Fitting 42" tyres on an 80!

[plasticbadger]

Ok, a bit of an extreme 1st topic here, but I'm new to IH8MUD, not wheeling or rig building. I'm looking for some info before I think about buying an 80, so here goes!

What work is involved in fitting 42" tyres onto an 80, I've seen the Slee Offroad Short Bus and their SAS 100, so I know 40 to 42" tyres have been done. Is it just a case of proper lift and plenty of cutting, or is a wheelbase stretch needed (Short Bus isn't stretched, SAS 100 is at the front). With the amount of cutting are you into modifying pedals, or doors? What kind of lift height has been done with this size tyre, I'd rather cut the body than use much lift.

Since I'm asking (I'm sure I can find it by searching) how do the transfer cases hold up to extreme wheeling? I'd be using a UK spec HDJ80 4.2 diesel, with the fuel turned up etc., if that makes a difference.

Thanks, Plasticbadger

 

[dgangle]

here's some inspriational 4 ya....bwaaaaah haaa haaa

 

[plasticbadger]

Oh My God, my eyes, that's a terrible thing to post on my first topic.

Seriously, anybody got a suggestion that shouldn't be melted down for scrap. I've seen a few on here on 39"s, but I need BIGGER!

 

[dylanflyfishes]

I didn't know Lil Wayne is a Cruiser fan.

 

[finderscuba]

If you take a look at the arctic tundra trucks in this post, you'll see it is possible. I believe these actually run 44" tires.
https://forum.ih8mud.com/80-series-tech/218093-80-series-registry-9.html#post5160315

The red one seems to have had the rear axle shifted rearwards slightly. Obviously fender flares are much larger. I would say that the fenders were cut out slightly to accommodate those big tires. But not by much comparing to my truck.

 

[jlg32281]

What type of wheeling are you planning on doing? As you can see with the Artic trucks, they can fit 44", but they don't need much articulation as they use the tires to ride on top of snow and ice, not articulate over rocks and ledges. I think you could get 42" under there with a 6" suspension lift, another 2" of body lift, and some serious work with a sawzall. I think this setup would not only allow you to fit them, but also flex them. I'm no expert, so maybe someone else will chime in with some facts.

 

[Bikeman]

Look for dusty's thread in hardcore section to answer all your questions.

 

[plasticbadger]

Thanks guys.

It was a bit unfair of me not to give all the details, but I wanted to see the initial response (first post and all).

My plan is to replace the standard axles with Unimog 404 portal axles (narrowed, disc braked etc.). This will give me an effective 7" lift on standard suspension, but with only standard up travel.

I'll probably use the standard rear suspension setup, but with the links replaced with heim jointed adjustable links, keeping the standard springs. Up front I'll probably build a 3 link and use coil overs.

Wheeling wise, there's a couple of big Trophy Raid events in Europe the truck will be suitable for, such as Dresden-Breslau. It is likely also to be used as a support truck for my friend's Trophy Raid cars at Transylanvia Adventure Trophy and Croatia Trophy. Other than that just family wheeling on mud and rocks, going to the local store, that kind of thing. So it needs travel, handling, durability, the normal!!! Definately not like the Arctic Trucks set up!

 

[Walking Eagle]

What type of wheeling are you planning on doing? As you can see with the Artic trucks, they can fit 44", but they don't need much articulation as they use the tires to ride on top of snow and ice, not articulate over rocks and ledges.

that's a common missconception - I've seen photos of the artic trucks flexed out pretty darn good.

 

[bhmmapping]

IH8MUD.com - View Single Post - TiredIron's TLC build up
https://forum.ih8mud.com/80-series-tech/59452-tiredirons-tlc-build-up.html

 

[Tapage]

nice idea .. did you plan to cut fenders to make room for tires .. ? time ago was a project here with volvo portals in a 80 series .. I'm not sure about the tire size running at the time, but IIRC was around 38" or so ..

something like .. but I was loking for a white one ..

https://forum.ih8mud.com/vehicles-t...ustom-94-fzj-80-land-cruiser.html#post3588146

here is ..

https://forum.ih8mud.com/80-series-tech/59452-tiredirons-tlc-build-up.html

 

[bpassmore]

First things first, you need to spell TIRES correctly...

 

[Tools R Us]

This thread has some good fender cutting tech.
https://forum.ih8mud.com/80-series-tech/88594-cutting-fenders-paint-cm06.html

 

[PKP80]

Here is the Skinny on running 42's:

Not talking about lift, droop, or up-travel and only about tire diameter; You can't do 42's successfully on a stock axle setup (as far as I know). This is because a 42" tire will not fit in the rear fender well with out either major modification of the wheel well or moving the rear axle back a few inches.

I am not sure what the Icelandic cruisers do, but they are not articulating and needing very much travel if any. Dusty's 80 has D60 axles and he has moved the rear axle back to fit the 42's.

So first option move the axles back.

Second option is to take out the sawzall/grinder/plasma and start cutting. I am currently running 40's and have had to cut out a whole lot of fender, just shy of removing the rear wheel well (which will happen soon, b/c I want to increase my uptravel) just so I can have the truck flex and articulate without rubbing and getting stuck on sheet metal. Another issue I would have had with 42's is once you cut the wheel well you are right at the back seats and cutting at/into your rear doors.

Now, I have only touched on the fit of the tires' diameter as it pertains to the width of the wheel well. Turning our attention to Lift (suspension and body)several new factors come into play. How much up travel you want, what type of wheeling you do, how much more cutting are you willing to do.

I started at about a 10" lift about 8"suspension and 2" body, which was the WRONG way to go (the lower the better). So now I am doing what I can to lower the truck as much as possible. If you are willing to chop away at the truck and go into your wheel wells, you can do 40" tires with a 3 1/2" lift, Dusty does it with a 4". I am currently at about 6" of suspension and 2" of bodylift and I plan on coming down to about a 5 or 6" total lift (4" suspension and 2"body) when I get the time to work on the truck, but I want a good amount of up travel and all practical use of my truck has pretty much gone out the window. Touching on the front of the truck, you will also need to trim the fenders. I completely removed the inner shell of the fender, which gives you several additional inches of up-travel. If you're running a snorkel you don't really need that extra metal there, just patch up the few holes leading into the engine bay.

If you are dead set on running a big tires and want to drive it around and wheel it regularly, Slee 4" or 6", 40's, and some light trimming/cutting will work and if you want 42's, well you see the options before you as stated above. In all truth you don't really Need more than a 37" tire with these trucks, but then again all my practical sense has already checked out. Good Luck

 

[tblume]

Thanks guys.

It was a bit unfair of me not to give all the details, but I wanted to see the initial response (first post and all).

My plan is to replace the standard axles with Unimog 404 portal axles (narrowed, disc braked etc.). This will give me an effective 7" lift on standard suspension, but with only standard up travel.

I'll probably use the standard rear suspension setup, but with the links replaced with heim jointed adjustable links, keeping the standard springs. Up front I'll probably build a 3 link and use coil overs.

Wheeling wise, there's a couple of big Trophy Raid events in Europe the truck will be suitable for, such as Dresden-Breslau. It is likely also to be used as a support truck for my friend's Trophy Raid cars at Transylanvia Adventure Trophy and Croatia Trophy. Other than that just family wheeling on mud and rocks, going to the local store, that kind of thing. So it needs travel, handling, durability, the normal!!! Definately not like the Arctic Trucks set up!

curse your eyes! I want your wheeling life! http://www.youtube.com/watch?v=sbRwsgvQhS8&feature=player_embedded

keep us posted on your project- and welcome to 'MUD

 

[plasticbadger]

First things first, you need to spell TIRES correctly...

That's how we spell TYRES in English, it's not my fault you guys don't spell proper

curse your eyes! I want your wheeling life! YouTube - Official Reallye Breslau 2009 Intro

That's the one, no problems running a BIG truck in this event, there's classes for bikes, under 7,700lb wieght, 7,700lb to 16,500lb and 16,500lb plus. It's a tough event, many guys drop out after the first day as by that point you find yourself in the woods following some huge 8x8 russian thing on 54" tyres.

Here is the Skinny on running 42's:

Back to tech, as you can see my plan is to run portal axles which will give a 7" lift approx. I would hope from what I've seen so far to run no lift (body or suspension) and cut the body. Do you think if I run a 1" to 2" forward and rear stretch (i.e move the front axle forward 2" and the rear axle backwards 2") I'd be causing myself massive headaches? Then I could just tub out the wheel wells and cut the fenders for clearance.

I want to run a full body and street drive the thing as in 'support truck' mode it will have to be covering 150+ miles a day of paved and un-paved roads. To do that I've got to keep it low, but I don't mind chopping it about. I'd hope to run standard hieght suspension and standard up travel, then use the changes in links, joints and shocks to give increased drop travel. That way I can control roll and drop on the street with sway bars that can be dis-connected for off road use.

Thanks for your help.

Oh, quick edit to say the reason I'm looking at 42"s is that the Unimog axles come with a 7.68:1 ratio and are only rated to 50 mph. By fitting 42"s instead of the standard 38"s it gives me a usefull extra 5 mph before I risk overheating the portal boxes. I hope with a disc conversion and some cooling aids to be able to run it at 60 mph.

 

[SoCal FZJ80]

Putting 42" + Tires on an 80 (Icelandic Arctic Truck Style)

As for the Icelandic trucks in the pics above, You are correct in your assumption that the axle gets moved to the rear. Actually it is 12cm to be exact. The way they build the Snow trucks is by keeping the center of gravity low and working with the extra space in the quarter panels to fit the larger diameter tires. The reason they move the axle back is to avoid cutting into the rear fenders front arch which shares a common arch with back of the rear door. It is much easier to cut into the open quarter panel space. Arctic trucks were originally using a smaller suspension lift with a 50mm body spacer. Fortunately now you have a few different ready made suspension kits that can achieve 6" of lift without doing a body lift. The Icelandic trucks don't actually change the axles, but do change the gear ratio to compensate for the larger circumference tires. I am importing the parts from Iceland that they use to build these trucks. Below are pictures of the 44" kit flares at my shop which are the flares you see mounted on the red cruiser in the pictures. We are now building our shop 80 series to fit 46" tires. If all goes well, we will have the rig ready to debut at the All-Toyotafest in Long Beach in May. But one thing to remember is this gear is all application specific and excels for snow or sand use. If you are doing extreme rock crawling, this fiment may not suitable due to width and articulation limitations. The great thing for states with tire under fender laws is no matter if you are running tires as large as 44" or not- you can avoid violation tickets by keeping your rubber covered by fenders.

shadetreeaudio@yahoo.com SoCal Sound Shop (Ryan From SoCal sound shop) | MySpace

 

[Ebag333]

I would look at the Volvo portals instead of the Unimogs. IIRC they are the perfect width, and no problems running at 60 MPH.

Look at TiredIron's build for inspiration.

 

[Tapage]

which it's the top speed limit for Volvo portals .. ? ( if it have .. )

 

[Ebag333]

Faster than you'd go in a built cruiser.

(Or for some, faster than you should go.)



I don't know the exact top end speed. TiredIron said it was fine for freeway driving, and considering the amount of work he put into it I'd guess he'd know.