Odd tyre size?

AussieAub · #1 (**permalink**) 12th April 2009, 11:25 AM

Hey guys,
After having a side wall ripped open to a rear tyre yesterday, by an exposed rock on a sand track, I had to swap with spare. The 4 tyres on the Disco were 245/70x16, but the spare is a 235/70x16. Obviously its on now as I had no other choice. But HangOver mentioned something about "diff wind up", something I'm not familiar with. Would this, what I consider a small difference in wheel circumference, give me any major issues?

We are due to go away down to Bridgetown for a few days (no 4WDing, just some site camping), in a few days time. Do you reckon its safe to leave this spare on, or should I be doing all I can to get replacements before hand? I would assume I need to replace both sides due to uneven wear?

Anyone NOR have a decent contact for tyres? VERY tight budget right now....!!

Any help/advice appreciated.

Cheers,

..:: KIEREN ::..
2000 Disco II Auto V8
Object Of Mass Consumption

dullbird · #2 (**permalink**) 12th April 2009, 11:32 AM

I would be replacing the tyre.....235.70 is the standard that a lot of disco's came out with not good of the person that changed to 245's and didn't change the spare.

its not good for the car to have such a variant in rolling diameter between the to wheels..
change it as soon as you can

AussieAub · #3 (**permalink**) 12th April 2009, 11:35 AM

Thanks for that mate.
Yeah, unfortunately the Disco came with the 4 bigger tyres and original spare when I bought it. Something I always knew about, and one of those "I'll get round to changing that one day" things.

Now its too late. Bugger!

Cheers,

..:: KIEREN ::..
2000 Disco II Auto V8
Object Of Mass Consumption

dmdigital · #4 (**permalink**) 12th April 2009, 11:40 AM

245/70R16 is the next size up but definitely not a common size. It will fit a D2 as easily as the 235/70 so no need for suspension lift etc. What DB said stands, I'd not drive it much until you get a 2 new tyres to mach the other 3 (or 5 new tyres that match).

Lotz-A-Landies · #5 (**permalink**) 12th April 2009, 12:32 PM

As an alternative fix for the short term you can use your rolling radius to adjust the air pressure in your car. A higher pressure in the 235 and lower pressure in the 245s adjusted to give you the same height from the hub to the road when hot.

The 235 should be on the rear and not the steer axle.

Diana

dullbird · #6 (**permalink**) 12th April 2009, 01:38 PM

Quote:

Originally Posted by dm_td5

245/70R16

Quote:

is the next size up but definitely not a common size.

It will fit a D2 as easily as the 235/70 so no need for suspension lift etc. What DB said stands, I'd not drive it much until you get a 2 new tyres to mach the other 3 (or 5 new tyres that match).

I was sure that some disco's got released in 245/70

the later D1's

I could be wrong on that of course

dmdigital · #7 (**permalink**) 12th April 2009, 02:11 PM

Not in Australia at least. The D2's did come with 235/70R16 and 255/60R18 which are near enough to the same diameter. Coopers and others now make a 255/70R16 which they will tell you is suitable for the Disco - I had these on my D2.

The difference in diameter between 235/70 and a 245/70 or 255/70 is 15mm or 28mm respectively. The overall diameters are: 29", 29.6" and 30.1".

slug_burner · #8 (**permalink**) 12th April 2009, 05:08 PM

get two replacements and relegate the 235x70 to ebay or a trailer and put the surviving 245X70 onto spare tyre duty.

I would try to get that 235x70 off the car soon without panic but I would not go on holidays with it on the axle.

lambrover · #9 (**permalink**) 12th April 2009, 05:25 PM

you won't get wind up unless the center diff lock is on, the differental action will allow for the differance in diameter just as when you go around a corner one wheel is going faster then the other, but if you could imagine the diffs would be doing double time and a half to allow for this and this puts heat and stress on the diffs not good. someone said letting the tyre pressure down on the other tyres could work but remember that lower tyre pressures at highway speed give bad handling and the tyre temperature increases and you can delaminate the tyres so go slow I would say no faster than 70k on the bituman.

AussieAub · #10 (**permalink**) 12th April 2009, 09:58 PM

Cheers all.
Decision made to get new tyres on the rear before any haul, long or short.

Now the decision. Do I get the same 245/70's and have a "difficult size" to get hold of in an emergency? Somebody here (and I won't mention names yet!) reckons I can get standard Deefer size tyres to fit, but can't remember what size off hand. These are a much more common size, and will defo fit with the +2" springs recently fitted, with no issues, and give me more clearance to the diffs.

Any one any rough ideas on cost differences, and of course - and I know irts been done to death elsewhere - but any recommended tyres?

Cheers,

..:: KIEREN ::..
2000 Disco II Auto V8
Object Of Mass Consumption

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