Tyre skidding issue

[dom14]

Hi guys,
I got some secondhand wheels and tyres for my RB30.
They are LT235/85R16.
By the looks of it, they are quite similar to ATs.
I previously had 225/75R16 ATs which were good, but smaller than standard tyres that were suppose to have
on a GQ. I still got them with the wheels.
I've attached photos of both of them.
My issue is that these 235/85R16 LTs skid pretty badly on wet road, when I brake or when I take sharp turns.
So much so, I should say it's fairly dangerous.
They act pretty much like big muddies.
I don't have any big muddies at the moment, but past experience tells me those big muddies skid lot easier on wet roads.
If you guys look at the pictures, there is plenty of tread.
225/75 R16 ATs have never skid like this. Even though they are too small, they got pretty good traction.
I got over three inches extra height by putting on these 235/85 LTs.
So, I'm "happy" with the height and non wet road driving.
In theory, bigger the tyre, more tyre surface touches the ground.
So, I was expecting even better traction with these 235/85 LTs.
But, they are not.
I have to be very conscious about my driving style when raining or wet road.

What's wrong with these 235/85 LTs, guys?
They are obviously not muddies, yet the traction is pretty bad.
They are wider and touches more ground than my old 225/75 ATs, and got more treads as well.
Yet, they got pretty bad traction.

First photo is the old 225/75 AT. Last three photos are the 235/85 LTs, which I have on the GQ right now.
If I keep driving with them, I feel like it's a matter of time before I crash into something, when I brake on wet road.

What's wrong with them?

Thanks for any advice.

[Clunk]

I woukd say theyve just about had it, compound has probably gone hard and there isnt a huge amount of tread left........ my old bfg ats did that

[Cuppa]

I reckon Clunk is right!

[nissannewby]

I reckon Clunk is right!

X3 but those tyres are absolutely shite in the wet even new. I had a set and hated them

[dom14]

X3 but those tyres are absolutely shite in the wet even new. I had a set and hated them

Yeah. The tyres got plenty of tread left. I don't it's the wear.
Either tyres are crxp or they are way too old and somehow lost the traction.
I was particularly interested in 235/85 because they give me the standard height( or slightly above that) with only 10mm extra width than my old
tiny 225/75 s. But, these 225/75 s are still good after many years of use. Traction is great too.

I have another 6 of these 235/85 s. Four of them has better tread depth than the above current four on the fourby.

You can see them at the bottom of the first picture.

I will post their pictures tomorrow and hoping to get some opinions from you guys.

In the meantime, I have to be careful with these four on the car, 'cos it's pouring pretty much every day now in Melbourne.

I can put the 225/75 s back, but when I look at Patrol, I would feel like looking at a midget with those tiny tyres. :)

[dom14]

I woukd say theyve just about had it, compound has probably gone hard and there isnt a huge amount of tread left........ my old bfg ats did that

Hmmm. I didn't pay a lot for them, so I reckon it's not a huge loss.

BTW mate, my old 225/75 Michelins are still good. It's that they are too small. After so many years of road(and sometime off road) use, their traction is still good and very little wear.
Too bad they are not 31 inch ones. 225/75 R16 comes to around 29 inch tyre height, as oppose to 31.5 standard tyre height.

I got six other 235/85 s with pretty good tread depth. I'm thinking about putting them onto the rims with those 235/85 s in the fourby and see how it goes.
I'll post pictures of them tomorrow and see what you guys think.

Changing tyres manually - even with the manual tyre changer is hell of a 'good' exercise. :icon_bonk:

[Rock Trol]

Have a look on the sidewall for a four digit number. That will tell you the age of the tire. The first two digits are the week and the last two are the year. The 235's should have better grip as they are wider and taller.
What pressure are you running? Maybe lower them a tad so that the tire has a bigger footprint.

