hi...newbie here with a tire question!

Hi everyone.. first i'm from mexico and a proud owner of a jeep CJ-5 1976. and my question is.. right now i have 3 tires thornbird 30x11.50 R15 and then i took off one on the rear and put a pair of 32x11.50 on the rear so my jeep was on front 30x11.50 and back 32x11.50 the second time i went to the trail my automatic hubs broke.. a guy told me that, that happen because the rear tires were bigger thant the front.. well now i was looking for a 30x9.50 to put 3 tires 30x11.50 and 1 30x9.50 but i can find any here.. only i can find is 31x10.50 what can happen if i rool with 3 tires 30x11.50 and just one 31x10.50

Thanks a lot for your help. sorry for my english.

 

Welcome from Boston USA!

Your english is excellent.

On a four wheel drive (4WD) vehicle, you need for all your tires to be the same diameter. When you are in 4WD, all the tires are connected together by the differential gears and the transfer case. When you are moving straight ahead, all the tires must roll at the same speed, otherwise the gears will bind and something will break.

When you drive around corners, the outside tires spin faster than the inside, since the distance around the outside of the curve is longer than around the inside of the curve. If you use 4WD on pavement, your tires will bind as you go around curves - thus you should only use 4WD on loose surfaces like dirt or gravel roads. On dirt or gravel, the tires won't bind because of the slippage that's allowed by the loose surface.

So: 1) all tires must be the same diameter to use 4WD; there is no way around this.
and 2) only use 4WD on loose surfaces, like dirt or gravel - never on pavement.

hth!

 

Same thing with the gear ratios on the front and rear axles, they have to be the same ratio or things will break because the two axles will be trying to go different speeds.

 

welcome aboard from Michigan

These guys are right, make sure all 4 tires are the same size, otherwise things break.....like your hubs

 

Can't add anything to what these guys have already said except welcome from Eastern Washington

 

welcome from central NC

 

Oh yeah, welcome from Denver!

 

Thanks a lot for your help and post's would i be fine if i put one 30x9.50 (235/75) and three 30x11.50 ??

 

Welcome from central Va. Your english is better then most of my professors by far.

 

Probably not - the only way to be sure is to measure the height of the tires mounted on your wheels.

Be careful mixing widths of tires, because the size of your wheels will affect the height of different widths of tires differently. A 30x11.50 tire on an 8" wide wheel will have a different height than a 30x9.50 tire on an 8" wide wheel. All your tires must be the same height for 4WD to work properly.