Poor in puddles.

[smiffysmc]

Had to drive through some heavy rain on way home today.

I thought with the weight of the LC it'd romp through them. But it was the opposite. Shallow surface water had the truck twitching about. I was doing 40 mph. Running 285 75 16's Grabber AT2's,2" sus lift and up rated steering damper. So thought they'd cut through the water. I could understand if I was running 12.5 wide tyres on 10" wide rims.

Anyone else encountered this?

Cheers.

 

[fast but dim]

yep

I've aquaplaned twice on my at2's, both times in very heavy rain with standing water at 70 plus on the motorway. Very scary, and definately something i now am wary of when i approach standing water. If you lift off the throttle the slight weight shift to the front pushes the front wheels onto the tarmac.

 

[Chris]

Lock the centre diff
makes a massive difference in standing water
People will say 'oooh don't do that Oooh you'll get wind up boo hoo hoo'

Rubbish. Try it. Don't leave it in for roundabouts though

C

 

[smiffysmc]

Cheers.
Yip. I was thinking of putting on the centre diff but wasn't sure if you could do it on the move? My 1st Toyota Surf only had 4H with locked centre diff and used that in the wet to help the 33's, but never made that much difference.
I also thought about tyre pressure. I'm running high 30's just now. Not that I mean I'm floating, ha. Just footprint.

 

[smiffysmc]

yep

I've aquaplaned twice on my at2's, both times in very heavy rain with standing water at 70 plus on the motorway. Very scary, and definately something i now am wary of when i approach standing water. If you lift off the throttle the slight weight shift to the front pushes the front wheels onto the tarmac.

Ooooofffff, wouldn't fancy it at 70. Spare under crackers required.

 

[Jon Wildsmith]

the Toyo HT's I'm running on my 80 were very good through the standing water in the outside lane yesterday but they have two deep channels that look like they're designed for dispersing standing water.

 

[Towpack]

Sounds like more of a tyre problem to me. A good road only tyre will probably be far more efficient at clearing standing water from the road surface than an AT pattern which is, after all, a compromise. My LC had road tyres on when I bought it and the poorer wet weather performance was the first thing I noticed when I replaced them with AT's.

 

[clivehorridge]

I have exactly the same problem, but I've put it down to (i) and (ii) below:

(i) 305/70/16 tyres (too wide. They look good and give a wonderful ride on asphalt/gravel tracks but don't cut it in the mud. Should be tall & skinny!) Smiffysmc running 285's are maybe too wide as well? ;

(ii) 10" wide steel rims (offset measures 10cm from centre flange to inner rim edge) which pushes out the outer rim by 15cm. (similar I would imagine to running with spacers) is smiffysmc using spacers?;

(iii) GG AT2's great tyre, another similarity with smiffysmc. I have no complaints with them, great tyre except the sidewalls are very vulnerable to sharp rocks, but that's another matter.

I didn't have the problem with 235/70/16's, but they drifted on hot asphalt windy roads terribly which is why I went wide. (hot summer's here guy's.. sorry! )

Otherwise there's a 75mm OME sus lift and castor bushes and a fairly new uprated steering damper which I don't think have much effect on puddle snatch. It can be a bit scary though at speed trying to stay in a straight line when there's a lot of water collecting in the nearside.

 

[Graham]

Lock the centre diff
makes a massive difference in standing water
People will say 'oooh don't do that Oooh you'll get wind up boo hoo hoo'

Rubbish. Try it. Don't leave it in for roundabouts though

C

.
Spot on advice from Chris.
When I was in Norway for 2 winters, the slush and standing water is some thing to see.
But BFG, A/T. which really the AT2 A/T is a close copy of.

Even though the 120 is lighter than the 80, by about 350 kg, and I was running 265 x 70 x R17, through the rain puddles, the 120 was absolutely rock steady with center diff locked.
Even hitting standing water up around 100 mph.

When hitting slush, I would do no more than 70, and center diff locked.
It is quite strange just how by locking the center diff, tightens every thing up.
Nice actually.