[threedogs]

Why that size the majority dont use them , either get 265s which I think is OE
or go bigger and buy yourself some 285s. You can get these 2 sizes in a Milkbar lol

[Bigcol]

I would suggest that Clunky is right

there dont look like a lot of tread left on those ones in the pictures........ probably less than 40% by guessing
have a look at the tread bar in between the "blocks" of tread - measure that distance- less than 3mm and they are cactii

also look for the date stamp on them
as the tyres get older, the compound gets harder - tyres only have a good shelf life of 5 yrs after that they are burnout tyres

years ago in another lifetime, we used to buy tyres and store them for as long as possible - 2 maybe 3 years, then whack them on the V8 on a Friday night, they spin like crazy, but dont leave rubber........

save your coin and buy a new set of tyres, you will wonder why you didnt do it earlier
I know sometimes coin is hard to get - spent many a weekend buying 2nd hand tyres to last a few months then change them, but at the end of the day - driving with confidence in your cars ability is worth the extra

[dom14]

Why that size the majority dont use them , either get 265s which I think is OE
or go bigger and buy yourself some 285s. You can get these 2 sizes in a Milkbar lol

Yes, but how do we explain my little old 225/75 s have a better traction than these 235/85 s?!!

I've been using the 225/75 Michelins on highways for over five years(since 2009).
They are still pretty good, except the Patrol looks like a midget with them on. :wink:

I haven't had 265 s or 285 s 'cos I haven't been on any serious mud trekking lately.
So, I thought, narrower tyres are better for road and mileage.
Another thing is that the constant rumbling noise I used to get from wider tyres when on highways(especially muddies) used
to drive me nuts.
My fourby is a standard carby RB30 with no turbo or other power enhancing mods.
So, it's not great for serious mud off roading, until I EFI it and then turbo it.
EFI'ing is not too hard. Parts are easily come by. But, that's not the case with a turbo gear.
Brand new turbo gear is out of question for me.
So, I'm looking for secondhand ones from a VL Commodore.
Rather than collecting bit and pieces, I'm searching for the whole lot from a Commodore.

[dom14]

I would suggest that Clunky is right

there dont look like a lot of tread left on those ones in the pictures........ probably less than 40% by guessing
have a look at the tread bar in between the "blocks" of tread - measure that distance- less than 3mm and they are cactii

also look for the date stamp on them
as the tyres get older, the compound gets harder - tyres only have a good shelf life of 5 yrs after that they are burnout tyres

years ago in another lifetime, we used to buy tyres and store them for as long as possible - 2 maybe 3 years, then whack them on the V8 on a Friday night, they spin like crazy, but dont leave rubber........

save your coin and buy a new set of tyres, you will wonder why you didnt do it earlier
I know sometimes coin is hard to get - spent many a weekend buying 2nd hand tyres to last a few months then change them, but at the end of the day - driving with confidence in your cars ability is worth the extra


Thanks mate. Let me have a look again and I'll post some pictures.

[Clunk]

Yes, but how do we explain my little old 225/75 s have a better traction than these 235/85 s?!!

I've been using the 225/75 Michelins on highways for over five years(since 2009).
They are still pretty good, except the Patrol looks like a midget with them on. :wink:

I haven't had 265 s or 285 s 'cos I haven't been on any serious mud trekking lately.
So, I thought, narrower tyres are better for road and mileage.
Another thing is that the constant rumbling noise I used to get from wider tyres when on highways(especially muddies) used
to drive me nuts.
My fourby is a standard carby RB30 with no turbo or other power enhancing mods.
So, it's not great for serious mud off roading, until I EFI it and then turbo it.
EFI'ing is not too hard. Parts are easily come by. But, that's not the case with a turbo gear.
Brand new turbo gear is out of question for me.
So, I'm looking for secondhand ones from a VL Commodore.
Rather than collecting bit and pieces, I'm searching for the whole lot from a Commodore.
Maybe the Michelin tyre has a better softer compound that takes longer to go hard than the Maxxis.........

[Bigcol]

they have
the OLD Michelin were a great tyre - easy 100K + out of them

they changed the compound around 2010 to compete with constant sales.............

