31 inch tires no lift long term problems

[Leeroy38]

Hi everyone I know there's threads already on 31 inch tires with 15x8 wheels and no lift. I'm just wondering if anyone has had any long term problems with this set up. Thanks

 

[4rd4life]

long term problems... probably none. cons though, depending on what gear ratio you have vehicle will be a bit more sluggish as well as mpg loss, not much though. other thing to keep in mind if your putting wider wheels on is it might put a bit more stress on things like your hub bearings. but i wouldnt really worry about it. overall i think 31s fill out the truck nicely and i say go for it.

 

[Leeroy38]

Ok thanks for replying. Is getting the gearing changed worth it? I eventually wanna put some headers and a cam on it. Thanks

 

[Jeff213]

that depends on what your factory gearing is. if you have 3.73 gearing youll be ok, if you have a higher gearing you might want to change them.

 

[RangerX]

Yes, check and see what your ratio is. Too tall and it can cause accelerated death to automatic transmissions.

 

[geosnooker2000]

What about for 5.0L AWD? Is there any worry for those engine/tranny combos?

 

[4rd4life]

What about for 5.0L AWD? Is there any worry for those engine/tranny combos?

heat is the #1 reason when it comes to transmission failure. so if you change tire sizes or gears or overwork any other part in the drivetrain its not going to help regardless of engine size. you can try and add things like fluid coolers, but you should try and keep the tire/gear close. that said, if you have 3.73 or 4.10 gearing with a 31 inch tire you should be fine.

 

[Leeroy38]

How do you check which gearing you have?

 

[chefduane]

There is a metal tag that is underneath one of the bolts that holds the differential cover on. Or, check the axle code on the driver door build sticker. That should list the axle code. Just google that code here and various posts telling you the info should come up.

PS: I just went through the process of deciding whether to go with new 31's or the stock 235/75r/15's on my '98 SOHC 4x4. I ultimately decided to stick with the stock size and went with Michelin LTX M/S 2. Primarily a road tire. I decided at this point, with 210k on the clock and having to purchase an additional 31 for the spare, and probably not really going 'off road' just maybe a dirt or gravel road to a quail blind or camping, I just stay with a good set of stockers.
I have the 3.73 LSD with the tow package.

 

[corkey]

Long term like the over 150,000 miles i put on my 99 XLS with 31's,,
Only issue was clearance right away, , but after that it was pretty good,, i put the Monroe shocks with the coil springs on them in the back and just leveled it a bit with the torsion bars,,,
the engine and trans combination was the 4.0 ohv, with the 5r55e automatic,,,

it was a bit sluggish with the stock gears,(mine were stock 373), but it was livable,,
on the road it behaved well, and had the ability to go alot of places , and over parking stops or curbs with ease if needed,,
and winter snow was by no means an obstacle in any way,,

off road ,, i did a fair bit of that with it, some of it pretty harsh and lead a semi serious trail run with it too,,
only issue was on a few pretty steep hills i would have top go to 4 low to get up cause the rig seemed to power out every now and again, like it was givng all it had , and had no more,,,
but that is with the ohv engine being the one with the lowest power that was understandable,,,

in summation , it did a pretty damn good job actually and i would do it again too,,,

 

[Leeroy38]

Long term like the over 150,000 miles i put on my 99 XLS with 31's,,
Only issue was clearance right away, , but after that it was pretty good,, i put the Monroe shocks with the coil springs on them in the back and just leveled it a bit with the torsion bars,,,
the engine and trans combination was the 4.0 ohv, with the 5r55e automatic,,,

it was a bit sluggish with the stock gears,(mine were stock 373), but it was livable,,
on the road it behaved well, and had the ability to go alot of places , and over parking stops or curbs with ease if needed,,
and winter snow was by no means an obstacle in any way,,

off road ,, i did a fair bit of that with it, some of it pretty harsh and lead a semi serious trail run with it too,,
only issue was on a few pretty steep hills i would have top go to 4 low to get up cause the rig seemed to power out every now and again, like it was givng all it had , and had no more,,,
but that is with the ohv engine being the one with the lowest power that was understandable,,,

in summation , it did a pretty damn good job actually and i would do it again too,,,

Good to know. Can't wait to get the K02s on. I'm ready for the snow lol

 

[Turdle]

Tag on driver door jamb will give your axle code. compare with the axle code thread posted on this site. 31's with 373 gears is just fine. First thing you want to do is get rid of the AWD transfer case and install a selectable 4406 with low range. That thread is also on this site.

Good luck

Skip the headers and cam, unless you like the can of worms battle. Your stock cam is plenty for off throttle wheeling.

 

[beach]

I have 31s lifted (5.0 2wd), hardly a difference with the torque of the 5.0 and 3.73 gears and being rwd, just have custom exhaust and intake as well. Not sure how some don't rub on stock setup though, I still had to trim the front parts of the floor boards that go in the wheel well and can still rub at close to full lock and even more so if any flexing like reversing out a steep driveway etc. I have Pro Comp Alloy wheels which are pretty light, like over 10lbs a wheel lighter then steelies, doesn't seem like a lot but that unsprung weight makes a difference.

Hand calculating mileage though def took a nice hit, city is like 12 vs 16 before, and highway is around 17 vs 20-21 before. Not that I care, just didn't think it'd be that big of a difference with only 31s and especially using light alloy wheels. Few others I talked too saw about the same on 2wd 5.0s, so again not sure how some did this and saw no difference in mileage lol.... oh well. Kind of funny that my neighbors and a friends Raptor that is far heavier, with a much larger and powerful engine on 35s gets about what I do.... and would smoke me in a race haha

Really two problems only with the 5.0, cam swap is a nightmare b/c of no room, and trying to find and install headers on the 5.0 are both nightmares lol.