Would my diff be damaged?

[Mr Plough]

After driving for 10000ks i noticed that some turkey at the tyre shop has fitted different sized tyres on my 100 series. On the front axle one side has a 285 75R16 (correct) and the other side has a 265 75R16 (incorrect). I realised this when fitting chains for the snow & one chain was very loose. There is approx 30mm difference in diameter. Does anyone know if my diff would be damaged or unduely worn due to this stuff up? I realise that the diff has been acting as if it was going around a corner that lasted 10000km.

[Patrolling Paddy]

Is it constant 4wd?
Does it have auto or manual hubs?

If it is constant 4wd then it has the potential to do some damage as although the diff is designed to allow for cross axle differential it isn't really meant to do it for 10000km at a time. If this is yours then it would pay to get it checked to make sure you don't run into problems when you need it most.
If it has auto hubs then the same applies it has the potential, so get it checked.
If it has manual hubs that have been in the free position then the diff is not engaged and no damage is possible.
Hope this helps some.

Cheers

PP

[grimbo]

hang on you drove for 10 000km and had never noticed the different tyre sizes? You never noticed any wobbles, handling issues etc or never let your tyres down etc

As to damage only if you have been driving it in 4wd on the road, which you shouldn't be doing. i can't imagine there would be any damage.

Don't know how you are going to be able to get the tyre fitters to replace the tyre after this long

[Harb]

Is it constant 4wd?
Does it have auto or manual hubs?

If it is constant 4wd then it has the potential to do some damage as although the diff is designed to allow for cross axle differential it isn't really meant to do it for 10000km at a time. If this is yours then it would pay to get it checked to make sure you don't run into problems when you need it most.
If it has auto hubs then the same applies it has the potential, so get it checked.
If it has manual hubs that have been in the free position then the diff is not engaged and no damage is possible.
Hope this helps some.

Cheers

PP

x2 , if the hubs where engaged the differental gears may have been turning, but to be honest low tyre pressure on one side makes that happen, so the result may not be quite as bad as you think....... look for metal in the diff oil.....it will make the oil look like metalic paint.
The diff gears do turn as you corner and there are very very few dead straight roads, so I recon although this is not ideal, you will be ok.

cheers

PS if your wife asks, the diff is stuffed and now you will be needing to replace both ends because they are "matching" :p with ARB lockers....:thumb:


.

[Mr Plough]

Amazing, but it has always driven straight, even now with the correct size spare on it drives straight. When i lower my presures down or pump my tryes back up I dont generally read the size of my tyre to know how much air to put in! :-) its a constant 4wd

[GeeYouFaw]

I didn't think that having 1 tyre narrower than the other would do any damage?
Spacesaver spare maybe :)

[trity]

I didn't think that having 1 tyre narrower than the other would do any damage?
Spacesaver spare maybe :)

it may seem it is only the width that is different but the height in the side wall is a percentage of the width so to speak so a 265 75 16 will be slightly smaller in the sidewall than a 285 75 16 therefore the rolling diameter of the two will be different

if i was you i'd di a diff oil change and see if any shavings come out if not it will mean all ya teeth should be fine if ya see a few shavings that will mean that your teeth may be a bit smoother than before

[toy yoda]

Amazing, but it has always driven straight, even now with the correct size spare on it drives straight. When i lower my presures down or pump my tryes back up I dont generally read the size of my tyre to know how much air to put in! :-) its a constant 4wd

If it drove straight like that how far will it pull with equal tyres:D

as Trity said the 75 or profile of the tyre does not equate to a relative size it is a ratio of the width.
If it has been used on the bitumen at speed then the possibility of damage is there, i think harb said check oil for crap, might be a good time for adrain and re fill and have a look at the oil for signs of OH no's. You may not have done any damage yet but you certainly may have reduced its life expectancy

[sudso]

If your front diff is an open one it wouldn't do any damage in 4wd except use more fuel than normal probably.

[Peter @ Aawen4x4]

You've probably cut about 1/poofteenth off the life of the centre diff and the front open diff! Next oil change, do the check for filings etc, but being Toyota diffs, probly not much different to normal anyhoo, so it won't have bothered it too much!

Driving with it in constant 4WD will only be a minor irritant, but locking the centre diff and working it on hard surfaces, or even just in normal 4WD conditions is way more likely to have created issues!! How much 4WDing have you done during that time??

[trity]

being constant 4wd on the black top it is normall front 30% drive rear 70% drive instead of a direct 50/50 so i think as Peter said minimal damage but check the oil just in case