How far/fast can i drive with mismatched diameter tires? (1 Viewer)

[baltik]

Blew drivers rear tire going down a rough trail - spare is 30.5" in diameter, rest of the wheels are 32.6". All tires will be replaced so not worried about uneven wear but worried about ruining transmission etc. Would a 200 mile trip at 65mph cause permanent damage?

 

[McDuff123]

Can’t speak for anyone else, but I wouldn’t do it.

 

[Braden620]

Maybe, if you can deflate the 3 larger diameter tires and over inflate the smaller one to try and get the diameters to match. Put the smaller one on the front. IM not familiar with the 100 series but if you can unlock the hub on that smaller one do it.

 

[jLB]

If your vehicle is 2000-2007, I'd be more concerned with VSC or ATRAC kicking in at 65MPH, and sending you into a ditch...

It's hard to believe that there's not a tire shop somewhere in that 200 miles....

 

[JunkCrzr89]

Blew drivers rear tire going down a rough trail - spare is 30.5" in diameter, rest of the wheels are 32.6". All tires will be replaced so not worried about uneven wear but worried about ruining transmission etc. Would a 200 mile trip at 65mph cause permanent damage?

It’ll be fine in AWD. Diffs are open. But like @jLB said, the VSC may kick in. Put the little one on the rear, because VSC kicking in on the front on dry pavement is zero fun.

 

[Braden620]

It’ll be fine in AWD. Diffs are open. But like @jLB said, the VSC may kick in. Put the little one on the rear, because VSC kicking in on the front on dry pavement is zero fun.

Can VSC not be disengaged or turned off? Putting the small one in the rear GUARANTEES there will be extra rotations occurring in the spider assembly. If he puts it in the front with an unlocked hub, no rotation of the differential will occur at all, and thus no extra heat buildup will occur.

 

[JunkCrzr89]

Can VSC not be disengaged or turned off?

Yeah, If you don’t mind cutting some wires…

If he puts it in the front with an unlocked hub, no rotation of the differential will occur at all, and thus no extra heat buildup will occur.

How do you propose he unlock the hub without manual hubs or a spool in the t-case? I suppose he could cobble something together like @ramangain did to keep the CV from pulling out and banging around. Not everyone has Forger’s tool (or similar) or the tools to remove the CV axle, hub flange, or front driveshaft with them. Maybe he does, I dunno.

Putting the small one in the rear GUARANTEES there will be extra rotations occurring in the spider assembly.

The 100 series is AWD when the CDL is not locked. It really makes no difference if the smaller tire is on the front or rear because both differentials function the exact same. But the smaller tire could cause the VSC to kick in, which, on dry pavement, could prove dangerous if the smaller tire is on the front.

 

[Braden620]

Yeah, If you don’t mind cutting some wires…



How do you propose he unlock the hub without manual hubs or a spool in the t-case? I suppose he could cobble something together like @ramangain did to keep the CV from pulling out and banging around. Not everyone has Forger’s tool (or similar) or the tools to remove the CV axle, hub flange, or front driveshaft with them. Maybe he does, I dunno.



The 100 series is AWD when the CDL is not locked. It really makes no difference if the smaller tire is on the front or rear because both differentials function the exact same. But the smaller tire could cause the VSC to kick in, which, on dry pavement, could prove dangerous if the smaller tire is on the front.

When I said I wasnt familiar with the 100 series I meant it. Carry on fellas.

 

[jLB]

Can VSC not be disengaged or turned off? Putting the small one in the rear GUARANTEES there will be extra rotations occurring in the spider assembly. If he puts it in the front with an unlocked hub, no rotation of the differential will occur at all, and thus no extra heat buildup will occur.

There’s not a “VSC Off” button, but disconnecting a wheel speed sensor should disable the system.

The standard US model 100 series doesn’t have locking/unlocking hubs.

If you’re crazy enough to try this, I’d sure as hell prefer running the undersize tire on the rear axle, opposed to fighting with the steering the whole way home.

From my perspective, the correct answer would be to have had a correct or near correct size spare to begin with. The next best solution would be to drive slowly and carefully to the nearest tire shop, and beg, borrow, or steal, a new or used tire, that is somewhere in the ballpark of the correct size.

 

[JunkCrzr89]

From my perspective, the correct answer would be to have had a correct or near correct size spare to begin with.

Indeed

 

[ga12r1]

How fast will she go?

 

[baltik]

I too would have preferred a full size spare… and a complete tool kit for lowering said spare. Alas, certain things you discover after a used car purchase. Point taken, will limp her at low speeds and pick up some ko2s. On a semi related note, will a 275/70 ko2 fit in the spare location

 

[jLB]

I too would have preferred a full size spare… and a complete tool kit for lowering said spare. Alas, certain things you discover after a used car purchase. Point taken, will limp her at low speeds and pick up some ko2s. On a semi related note, will a 275/70 ko2 fit in the spare location

“275/70” is missing certain rather critical key information…

My 99 LX470, and my son’s 00 LC came from the factory with 275/70R16 (~31” tall), and the spares fit just fine.

My 06 LX470 is currently running 275/70R18 ( ~33” tall) KO2s, and it’s tight, but it does fit. If you’ve got the ~05ish LX470 “in bumper” hitch, it might be even tighter than what I have.

 

[medtro]

Are you solo? Can you borrow a bigger spare from your group if you are not solo?

 

[Njck22]

Put it on the front, pull both drive flanges and front drive shaft. Lock the cdl and vsc and trac will be disabled. I seriously think you will overheat your diffs doing it any other way.