[dom14]

Have a look on the sidewall for a four digit number. That will tell you the age of the tire. The first two digits are the week and the last two are the year. The 235's should have better grip as they are wider and taller.
What pressure are you running? Maybe lower them a tad so that the tire has a bigger footprint.

I'm running them on 40 PSI atm. Sometime I drop the front ones to 35.
But, I keep back ones at 40, 'cos I keep a fair bit of gear and tools at the back.
Is that ok?
I'll try lowering the pressure and see how it goes.
Thanks mate.

[Bigcol]

I usually run 40 in the rear and 38 in the front for normal use

when towing my Van, I run 45 in the rear and 40 in the front

[nissannewby]

X3 but those tyres are absolutely shite in the wet even new. I had a set and hated them

I should alsl mention the set i had were 33x12.5 so much more of a footprint than yours. They are crap lol

[dom14]

I should alsl mention the set i had were 33x12.5 so much more of a footprint than yours. They are crap lol

I'm happy to accept them as a donation, in case you wanna give them away. :wink:

[dom14]

These are the close-up photos of the front tyre and the rear one. The last two photos are from the rear one.

If you guys can help me with locating the tyres age and whether the tread depth is acceptable, what would be great.

[dom14]

I usually run 40 in the rear and 38 in the front for normal use

when towing my Van, I run 45 in the rear and 40 in the front

Ok, cool. That means I haven't been pumping too much air into them.

[dom14]

These are the photos of the six tyres I have in the backyard. They appear to have plenty of tread left.
They are 235/85 s.
I'm not sure whether they are ATs or "technically" muddies.
I'm hoping you guys can shed some light on my ignorance?

I'm planning to put them on the existing 235/85 rims and see how they go.

I can't afford a new set of tyres atm. I'm about a grand short for that. :icon_bonk:

[threedogs]

I'd say they were made in 2011,
35 psi front and rear wont hurt anything

[dom14]

I'd say they were made in 2011,
35 psi front and rear wont hurt anything

That means they are not that old. Even years younger than my old 225/75s.

Tread depth on them aren't bad either(I think).

So, I reckon these 235/85s(ones I have on the Patrol atm) are shite, whether they are new or old??!!

They are made in Taiwan. But, isn't everthing is either made in Taiwan or China these days? :D

[Bigcol]

yeppers - the pic with the "0411" thats the date stamp

also, the tread bar I was talking about to measure the tread depth
58629

[dom14]

yeppers - the pic with the "0411" thats the date stamp

also, the tread bar I was talking about to measure the tread depth


Hi mate,
These are the pictures of the tread depth marks on the tyres.

If I'm correct following your advice, the tread marks are visible on all of them.
Except the front ones are obviously bit bashed up on hard gravel driving.
But, the rear ones look pretty good by the looks of it.

Am I right?

[Clunk]

My opinion only....... fronts are shot and youve got a couple of mm left (if that) on the rears...... I'd be replacing them

[Rock Trol]

My opinion only....... fronts are shot and youve got a couple of mm left (if that) on the rears...... I'd be replacing them

X2. They look worn and ready for replacement. It's probably better to run your 225's until you save that grand and then buy a new set. From what you have said the car sounds dangerous to drive. Sounds like my GU when it had the Dunlop road slippers on split rims. Scary in the wet.

[dom14]

Thanks guys. Yep, it looks like I got burnt when I bought the tyres.
At least now I know what to look for when or if I ever buy used tyres.
Thanks for the valuable advice.

What do you guys think of these other 235/85 s that I have in my backyard?
There are three pictures of them attached here.
I have six of them with fairly good tread depth by the looks of it(around 6mm or more)

[Clunk]

They look in better condition than the Maxxis, but I dont know what Coppers are like, so I guess proof will be in the pudding

[dom14]

They look in better condition than the Maxxis, but I dont know what Coppers are like, so I guess proof will be in the pudding

I reckon I'll try them on anyway. I got nothing to loose.
It's a matter of sweating a little bit and changing them onto those rims in the fourby now.
I'm hoping I'll get better grip with them than the crxp I got on the fourby atm.
I'll post the outcome here.
Thanks guys.

