Offroad drivetrain durability as tire size increases

[Xtremluck]

Ahhh, thanks! I just re-read it. Didn’t see the stock option.

And i also saw that i was choosing the most expensive option with gusseted, reamed and hubbed spindles.

The steering setup alone is $1700-ish with just some work needed on your stock spindles.

Or u can buy theirs reamed out for $2000-ish

Seeing how a stock 4runner rack is about $800 bucks, I feel like $1600 is pretty fair for a tundra rack modified to fit our rigs. Benefit there is that you just have to keep tundra inner and outer tie rod ends as spares instead of 4runner parts. Pretty cool.

Yup I think its priced reasonably and is a great solution for just about anyone who wheels their 5th gen. Even with 33s your steering rack will eventually fail from enough off road use. Its such a common problem on this Prado 120 platform.

One thing we should check though is if those tie rod ends are indeed OEM stock Tundra. I think they may have been modified to fit our narrower track. So that would mean we would have to buy spares from Toyo Steering and we couldn't source them directly from dealers.

 

[Xtremluck]

Ahhh, thanks! I just re-read it. Didn’t see the stock option.

And i also saw that i was choosing the most expensive option with gusseted, reamed and hubbed spindles.

The steering setup alone is $1700-ish with just some work needed on your stock spindles.

Or u can buy theirs reamed out for $2000-ish

Seeing how a stock 4runner rack is about $800 bucks, I feel like $1600 is pretty fair for a tundra rack modified to fit our rigs. Benefit there is that you just have to keep tundra inner and outer tie rod ends as spares instead of 4runner parts. Pretty cool.

One more thing to mention, I just noticed that the Tundra rack Toyo-Steering is selling is using offset aluminum spacers instead of bushings for the main rack mounts. I think that is a really bad idea and will probably affect the life of that rack. You want some give in there for when your tires hit rocks.

 

[bigdaddy2021]

One more thing to mention, I just noticed that the Tundra rack Toyo-Steering is selling is using offset aluminum spacers instead of bushings for the main rack mounts. I think that is a really bad idea and will probably affect the life of that rack. You want some give in there for when your tires hit rocks.

yeah, thanks for the further details. I've definitely been mulling this option over in my head, including while my wife and I worked on some mods this weekend. (Marlin Crawler shifter boot install, iPAD mini mount for onXoffroad use, prep for C4 rear diff skid install, roof rack gear setup, etc) Took a minute to crawl under and take another peek @ our front-end setup.

My current thinking

CV's joints - I'm convinced that leaving stock CV's alone is the way and the truth for normal size tires up to 285/75-17 or maybe even small 35's. It's a known fuse. It's easy to "100% fix" on either side of the diff, with only one spare needed. And you can also easily cut-up a broken CV to provide hub and diff side "trail plugs" to allow you to 3-wheel-drive it off the trail without leaving the diff open or causing the hub to fall apart. For us, a gentle driving style, no aversion to pulling a winch-line and our dual cases, I really doubt we'll break anything. (I'm still carrying a complete CV and tools, just in case)

Stock steering rack/ITRE/OTRE - With 33's, 4runner owners are definitely UPPing the leverage we're placing on these parts, but again, it's a well-known and reletively easy trail repair, much like a CV joint that pops before the axle ears deform. For repairs, I am packing: both stock inner and outer TRE's and tools needed for repairs. At $50.00 a pop for brand new MOOG ITRE's I feel like I could have like 3-4 on-board for easy trail repairs without much worry. I know that MOOG's might not be up to OEM standards, but I just mic'd one right next to the $$$ OEM and specs/thread pitches are exactly the same for 1/3 the cost - great option at least for a trail spare, IMO.

For 35's and above: Not sure. You can prevent ITRE/OTRE failure with aftermarket parts, but what becomes the fuse? Do bigger tires solve more issues than they create? If you're running 40's - I think you're into a LC/Tundra rack - but then do you start blowing steering boxes? or spindle TRE mounts? Slippery slope

Planning to get some long-overdue dual case crawl testing done this coming weekend at a local OHV park. We'll be putting our rig through it's paces on some green and blue trails- with maybe a few black sections thrown in if we are feeling fiesty. - we'll be taking lots of video.

Our experience in Mt, Alaska, Utah and Moab, specifically is with hard pack, slick-rock, waterfalls, ledges and stable rockpiles, which is similar to terrain here in socal, but we'll definitely do a trail report after if we get into terrain we're not used to.

 

[bigdaddy2021]

Please continue to add input into this thread. Love to hear your experiences, even if it's just to add a vote to the poll.