It was quite easy to drive in the unused lane of the highway, and feel (rightly or wrongly) that the 120 was firm, and not about to throw a fit.

I would have thought, given the extra weight of 2600kg (guessing) to the 120 weight of 2250 would have kept it pretty solid in the standing water.

Gra.

 

[Andrew Prince]

Approached fast enough, any vehicle/tyre combo will aquaplane.
I am not surprised that the GFG AT/ GG AT2 tyres perform poorly in standing water - just look at the pattern and compare with fancy road tyres. You'll see that the road tyres have grooves to divert water off to the side (look at a Goodyear Eagle F1 tyre as a prime example). The BFG pattern has nothing like that - water won't really be pushed anywhere with the "crazy" tread pattern and water will quickly build up between the tread and the road surface = aquaplaning.

I have found my 80 incredibly steady in standing water with MTs on - I guess the big lugs push the water to the sides very easily. I have never aquaplaned once (touch wood) and have driven into a few decent puddles.

 

[smiffysmc]

Not using spacers. Think the rims are 8" wide, will need to check.
I had the khumo KL71's on my Surf. They did cope better and are directional tyres so have a V shaped pattern.
Hopefully the GG's will come into their own in the snow. I drive a gritter/plough so need to get to the yard in the morning.

So like like it'll be centre difflock in the puddles for me.

Can I put the centre diff on/off whilst moving?

Cheers.

 

[clivehorridge]

Just to clarify, I don't think Smiffysmc's problem is aquaplaning (and mine for sure isn't). It's a grab at the wheel pulling you over to one side like hitting the brake pedal with only one caliper working.
When you're in the puddle you instinctively steer against it to stay straight and when you exit, of course there's over-compensation so you swerve back on line.
It can be quite alarming if the water is 50mm or so deep and more so if its local to the gutter/road edge affecting only one wheel.
If the water is uniform accross the road, all you get is a balanced "braking" like hitting a ford too fast.
As a boy I had a Mk II Cortina with 1" spacers and it was hell to keep straight when one wheel hit standing water. I know that when I took the spacers off it was much less affected, if at all.
Smiffysmc isn't using spacers and 285's are not so wide as my silly 305's.
What rims are you running on? Do they have a big offset?

Anyway, thanks Gra for the centrelock advice. Just a push of the button on the dash sounds quite a civilized approach to the problem. I'll try it next time it rains, which (seriously here) is forecast for late October. (it was 42C today... again)

 

[Chris]

Centre diff? Damn wish I'd thought of that.

Chris

 

[Dave Docwra]

Chris, is that the pin 7 mod

 

[Chris]

What? Dave - there's a mod? What? Eh? Really? Wish I'd thought of that too. Hey, maybe I did

C

 

[smiffysmc]

Ha. I'm acting on your advice. Oh, and I've got that pin thing going on as well. Ha

But can I engage/disengage centre diff whilst on the move?

 

[Ecoman]

A few of my mates and I nicknamed the General Grabber AT2s "Ditch finders". They are a fantastic tyre both on and off road but give them standing water at any speed and they let go big time.

Hitting deep water at 40mph+ is risking aquaplaning anyway but as was already mentioned just y lifting the throttle a touch will shift the weight to the front wheels and depending on circumstances, may allow the tyres to recontact the road surface.

 

[Ecoman]

Yes you can engage centre diff on the move although you will have to back off the throttle to allow it to engage.

After I fitted the CDL switch I didn't do the pin 7 mod as I preferred the smooth change. By doing the pin mod it holds the truck in gear for a lot longer and then changes quite harshly.

 

[Chris]

Buy a CDL switch from Karl, stick it in the dash and you can lock the CD whilst driving. Forget the pin 7 mod completely unless you are an American. Have a search in the modifications section for 80s and you'll find there is a connection that is best unplugged underneath too, but for locking the middle diff whilst on the move in high range all you need is the switch for the dash. The plug part only relates to low range. You will find that locking it on the move also knocks your ABS off too. I wouldn't worry about that.

Chris

 

[Ecoman]

Smiffy already has the CDL switch. I fitted it after talking to you Chris