Noooo! Don't do it. I came on here and asked pretty much the same thing a while back. Everybody on here told me dont do it except for one of my buddies. I listened to him and destroyed my front and rear diffs along with the coupler. Costed me a lot of $$$. I was running 3 36's and one 35 for a few days. I understand our trucks our tuff but go find a matching spare. I promise it's not worth it. That was the biggest cruiser lesson I learned.. RUN ALL TIRES THE SAME SIZE or your Cruiser will teach you what I had to learn.
Wow. Did your dog die and your daughter get pregnant too?
Posts like this offer zero information and perpetuate rumors. Unless your drive train has serious issues beforehand, running 1 tire 1" smaller is not going to destroy everything on your truck. I call bull****.
Wow. Did your dog die and your daughter get pregnant too?
Posts like this offer zero information and perpetuate rumors. Unless your drive train has serious issues beforehand, running 1 tire 1" smaller is not going to destroy everything on your truck. I call bull****.
As soon as you run different sized tires on the same axle your differential actually has to start working. I trust you know when I say differential I mean your "spider gears", its a very common thing for someone to call the entire carrier, gears and diff.....a diff. The spiders will never turn unless... You're turning or you a running different sized tires. The bearings are only tin and are never meant to take constant friction and will burn up quickly
So yes running a different sized tire for prolonged amounts of time will start to destroy things. But if only to move it 50ft like said before it won't do a thing.
OK. Fine. So what you're saying is that the roads are perfectly straight, perfectly even, tires are exactly the same size.
The truth is that your spider gears are always turning inside the carrier. There is always a difference between left and right wheel speeds. The only place this isn't true is in laboratory conditions.
Wow. Did your dog die and your daughter get pregnant too?
Posts like this offer zero information and perpetuate rumors. Unless your drive train has serious issues beforehand, running 1 tire 1" smaller is not going to destroy everything on your truck. I call bull****.
Bull****? Go run different sized tires an inch different for several days and see what can happen. I gave all the information you needed. My drive train was in perfect operation before. You calling me out is ignorant. I know what happened and the wrong size tires were the root cause. I really want you to test it out since your so confident..
And again you provide no information regarding the catastrophic failure.
While it may seem that I'm being a smartass, what you said was, "I had my entire driveline explode because of a 1" diameter difference in 1 tire." You gave no details of what was found, what was done, or anything else. You may have well blamed it on the ambient temperature.
The difference between a 36" tire and a 35" tire equates to approximately 22 revolutions per mile. That's a 4% difference. If this was truly the case then a long windy road would mean certain death.
It could be different for FJ80s and FZJ80s. I don't think that a 1 inch difference would be a big problem for 80s that lack a VC, but if this tire size difference can cause the VC to sieze, then it could cause big problems like a stripped front pinion. I would like to hear from more people that have had siezed VCs, because even a small difference in rotational speed could put a lot of stress on the driveling in the absence of a functioning center diff.
Have you considered buying a new or used 255/85R-16 tire as a spare? It measures out as a 33 inch tire and would gain you some ground clearance (about 1 inch) under the rear end.
The 80s system can handle a bit of mismatched tire for a bit of time and miles. If everything is in proper working order (fresh fluids, etc) you can use it as a spare to get to civilization though keep the speeds down as a matter of practicality. Blowing down the freeway at 80 pulling a trailer for 4 hours would just be foolish for instance. 50 with the flashers on would be prudent, for example.
When buying a spare, consider bringing a tape measure and checking the circumference. The same size tire from different mfrs can vary quite a bit. Toss in some wear, and you're best to measure yourself.
I think a grenaded drivetrain would be a combination of issues, though.
Just a thought on this... but if this was such a problem, wouldn't new tries on one axel vs. used on another cause this 'grenade' to go off? If you think about the possible tread difference between even the same-sized new vs. 'almost bald' tires (which I can see as being a common thing out in the pavement land), I would imagine you might end up in a 1-2% difference range. Which, just by the numbers, would mean you'd have the same overall stress on the drivetrain on a mis-match (at the center) as a 4% difference, just over a longer time.
Take that example to the extreme, and even a minor variation in tread wear could cause the VC to die. I'm not buying it.
I wonder about this also. I know of two Landcruiser that are way over abused. One was a customer of mine. He's had the truck since new it has 550,000 and he said he has only had the oil changed and a tune up. Never any gear oil changed never done bearings or axle service, he said he didnt know he should. The other is at the gas station by my job and the clerk also has owned it since new and swears he hasn't changed the oil in at least 10 years and defiantly never done any other maintenance. These trucks are way tougher than we give them credit for. We here love and cherish them and would never neglect our trucks like that so I think we over analyze what may have caused a failure. I can't see how a few percent difference in rotational speed of a tire for a day or three could cause a catastrophic failure of the whole drive train. I could however see how someone could buy the uncared for rig from the gas station clerk without knowing its true history, then began to care for it and all of a sudden there's a real problem that gets blamed on the wrong thing. Maybe I'm wrong but also this is about a spare tire for temporary use not continually running different size tires which I wouldn't do but to get me home I think I'd risk it.
