jeepmedic46
Expedition Leader
One of my tires blew up and I had to use the spare. The spare is a 235/75/17 and the other 3 are 265/70/17. We're suppose to be getting up to 40" of snow. If I use my 4 wheel drive will I damage it?
4 wheel drive with a smaller tire
- Thread starter jeepmedic46
- Start date
4x4x4doors
Explorer
You're talking less than an inch difference in overall diameter and you're driving on snow, shouldn't be a problem
jeepmedic46
Expedition Leader
Thank you, I just wanted to make sure
jeepmedic46
Expedition Leader
I don't have a locker, should be fun,
Joeprunc
Observer
I see your user name is Jeep medic. A lot of Jeeps are full time 4wd, is your vehicle a full time 4x4? If so I would say yes you have a change of damaging your drivetrain as you are probably also driving on dry pavement.
It should not be an issue if you are on snow, packed snow, or ice, as the slick road will allow the tires to slip and accommodate for the difference in tire heights. But you cannot think of 1" height difference, you have to think of the circumference, essentially every rotation of your 32" dia. tires, your spare tire (31" dia.) will rotate 3 1/8" less. This can damage your drivetrain in 4wd if your wheels cannot slip/spin. When driving in 4x4 with open differentials, usually cross wheels provide power, so yes you can possibly damage your drivetrain if driven far on pavement.
If possible I would only put it in 4x4 when conditions are slick.
It should not be an issue if you are on snow, packed snow, or ice, as the slick road will allow the tires to slip and accommodate for the difference in tire heights. But you cannot think of 1" height difference, you have to think of the circumference, essentially every rotation of your 32" dia. tires, your spare tire (31" dia.) will rotate 3 1/8" less. This can damage your drivetrain in 4wd if your wheels cannot slip/spin. When driving in 4x4 with open differentials, usually cross wheels provide power, so yes you can possibly damage your drivetrain if driven far on pavement.
If possible I would only put it in 4x4 when conditions are slick.
stioc
Expedition Leader
As long as the diff is open it shouldn't be a problem. Spare donuts on cars are smaller than the rest of the tires and they're fine.
For additional peace of mind on pavement if you have manual hubs on the front- unlock the hubs, throw the smaller spare there and keep the same sized tires on the rear.
For additional peace of mind on pavement if you have manual hubs on the front- unlock the hubs, throw the smaller spare there and keep the same sized tires on the rear.
jeepmedic46
Expedition Leader
It was a old tire and blew up while I was driving home from a paramedic refresher. The truck is a 05 f150. I had to give up my jeep for something that could pull a horse trailer
I agree with Joeprunc as I have changed diffs because of miss matched tires on 4wds as part of my job.
Also a note the little donut tires will say up to 50 miles and not over 50mph is because the diff will start to over heat drive axles.
jeep-N-montero
Expedition Leader
One bit of advice is run the 3 matching sizes at 25psi and the odd tire at 35-38psi, I had to do this once to get off a trail and down the road back into Moab.
jeepmedic46
Expedition Leader
Going to try and get the right size tire from the junkyard today. Hoping my taxes come in this week so I can get new tires. Ex wife has been sick and been helping her out so money is tight
digitaldelay
Explorer
That's a pretty good idea, never thought of that!
Also good advice. Even a limited-slip rear axle could be damaged. Maybe check your door jamb plate for the axle code.
19 – 3.55 Non-LS
18 – 3.08 Non-LS
H9 – 3.55 LS
B6 – 3.73 LS
Jason