and post 2010MY RRS - it could be for the same reason in the RRS and the two above but I've not looked under the bonnet of a post 2010MY RRS to see where the intakes are 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Pre 2010 RRS have a wading depth of 700mm too. '08 RRS TDV8
I converted my diesel RRS to run on an environmentally friendly mixture of caribou fat and baby seals oil

Not according to the owner's manual they don't... 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

There seems to be a bit of confusion on the informations.

All the brochures say 700.
The off road manual says 700

The 2008-09 user manual says 540.

The previous manuals nothing that I can find.

Here another thread about it

http://rrsport.co.uk/forum/topic6385.html?highlight=wading

. '08 RRS TDV8
I converted my diesel RRS to run on an environmentally friendly mixture of caribou fat and baby seals oil

Yes, it's odd isn't it?

What is the "off road manual"? Not sure I've seen that...(think I'm about to look very silly asking that) 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

The handbook for my 07 2.7 has wading depth of 540mm. I do not understand why the later models would have a higher wading depth as the intakes systems are basically the same with the exception that the pipe that joins the intake to the airbox is waterproof on the later models.

Garry 07MY RRS TDV6
Arctic Frost
Aspen Interior

RRSTDV8 wrote:

Yes, it's odd isn't it?

What is the "off road manual"? Not sure I've seen that...(think I'm about to look very silly asking that)

Now this is wading

http://izismile.com/2009/07/15/the_underwater_car_36_pics.html Wanted a Series 2 LR since childhood but previously owned MY16 Disco Sport HSE TD4 Auto, MY13 RR Sport Black Edition TDV6 Auto, MY10 RR Sport HSE TDV6 Auto, 2007 Freelander 1 Freestyle TD4 Soft Top, 2009 Freelander 2 GS TD4 Auto, 2007 Freelander 2 GS TD4, 2004 Disco 2 Metropolis Auto, 2002 Disco 2 GS, 2000 Freelander 1 SE TD4 SW

Still hoping for a S2 one day!

muddywheels wrote:

Now this is wading

http://izismile.com/2009/07/15/the_underwater_car_36_pics.html

Back to the original question, looking at the LR3 (Disco 3) workshop manual, I think the wading depth is determined by the height of the breather pipes for the gearbox and the differentials.

I would guess that a quick "splash" isn't an issue but rather running the vehicle for a longish period in deep water is. I've seen suggestions that "hot axles can breathe in water through the breather pipe". Presumably, if the diff is hot and then submerged in cold water, it will cool and the atmosphere in it will contract and suck on the breather pipe.

I would assume that one could, if one knew the pipes' locations, extend them to give greater wading depth... 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Last edited by RRSTDV8 on Tue Oct 02 2012 9:23pm. Edited 1 time in total

RRSTDV8 wrote:

Presumably, if the diff is hot and then submerged in cold water, it will cool and the atmosphere in it will contract and suck on the breather pipe.

Quote:

I would assume that one could, if one knew where the pipes' locations, extend them to give greater wading depth...

What about the air intake ? Max wading depth (unless fitted with a snorkel) will be as high as the lowest air intake, breather or engine.

You could theoretically wade deeper than the air intake if you can maintain a bow wave and water depression by the air intake, but if you have to stop for any reason, best stop the engine immediately and not restart it  

"Roads ? Where we're going there are no roads." Back to the future.

The air intake is the wing vent and that is much higher than 700mm above the ground in off-road suspension mode. I would expect the air supply path to be air tight (and thus water tight to a reasonable degree). This leaves breathers and electrics as the controlling issue.

On the D3, the front diff breather appears to come up by the coolant header tank - I shall have a look in my RRS engine bay tomorrow (weather permitting) to see if it's the same. I guess, therefore, that the rear diff is the issue - the gearbox breather could easily be brought up in the engine bay too.

I will keep trying to find out - if only for my own interest. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

RRSTDV8 wrote:

The air intake is the wing vent and that is much higher than 700mm above the ground in off-road suspension mode. I would expect the air supply path to be air tight (and thus water tight to a reasonable degree).

Another thing to bear in mind is flotation I read yesterday the new FFRR has been deeper than 900mm but started to float off. Might sound silly, but in flowing currents (not raging), a slight amount of flotation can be the difference between setting the course and riding it. I'd be surprised if the RRS floated that easily though, but just one thing to bear in mind when thinking through the reasons for the wading limit being set where it is. 

"Roads ? Where we're going there are no roads." Back to the future.

True enough but the thing that set me off on this question was what had changed between years in the RRS that meant an increase of 160mm in the published wading depth - floating risk isn't it I'm sure.

Looking at the RRS in off road height, most of the body is still out of the water at 700mm so flotation shouldn't be too much of an issue. I've seen film of RRS with water coming over the bonnet - they looked like they were getting ready to float at that depth. Bear in mind that you need to displace 2.5m^3 of water to float one of these things...

The 900mm wading depth of the new FF is pretty spectacular. I'm looking forward to seeing one do that

I hear that Gaydon are extending their LRE track and adding more wading ditches - presumably there'll be a FF trench and an "everything else" trench . I'm at Eastnor on Saturday - if I remember, I'll ask what they added to test the new FF. Apparently they found the existing stuff too easy for it... 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed