35's vs. 37's

[619TOY]

Well, I've been running my 35" Toyo's for almost a year and a half now. In that time I've read alot and wheeled alot and now I'm at yet another crossroad. Do I move up to 37's?

The consensus seems to be that making the move will increase my off road performance level. It will also bring my highway RPM's down thus (possibly) reducing the slight vibrations that I currently have above 55MPH.


Now for the downsides and my reservations:

1. I rub my 35's all the time. I think I have about 2 1/2" of bumpstop spacers and I still rub on the outer edges of the metal of the wheelwells.
How much more spacing to the bumpstops will be
necessary and how much travel/articulation will I lose?

2. My steering is pretty unhappy right now too

I have mounted an aux tranny cooler and plan on
plumbing it to the steering before it gets too hot
and hopefully mounting a fan to it as well. The ATF
doesn't last long currently before it burns/breaks down.
I change my fluid every few runs. Maybe hydro assist
is the answer?

This is not my DD by the traditional definition. I drive it a few miles a day to work and back. My number one priority is it's off road performance and remote camping access ability.

I have wheeled Moab and many local trails and have yet to see, first hand, any rig with 37's do anything better than I could with my 35's but but rarely wheel with rigs as capable or more so than mine so my experience is pretty limited. Generally, I have the most capable rig and therefore don't get the opportunity to try out the really tuff spots. There are times when I have not been able to overcome an obstacle and think to myself "if I only had 37's"

Another concern is that I have been so happy and impressed with my Toyo's that I would really like to run them in a 37 as well. The concern comes in the fact that they only make a 37 in a 13.5" tire. Will that thing even fit? like I said earlier, I currently rub the left outer wheelwell lip consatantly. I also rub the inner body on the right leading me to believe that 12.5" is the max width possible?.

I'd love to hear from those of you that have run both. I've read from some that 37's are a big improvement over 35's and some have said they wish they'd stuck with the 35's. I will be running the Rubicon this summer if that helps to solidify what my priorities are

EDIT: Heres a pic for your viewing enjoyment:

 

[Nay]

Well, I've been running my 35" Toyo's for almost a year and a half now. In that time I've read alot and wheeled alot and now I'm at yet another crossroad. Do I move up to 37's?

The consensus seems to be that making the move will increase my off road performance level. It will also bring my highway RPM's down thus (possibly) reducing the slight vibrations that I currently have above 55MPH.


Now for the downsides and my reservations:

1. I rub my 35's all the time. I think I have about 2 1/2" of bumpstop spacers and I still rub on the outer edges of the metal of the wheelwells.
How much more spacing to the bumpstops will be
necessary and how much travel/articulation will I lose?

2. My steering is pretty unhappy right now too

I have mounted an aux tranny cooler and plan on
plumbing it to the steering before it gets too hot
and hopefully mounting a fan to it as well. The ATF
doesn't last long currently before it burns/breaks down.
I change my fluid every few runs. Maybe hydro assist
is the answer?

This is not my DD by the traditional definition. I drive it a few miles a day to work and back. My number one priority is it's off road performance and remote camping access ability.

I have wheeled Moab and many local trails and have yet to see, first hand, any rig with 37's do anything better than I could with my 35's but but rarely wheel with rigs as capable or more so than mine so my experience is pretty limited. Generally, I have the most capable rig and therefore don't get the opportunity to try out the really tuff spots. There are times when I have not been able to overcome an obstacle and think to myself "if I only had 37's"

Another concern is that I have been so happy and impressed with my Toyo's that I would really like to run them in a 37 as well. The concern comes in the fact that they only make a 37 in a 13.5" tire. Will that thing even fit? like I said earlier, I currently rub the left outer wheelwell lip consatantly. I also rub the inner body on the right leading me to believe that 12.5" is the max width possible?.

I'd love to hear from those of you that have run both. I've read from some that 37's are a big improvement over 35's and some have said they wish they'd stuck with the 35's. I will be running the Rubicon this summer if that helps to solidify what my priorities are

EDIT: Heres a pic for your viewing enjoyment:

Your 35's are a 13.5" wide tire. I'd go 37's on a 6" lift without any question. I'm not sure I'd have to have the Toyo to deal with the wide tire, but then, I don't run Toyos and I won't

I really don't think it is worth taking an 80 to the next level, it's too big. I was out wheeling last weekend with a nicely modified Gen II Runner whose power steering pump kept going out. Ruined his whole day and he could barely get out of the 2wd part of the trail running those 37" Toyos. Reliability is such a huge part of the fun, it is easy to take for granted until you don't have it anymore, and then the spend is out of the box in a big way.

Having said that, if you think you won't break anything, the 80 can clearly use 37's in the big rocks. The day Interco comes out with a 36x12.5 trxus MT I will be awfully hard pressed to say no, but I hope they don't. Every now and then not making an obstacle is worth how good my rig is for every use I can come up with.

 

[619TOY]

Oh, I definately want them. Now I'm trying to fully justify them.

Hopefully the possibility of breaking something has been greatly reduced. I have both sets of R&P's heat & cryo'd with solid spacers front and rear and chromo axles front and rear. The next weak link shoud be my driveshafts?, which I have replacements for.

However, I feel as if my 6" lift has been reduced to 4-5" due to weight

 

[619TOY]

Wow, that was a pretty big edit

 

[Nay]

Oh, I definately want them. Now I'm trying to fully justify them.

Hopefully the possibility of breaking something has been greatly reduced. I have both sets of R&P's heat & cryo'd with solid spacers front and rear and chromo axles front and rear. The next weak link shoud be my driveshafts?, which I have replacements for.

However, I feel as if my 6" lift has been reduced to 4-5" due to weight

So what is the question ?

It's more than enough lift, even weight compressed. You can always tinker with shock travel to get the tires properly spaced. I would go with a 37x12.5, though. You don't need the Toyos for your lack of road use, and there are better offroad tires.

 

[cruzer971]

I ran the 37" MTR's on a 2" kit (with quite a bit of weight reduction). They didn't rub the outside lip of the fender. Just the inside wall. But the MTR's aren't as wide as the Toyo's.

 

[619TOY]

So what is the question ?

It's more than enough lift, even weight compressed. You can always tinker with shock travel to get the tires properly spaced. I would go with a 37x12.5, though. You don't need the Toyos for your lack of road use, and there are better offroad tires.

My worry is that somehow the uptravel that I lose will have a legitimate/noticable effect.

What tires do you think are better than the Toyo's since they've never failed to to grip like suction cups in my terrain? I'm open to just about anything but after having run BFG's for 20 years, the Toyo's are are on a higher plateau.

 

[619TOY]

I ran the 37" MTR's on a 2" kit (with quite a bit of weight reduction). They didn't rub the outside lip of the fender. Just the inside wall. But the MTR's aren't as wide as the Toyo's.

Yeah the 37' MTR is a pretty popular choice. I ran Moab with 80's running MTR's including one with 37's and he couldn't do anything that I couldn't (technically I was able to make it up one obstacle that he wasn't and he was able to make it up one that I wasn't all day). There were also a few 40's running 37 & larger MTR's and I clearly outperformed them with my 35's. I know that the MTR is a great tire but it has yet to prove itself the equal or superior to the Toyo in the terrain I frequent. Since I have had my 80, I have had the opportunity to experience alot more of the country and have learned how the hurdles placed on your rig can vary from one area to another.

 

[cruiserdan]

A full-trim 80 on 37's will be stressing the drivetrain (in my opinion) and you risk breakage.

Feel free to proceed and Do please keep my number handy....

 

[619TOY]

A full-trim 80 on 37's will be stressing the drivetrain (in my opinion) and you risk breakage.

Feel free to proceed and Do please keep my number handy....

Aw c'mon Dan, you should know that your number is on speed dial

I think that only Christo has more of my money than you

 

[cruiserdan]

Aw c'mon Dan, you should know that your number is on speed dial

I think that only Christo has more of my money than you

We both thank you.

 

[CodyRx7]

Just do what I do and rub the 39s until they turn into 37s or something...

 

[sdnative]

Steve, you never cease to amaze me.

Watching with interest.

 

[jasonmt]

I am running 37x12.5 Irok radials on 10" wide 15" rims on a Slee 6" lift and this is what it looked like with no bump stop spacers in the back, putting the 2" bump stop spacers in almost fixed the rubbing. I am going to try some 8" wheels this year to see if I can stay at 2" bs spacers and not have issues when the tyres are packed with mud.

If you can get the Toyo's on some 8-9" rims you might be able to get away with them? I have only seen the 37x13.5x18" mounted on a 18x8" rim and they did not seem any wider than the Irok's I have on mine.

This is DanKunz's rig with 37x12.5x16" Irok radials on stock 16" rims:

 

[Nay]

My worry is that somehow the uptravel that I lose will have a legitimate/noticable effect.

What tires do you think are better than the Toyo's since they've never failed to to grip like suction cups in my terrain? I'm open to just about anything but after having run BFG's for 20 years, the Toyo's are are on a higher plateau.

What shocks are you running? A 5" lift should easily allow you to space down the shock travel to run a 3" bumpstop with full travel on a 10" shock using a 50/50 travel ratio. You could trim a little if needed from there to preserve the flares.

The pic below are my trxus (35.0") fully stuffed with a 2" rear bumpstop drop. I have a 3" lift and have never rubbed on anything, and I have room to spare (and yes, Interco runs big). If I had another inch of bumpstop drop, shock (and therefore supsension) travel spaced down another inch, with another inch of lift, 37's would be a no brainer and I would have retained my preferred 50/50 travel setup. I'm not sure I couldn't run a smallish 37" MTR without any additional modification. A 36" would clearly fit with no mods.

Staying with the ~10" travel shock would keep you from starting to deal with coil travel issues (dropping the coil off the tower), and the 80's front isn't flexy enough to need to let the rear go wild with a 12" shock.

I think just about everything out there is better than the old BFG's. Let me rephrase to "as good as Toyos". I wheel with a ton of MTR users, and I think trxus MT is a better tire watching similar rigs on similar lines, especially in extremely low traction situations like snow wheeling, but it is not material. So trxus is an option, MTR is an option (and MTR's are smallish). The BFG MT KM2 (baby Krawler) would be an option.

The Toyo doesn't come in a 37x16, and you can't get 12.5. Staying with Toyo IMO really compromises your design. If I'm pushing tire width on a trail biased rig, I'm going after 37x14 IROKs. 37x12.5x16 IROK is off the shelf for you. No snow? IROK. Snow? 37x12.5x16 trxus MT (37.2" diameter). Perfect tire.

Anyway, you have plenty of lift to make this work (see project Rooby using 12" shock on 3-4" lift). I would only go up to 4.5"-5" to run 37's, but I'd also put my rig on a major diet to go with the bigger tires (mine is already on said diet ). But I think you have to be prepared to adjust shock travel to really optimize it, and possibly go high end on the shocks to account for dialing in only 4" or so of up travel with the weight of your rig.

I've love to have 37's, there is no question the level up it would take my rig, I just don't want to mess with it. If you want to mess with it, then IMO you have your answer

 

[Nay]

Wow, that was a pretty big edit

That is known as "The 3-Pint Edit"

I'm not posting to this thread anymore, it gets me wanting to tinker and go 37's. I don't need 37's, I don't need 37's, I don't need 37's...

Edit: one other point - bias ply tires are a good 20-30 lbs lighter than their radial counterparts. If you are serious about low road mileage, and offroad use, and remote back country use, then stepping up in tire size along with stepping up in the durability of the bias ply might be exactly what you need. You could go up in size and still lose 20 lbs per tire over your Toyos in terms of breakage risk, plus you get another 4-6 32nd's of tread depth.

It really seems like the principle advantage of the Toyo, which is roundness for a lot of highway use, is not what you need, but you are paying the price in a 13.5 wide tire in rubbing. Might be time to go the other way if you are going to a further trail bias...something to think about...

 

[LC80Ducati996]

Righ now I am torn between hankook mt's or trxus mts. The hankooks are narrow round and smooth running.. Trxus come in a 37x16x12.5 and work good in snow and ice in additiion to mud and rock.

If I go 37" I really want to look at things to trim and modify to get a bit more up travel. Tucking a tire up like that w.o spacers sure shows what is in the way

 

[Tools R Us]

... Tucking a tire up like that w.o spacers sure shows what is in the way

In my experience, the trick to tucking 37's is a narrow tire. I'm running Cooper STT's in 37x12.5-17 on Tundra 7.5" rims, with 1.25" spacers. They clear, but have 3" rear bump stop spacers, I think that 2" may work, haven't tried yet. They are killer on the trail and not near as bad as I would have thought in the highway.

 

[ats4x4dotcom]

I just moved my front axle forward 1/2 "
and we are making 3/8 shorter rear control arms, heim jointed one end, to stop the 37 hitting the rear of the rear fender at the moment.

I am running 17 x 8 rockcrawler rims with 37 x 12.5/17 Pro Comp tri ply muds.

I also have 1 5/8" bump stop spacers fitted front and rear, but running 12" stroke shocks front and rear as well, 29" rears and 27.5" fronts.

here is a pic showing some of the parts when developing the spacer/sway bar link kit early days

And this pic details the sway bar spacers, and brackets, round internal bump spacers which bolt onto the diff housing, and the chassis bump spacers we use for bigger tyres, with the longer shocks.

I am detailing the mods in my "PROJECT ROOBY" thread in the 80 section.

https://forum.ih8mud.com/80-series-tech/207630-project-rooby-80-all-rounder-build.html

The tyres just touch many places, but ....

if your tyres dont rub, it means you can run bigger ones

 

[landtank]

I just moved my front axle forward 1/2 "

Yes but that just puts the axle back in the stock location because you are compensating for the axle shift from how you corrected caster.

This drawing shows that near same shift in the axle's location. The gray drawing is the axle in the stock location. The green drawing is the axle after pressing in OME bushings. And the red drawing is after slotting the front hole by 14mm.

I think if you were to install those brackets on a truck that didn't shift the axle you would create problems.