using your spare tire????

[goodguys75]

if I were to use my stock spare tire, and I have different size tires on my truck 285/70/17. . I have heard that it can damage your rear end... . Is this for long term use... . or would i be ok for an emergency... ... . never had to use my spare, but i just thought of this... . thanks for any input

 

[Bessler]

Put your Spare up front and rotate the front to the rear if you get a rear blow out.

 

[HBarlow]

Using different sized tires on the rear or any drive axle causes the differential to work full time spinning the spider gears as if continuously going around a circle track because each wheel and axle is spinning at a different speed. This generates heat and additional wear on the small spider gears in the differential.

For traveling a long distance it is likely to cause damage. To get to the next town to replace or repair a tire traveling at a moderate speed it is unlikely to cause damage.

 

[goodguys75]

Put your Spare up front and rotate the front to the rear if you get a rear blow out.

thats a good idea... . thanks... I knew there was some sort of issue with the rear end if i did run a stock spare.....

 

[ScottLewis]

Since you have a 4X4, the same considerations apply for the front axle. Some older vehicle have lockout hubs which wouldn't be impacted but ours acts virtually like the rear.

 

[Motorhead]

Since you have a 4X4, the same considerations apply for the front axle. Some older vehicle have lockout hubs which wouldn't be impacted but ours acts virtually like the rear.

I agree about the front axle but at least the front axle, on dry pavement isn't transmitting power to the ground.

 

[Road Dog]

If the rear is limited slip then different sized tires will generate a lot of heat. In the front it doesn't matter. Every turn you make spins the spider gears.

 

[HBarlow]

The front axle of a 4x4 matters just as much as the rear differential if the question is, "can I use different sized tires on the same axle?"

The fact that the transfer case is in neutral means nothing to the spider gears spinning continuously as the front wheels roll.

The comparison the the front axle being a steer axle doesn't matter much either. Making turns or going around curves is temporary and for a short period of time. Driving 50 miles home or to the next town for a tire repair or replacement is a long distance to travel with the differential spider gears working continuously.

The mention of a limited slip front differential is valid but I didn't think Dodge Rams have limited slip front axles.

 

[rscurtis]

Keep in mind that on the 2nd generation trucks with the front axle disconnect, the spider gears are spinning continuously at wheel speed without any harm at all.

 

[Regcabguy]

The front axle is an "open" differential. It's the lesser of evils until you fix that flat. Regardless,it's no substitute for a same size spare.

 

[dodgesst]

what about OEM space savers? they are smaller diameter than stock tires. They are factory installed. a few of my Dodge trucks have smaller spare tires from the factory.

 

[Road Dog]

The comparison the the front axle being a steer axle doesn't matter much either. Making turns or going around curves is temporary and for a short period of time. Driving 50 miles home or to the next town for a tire repair or replacement is a long distance to travel with the differential spider gears working continuously.

I drove 1,000km with mismatched front tires in 2WD and 4WD (hunting trip) with no issues. It was only a 1" difference in diameter but a new tire would have a larger diameter compared to the worn tires I had. Back home I bought a used tire with a matching tread depth. That was so I could rotate it to the back without worrying about the limited slip.



(I ripped a hole in the sidewall making a repair impossible. )

 

[DennyDay]

The front axle is an "open" differential. It's the lesser of evils until you fix that flat. Regardless,it's no substitute for a same size spare.

I agree with everybody about the same size spare but my 01 had a vacuum operated interconnect on the front axel which would take care of the spider gear problems. My '06 doesn't have this feature, but the SpynTec Kit took care of th problem - - but I still wouldn't run very far with different size tires on the front. Pretty sure it would effect the steering.

 

[GaryCarter]

Lots of 4x4's have a disconnect in the front axle. So the pinion does not spin in 2wd, but the spiders are running continuously because one wheel is driving the side gear into the diff.



If I have a flat the spare goes on the front and I keep the same size on the powered rear.

 

[HEMI®Dart]

Mine lasted about 10 years..... then it was stolen.

 

[Regcabguy]

what about OEM space savers? they are smaller diameter than stock tires. They are factory installed. a few of my Dodge trucks have smaller spare tires from the factory.

Our space saver spare on the Honda is the same diameter,just skinnier.

 

[HBarlow]

Keep in mind that on the 2nd generation trucks with the front axle disconnect, the spider gears are spinning continuously at wheel speed without any harm at all.

I don't have a differential diagram or mental picture handy right now to review differential operation in my mind but my initial thought is that I don't think the spider gears are turning much when the axles are running at the same speed. The spider gears begin turning when the axles are rotated at different speeds IIRC.

 

[HBarlow]

Put your Spare up front and rotate the front to the rear if you get a rear blow out.

This is, in my opinion, the best advice. Some may get away with running different sized tires on the same axles for extended periods of time but I would not recommend it. Excessive wear will eventually show up. I can't predict when.

 

[EricBu12]

Exactly why when I went to 19. 5" tires, I bought a spare as well. When I change the tires to winter, I change the spare as well.

 

[HBarlow]

Yep, the Boy Scout motto, "be prepared. " It continues to work, even for us old men.