Did 2001-2006 Z71s come with a 16 or 17 inch spare?

I just picked up a set of used Z71 wheels and tires (265/70-17s)to put on my LS whichcurrently has265/70-16s including the spare.

Did the Z71 come with a matching size spare?

I havea track lock or power lock rear diff, which I belive needs matching spares, but I'm not sure.

Thanks,

- Dan

 

Don't know about Z71s but all you need to be sure is that the OD of the tire/wheel combo is the same. Hope this helps.

 

Thanks.

I was pretty sure the diameter needs to be the same or it would eat up the limited slip clutches.

I'll start looking for a matched spare.

 

What "limited slip clutches"?

 

from here: http://www.chrismans.com/AskSpankyDiff.html

Eaton’s Hybrid limited slip/locker (Gov Lok) which is a factory rearend option in many GM built trucks. The Eaton G80 Locking Rear Differential. This automatic unit, available for rear drive and 4-wheel drive vehicles, makes traction problems a thing of the past. The Locker makes towing large boats and campers a breeze. The Locker is a speed sensitive design. That is, it reacts to wheel slip by sensing when one wheel is spinning substantially faster than the other. So, when you're cruising along on clean dry pavement, the locker operates like any regular open differential. But, as soon as wheel slip happens, going forward or reverse, the locker immediately kicks in. Here's how. The differential is set up with a flyweight governor that responds to differences in wheel speeds, and disc packs that are mounted between the side gear and the case. When one wheel is spinning substantially faster than the other, the governor spins rapidly, causing the flyweight to open. That flyweight then catches on a latching bracket and the lockup process begins. During lockup, a self-energized clutch system causes a cam plate to ramp against a side gear. This ramping action compresses those disc packs mentioned earlier. The ramping continues until both axles - and therefore both wheels - are spinning at the same speed. This is full lock, and it prevents any further wheel slip. (Note: Axle lockup can only occur at speeds below 20 mph.)

After reading about the the locker/LSD, it isa different design than I thought it was, but I still think it would be bad to have a mis-matched diameter spare and have it think one tire is slipping. I don't know what the tolerance is for different diameters, but my current spare is over an inch less.

 

Hi guy's. I just bought a 07 Z71 that came with 18's and has a 17" spare. I do believe the overall height of the 17" spareand the 18's are the same. The 17" wheel has a taller sidewall.

 

Even on a non-limited slip/locking rear end, disimiliar tire diameters will accelerate wear in the differential by causing the spider gears to always be rotating, even when going in a straight line.

 

GM includes a spare that is the same (within 1mm) overall diameter as the stock tire/wheels package.

For those of you that have up-sized your wheels and tires don't fret, you can continue to use the OEM spare tire (even though it may be smaller), it will not harm the front or rear differential even though it will cause the planetary gears to turn slowly as pointed out above (they actually do spin 99% of the time during normal use any how) it will not damage anything provided that you use the spare only for short distances at moderate speeds and do not tow with it.


Several years ago GM switched to a full synthetic rear axle gear lubricant and a low friction Hypoid gear cut that reduces heat and wear of the rear end, these changes have substantially enhanced the durability of the rear-end.

 

Do they actually spin or just move some since you can't travel in a perfectly straight line? Just curious.