Especially those folks who are running 35"+ sized tires since there's so little info in that area currently.

 

[honda250xtitan]

changed to skinny 34's. steering feels much lighter. now that i'm used to the look, i Kinda dont mind the 10.5 width

 

[jdm-v35]

changed to skinny 34's. steering feels much lighter. now that i'm used to the look, i Kinda dont mind the 10.5 width

How would you compare the skinny 34's vs 285s?

Curious on road manners, stability difference, acceleration and mpg difference.

For my next set I may go for 34x10.5 ko2's. currently on 285/70 e load ko2's.

 

[honda250xtitan]

How would you compare the skinny 34's vs 285s?

Curious on road manners, stability difference, acceleration and mpg difference.

For my next set I may go for 34x10.5 ko2's. currently on 285/70 e load ko2's.

going from e to c rating is a bit odd. wife dailies it so she noticed it alot more. she said it feels more touchy on the highway. Like itll wander more. mpg is unchanged as far as i know. crap

 

[jdm-v35]

going from e to c rating is a bit odd. wife dailies it so she noticed it alot more. she said it feels more touchy on the highway. Like itll wander more. mpg is unchanged as far as i know. crap

So would you say that it actually handles worse than wider tires? I was hoping skinny and taller tires would feel and handle better as well as be easier on drive components both on and offroad.

If it compromises handling I will keep running wider tires. I would hate to buy a set of skinnies and have them handle and feel bad while possibly not really gaining much durability in return and be stuck with them until its time for the next set.

 

[mrblah]

So would you say that it actually handles worse than wider tires? I was hoping skinny and taller tires would feel and handle better as well as be easier on drive components both on and offroad.

If it compromises handling I will keep running wider tires. I would hate to buy a set of skinnies and have them handle and feel bad while possibly not really gaining much durability in return and be stuck with them until its time for the next set.

I went from 285/70/17 ko2's which you probably can agree with me as having very uneventful driving characteristics (in a good way) to 285/75/17 geolander g003 MT, which resulted in more sensitive steering.

IMHO, i think its expected due to the taller side wall. Probably worse if the tire was fatter. It is not bad though. I only notice it when im DEAD tired, or when someone else is driving and I'm the passenger.

FYI, the 285/75/17 share the same footprint as the 285/70/17 size so driving characteristics will be similar. Fitment will be similar as well. Only thing i had to do was extend my front bumpstops and that was more of a optional thing than a necessity.

 

[jdm-v35]

I went from 285/70/17 ko2's which you probably can agree with me as having very uneventful driving characteristics (in a good way) to 285/75/17 geolander g003 MT, which resulted in more sensitive steering.

IMHO, i think its expected due to the taller side wall. Probably worse if the tire was fatter. It is not bad though. I only notice it when im DEAD tired, or when someone else is driving and I'm the passenger.

FYI, the 285/75/17 share the same footprint as the 285/70/17 size so driving characteristics will be similar. Fitment will be similar as well. Only thing i had to do was extend my front bumpstops and that was more of a optional thing than a necessity.

So with the taller sidewall do you just get more wandering? or does it actually feel more difficult to steer? I have extended front bumpstops and extended rear as well(metaltech long travel kit) so all I haven't done is BMC and pinch weld mod. I like the idea of it being unaffected by staying the same width but was considering 34x10.5 to possibly make it easier on steering components when doing the next tire change. the 3 different sizes being considered for the next set would be 285/70, 34x10.5 and 315/70. Trying to figure out the handling and wear effects between them that people have experienced.

I currently have the 285/70 which have been great. They are at 6/32nds with 45k on them but I do notice their winter handling has gone down since being new, though I now have 285/70 Hakkappelita LT3 studded tires for winter, during the transition to full winter the KO2's are still on.

 

[mrblah]

So with the taller sidewall do you just get more wandering? or does it actually feel more difficult to steer? I have extended front bumpstops and extended rear as well(metaltech long travel kit) so all I haven't done is BMC and pinch weld mod. I like the idea of it being unaffected by staying the same width but was considering 34x10.5 to possibly make it easier on steering components when doing the next tire change. the 3 different sizes being considered for the next set would be 285/70, 34x10.5 and 315/70. Trying to figure out the handling and wear effects between them that people have experienced.

I currently have the 285/70 which have been great. They are at 6/32nds with 45k on them but I do notice their winter handling has gone down since being new, though I now have 285/70 Hakkappelita LT3 studded tires for winter, during the transition to full winter the KO2's are still on.

More sensitive not more difficult. It wanders more so you have to pay more attention on the freeway. Around town there is no change.