Spare tire is different size

[lionvt]

I bought my 95 Disco I used and the previous owner had put 245/75/16s on them. Although I liked the way it looked, I didn't like the occasional rubbing on the fenders. So because those tires had worn out, I just put stock 235/70/16s on....forgetting that the spare is a 245/75/16.

So am I asking for trouble? If I had to put the spare on would the inch difference in these tire sizes cause havoc with the drive train or handling? Should I buy a spare in the 235/70/16 size or am I worrying for naught and can keep the money for beer?

I would not keep the spare on permanently -- just limp to the tire shop with it.



I'm not sure why this posted twice. Please disregard the other post.

 

[barefoot]

i dont see much of a prob as long as you are indeed using it only to limp! long term issues would include an f'd up wear pattern on the others. also, be aware of the handling/stability issues if u do have to limp with it!

 

[Rocky]

Limp to tire shop would be ok, assuming no trutrac or detroit. but understand that you are making the diff work very hard compensating for the different diameter of each tire.

 

[rmuller]

Go to a tire shop and see if they have a used 235/70/16 in good condition... half the time they'll give them to you.

 

[SCSL]

On a full-time 4x4 rig you are better off keeping consistent tire size,,including spare. I 2nd the notion of trying pick up, at the least, a used spare same size as the rest.

 

[Joey]

I would not use the larger spare for more than a support of the vehicle while you walk to a tire shop with the bad tire and get it fixed... unless you like spending more morey on repairing things like the transfer case.

 

[p m]

if your diffs are open (center and axle), you can drive with one 235/70-R16 tire as long as you care to. It will result in no negative effects on anything.
You should not drive with a different-sized tire if you have axle lockers or locked center diff - that'll lead to broken things quickly. TrueTrac won't care much about different-sized tires, but you will feel the fairly strong pull sideways.

FWIW - the new JGC has a transfer case with uneven torque split front/rear; this is accomplished by having a planetary gear set on one of the outputs. Therefore, the center differential is rotating all the time, and there have been no reports on premature wear.

That said... I'd hate to drive a Disco with 245/75 on one side and 235/70 on the other...

 

[cmoore207]

I second the used tire route. I got my spare for "free" but the shop charged $20 to remove my factory spare tire from the rim and mount up the new-to-me spare. Still, beats paying big $$$ for a brand new tire that there is no real reason to use. Plus, I sold the factory spare on ebay for $100. Sure, you could buy a new tire and deal with a 5-tire rotation, but why?

The caveat for me was that 255/70/16 seems to be a relatively rare size. The free used tire I got is not exactly a 255/70/16, but its close enough in diameter to get the job done.

 

[Roverlady]

I've got a stock 235/70/16 Michelin on my truck as a spare, and I'm running 245/75s......wanna trade?!

I have tried to find a used one at my local shop, but they never have anything when I'm there.

What kind of 245/75 tire do you have?

EDIT;
Just noticed you are in NM....would probably not be worth shipping the two tires to trade.
So, guess we will BOTH be looking for used tires locally.

 

[rmuller]

i dont think shipping a single tire should cost all too much.. check with fedex/ups.

 

[p m]

Sus, there are plenty of 245/75R16 tires around, including Michelin LTX. This size comes often as stock on half- and 3/4-ton trucks, and people ditch them often in favor of larger or more aggressive tires. PepBoys have Futura Daytona (IIRC) with a BFG/AT-cloned tread pattern.

 

[Roverlady]

Thanks Peter, I think my problem has been requesting only a BFG A/T in that size....though I thought they would be relatively easy to find as well. We're just in a small area....

 

[lionvt]

Just moved back to Vermont (Underhill) so the tire is now on the east coast. Drove without a flat from NM so at least I wasn't stranded looking for a tire shop in the middle of the country. I think I will mount a similar sized tire for the spare -- I was smart enough to hold onto the best tire from our 91 Range Rover when we recently put new tires on it. The Range Rover has always run stock tires so I have the extra tire that will match the new ones. I might do the 5 tire rotation thing and pay the $ to get one more to round out my new set of Pirelli Scorpion ATs in 235/70/16.

Of course now I have a solitary Pirelli Norseman in 245/75/16 that has never touched the road!

 

[frickjp]

if your diffs are open (center and axle), you can drive with one 235/70-R16 tire as long as you care to. It will result in no negative effects on anything.

Poor advice. There are three differentials involved, none of which are cheap. The diffs do not transfer irregular power on a regular basis, and are not designed to do so. Spider gears in the diffs have no bearings. They rely on small, intermittent movements to survive. Drive with an odd tire, and at least 2 diffs are churning until you fix the odd tire. 4 tires of the same size, and the internals in the diffs never move.
Do yourself a favor, dumpster dive and find a tire the correct size. Or send me some freight, and I'll go behind the building, dig one out of the pile and send it to you.
Here in WNY, snow eats many a diff due to one wheel spinning. Frozen transfer case shifters consume a transfer box diff form time to time as well.