Spare Tire question.

[ctluba]

I just mounted 285s on my H3 and did not get a 5th one for the spare. I still have the 265 mounted on the spare and plan to get the 285 on that next month. If I get a flat tomorrow can I use the 265 to get home or would that cause damage?

[wpage]

How far and how fast do you estimate traveling that way?

[ctluba]

Based upon info I gathered I plan to travel 0 miles at 0 miles per hour. I was told it would not be a good idea at all and would cause damage. I will just mount the larger spare. If I get a flat before then I call tow!!!!!

[wpage]

That correct. If you didn't your rig would be unbalanced and could be damaged dependent on variables.

[Texas Red]

Interesting. I was wondering the same thing if I go to 285's on my next set of tires.

[Dave92270]

that is interesting... Maybe my Hummer dealer is dumb, but when I was ordering my 285's (33") from them while ago, they suggested to keep the 265 (32") as a spare. I rejected the idea and got all 5 the same size, however I noticed the dealer actually sells some of their H3s with non-matching/smaller tire as a spare. I saw at least one H3 on the lot with four 285's mounted and 265 spare.

My guess is that slightly smaller (let say 1" difference?) spare is OK as long as one doesn't have to drive too far or for extended period of time?

[Viet Nam Vette]

I kwow that on a Corvette, it's a bad idea to mout a smaller diameter tire on the rear as a spare, as the Vette has a positraction rear axle. It would cause the the posi clutches to activate in the rear and burn them out while traveling in a straight line since one tire's outside diameter is smaller then the other.

In other words, the rear diff would think it's turning a corner. Now.if the H3's diff has posi clutches..it's a No-No..!! Not sure if the 3's diff's are posi..??

Are they..???

[Texas Red]

What about all those cars that come with a compact size spares? If I remember, they have a qualifier -- like "45 mph and 50 miles." I'm having trouble seeing how a 1" smaller diameter spare could be a problem if only used "sparingly". LOL.

[Viet Nam Vette]

Originally Posted by Texas Red

What about all those cars that come with a compact size spares? If I remember, they have a qualifier -- like "45 mph and 50 miles." I'm having trouble seeing how a 1" smaller diameter spare could be a problem if only used "sparingly". LOL.

I think those are still the same outside diameter as the oiginal tire...just thinner.

[RubHer Yellow Ducky]

Originally Posted by Texas Red

What about all those cars that come with a compact size spares? If I remember, they have a qualifier -- like "45 mph and 50 miles." I'm having trouble seeing how a 1" smaller diameter spare could be a problem if only used "sparingly". LOL.

you right, if its just for an emergency use the 265 till you can get the tire that went flat repaired. You just don't want to go hundreds of miles on the 2 different sizes...

[TXSUT]

Originally Posted by Viet Nam Vette

I think those are still the same outside diameter as the oiginal tire...just thinner.

Wrong, they are quite a bit smaller in diameter as well as being thinner. And worrying about using a 265 with 285s temporarily is just ridiculous.

[TXSUT]

Originally Posted by Viet Nam Vette

I kwow that on a Corvette...has a positraction rear axle.

Wrong there, too. Corvettes come standard with a limited-slip differential.

Don't think I've ever seen so much misinformation in one thread.

[Viet Nam Vette]

Originally Posted by TXSUT

Wrong there, too. Corvettes come standard with a limited-slip differential.

Don't think I've ever seen so much misinformation in one thread.

Wrong.. I own a 65 Corvette with a ZZ502 BB with Posi. Go on any Corvette forum and mention using a smaller diameter tire on one side on the rear with a Posi axle and see what kind of reaction you get.

And for your information .."Limited Slip" And "Posi Traction" are the same thing.

If you know how a posi works then you know that when one wheel slips, it slips against the internal posi clutches when traveling in a straight line. If you use a smaller diameter rear tire on a Corvette on one side of the rear, the clutches will slip all the time and burn up. Both wheels have to turn at the same speed to prevent the posi from engauging.



That's not missinformation ..But Fact


Don't think I've seen so much miss information from you.

[TXSUT]

Originally Posted by Viet Nam Vette

And for your information .."Limited Slip" And "Posi Traction" are the same thing.

That I know. I put my damn smilie face in the wrong place.

I was just trying to mess with you (GM stopped calling it a Positrac quite a while back), because even on a "positrac" rear end, using a smaller diameter tire for a short distance won't hurt anything....Vette forums be damned! LOL

I've owned 3 Vettes, so I know just a *little* about them.

[Viet Nam Vette]

Originally Posted by TXSUT

That I know. I put my damn smilie face in the wrong place.

I was just trying to mess with you (GM stopped calling it a Positrac quite a while back), because even on a "positrac" rear end, using a smaller diameter tire for a short distance won't hurt anything.

I've owned 3 Vettes, so I know just a *little* about them.

I've owned 9 Vette's in my time and hang on a Corvette forum where one of it's members is "John Z". John was a Drive Line Engineer back in the 60's and worked under "Zora" on the Corvette.

The spare tire topic came up once and went thru 2-3 pages. Most guys now use radial tires on there Mid-Years..(63-67) Corvettes. The problem is that that a spare radial doesn't fit flush in the spare tire carrier under the car. It hangs down due to it's thickness and in some cases it's diameter.

Someone posted the question about using a tire that was smaller in diameter then what he had on the car. John addressed what I have typed in regaurds to damaging the clutches. In other words...It's a Bad Idea.

Going a 100 feet or so might be ok, but remember...those clutches get hot fast and will burn up if the axle doesn't lock up.

When John Z talks..... Everyone listens..

[TXSUT]

This horse is dead.

While I have your attention though, let me thank you for your service to our Country...and I do mean that seriously and sincerely. (We need a US Flag emoticon on this website.)

Pete

[Viet Nam Vette]

Originally Posted by TXSUT

This horse is dead.

While I have your attention though, let me thank you for your service to our Country...and I do mean that seriously and sincerely. (We need a US Flag emoticon on this website.)

Pete

Thanks Pete... I Appreciate that, Thank You.

[tower]

Originally Posted by Viet Nam Vette

The problem is that that a spare radial doesn't fit flush in the spare tire carrier under the car. It hangs down due to it's thickness and in some cases it's diameter.

I guess that means you can't take your 'vette off road.

Originally Posted by Viet Nam Vette

thank you for your service to our Country...and I do mean that seriously and sincerely.x1,000,000

[Viet Nam Vette]

Originally Posted by tower

I guess that means you can't take your 'vette off road.

Only when you put your foot in it ..in first gear..Then your off road.

[tower]

Originally Posted by Viet Nam Vette

Only when you put your foot in it ..in first gear..Then your off road.

Rats!