[Bigcol]

yeah, your front ones are shot
and the back ones are only good as spares - really........

the Coopers do look better,
put the two BEST tread ones on the front - for steering
then the next two best on the back
pick the best of the rest as your spare

[dom14]

yeah, your front ones are shot
and the back ones are only good as spares - really........

the Coopers do look better,
put the two BEST tread ones on the front - for steering
then the next two best on the back
pick the best of the rest as your spare

Thanx mate. I'll have to get into it through the week.
I realize now the front ones are pretty bad & I shouldn't have put them on at all.
I obviously gota pretty bad deal with the tyres. But, learnt a pretty valuable lesson beyond my loss.

BTW, I'm trying to troubleshoot an apparent electrical issue with the fourby atm.
So, far I haven't been able to locate the culprit.
If you have time, please have a look at this thread, and see if you can give me few tips.
I bet this isn't an uncommon problem with RB30 Patrols.

http://www.patrol4x4.com/forum/auto-electrical-37/fuel-system-problem-rb30-patrol-267785/#post3940465

[Bigcol]

trust me I know a bit about 2nd hand tyres........

I once paid $400 (that I had to borrow) for 10 tyres that were no better than your back ones.......

all up, they lasted about 10 months, so to me at the time, it was a good deal

now the benefit of old age and ?wisdom? I wouldnt do it again

[Bigcol]

well now, many years ago, I had a 4.2 petrol/gas
and I was having problems with it

sometimes it would start & run ok in petrol - but not gas
sometimes it would be running in petrol no problem, then Bam cut out and not re-start

sometimes it would start and run on Gas - but not petrol
sometimes it would be running in gas no problem, then - Bam cut out and not re-start

replaced EVERY sodding relay

when I asked a fine Gentleman in the Western Patrol Club on a drive one day, ET to be precise
he suggested......... (no, not get stuffed)

the Tacometric Relay - which switches power to and from the fuel / gas solenoids..............

replaced that........

but at the same time, my mate and I found another problem

the Earth for the Electronic Ignition was almost completely stuffed
so at the same time, I went and replaced ALL connections for the Gas / Petrol system


and never had a problem again

I also had -
2 earth straps off the main battery
2 earth straps off the 2nd battery
1 earth strap from the Gearbox to the Chassis
and 1 earth strap from the Motor to the Chassis



some food for your thoughts, and also some minor wiring checking for you to do............

[dom14]

well now, many years ago, I had a 4.2 petrol/gas
and I was having problems with it

sometimes it would start & run ok in petrol - but not gas
sometimes it would be running in petrol no problem, then Bam cut out and not re-start

sometimes it would start and run on Gas - but not petrol
sometimes it would be running in gas no problem, then - Bam cut out and not re-start

replaced EVERY sodding relay

when I asked a fine Gentleman in the Western Patrol Club on a drive one day, ET to be precise
he suggested......... (no, not get stuffed)

the Tacometric Relay - which switches power to and from the fuel / gas solenoids..............

replaced that........

but at the same time, my mate and I found another problem

the Earth for the Electronic Ignition was almost completely stuffed
so at the same time, I went and replaced ALL connections for the Gas / Petrol system


and never had a problem again

I also had -
2 earth straps off the main battery
2 earth straps off the 2nd battery
1 earth strap from the Gearbox to the Chassis
and 1 earth strap from the Motor to the Chassis



some food for your thoughts, and also some minor wiring checking for you to do............

Thanx Bigcol. That was very helpful indeed. I'm onto the business of replacing+cleaning all the earth wires(I have been onto it for a while, then got slack when the fourby was going good). It looks like I have a major electrical inspection job for fourby. I won't be taking it on any trips until that's done.