Fitting 42" tyres on an 80! (1 Viewer)

[PKP80]

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.

I clearly missed the part about running mog axles, but it still doesn't change a lot of what I have said. just move the rear axle back a few inches and you'll be fine (thanks to the artic tech 12mm is definitely clear you of the 42" tire issue.

One thing to point out is that with MOG axles if they are anything like hummer axles (I think they are similar in style). Because you get all that ground clearance and natural lift. it means you diff sits much higher, which means that you can afford less uptravel on your axles. Ken Hanna (hannaquality) is running H1 axles and is limited to 6" up on the truck and you may want more. You can always cut out the back floor of the truck and raise it up but in the front you'll be hitting engine. I'd make sure that all your ride height and uptravel math works out nicely. I don't think you need the forward stretch since you don't mind cutting away and if I recall correctly, mog axles are wider than stock 80 which will help with turning radius clearance.

I would INsist on adding hydro assist to your setup as well and the proper steering and tranny cooling upgrades. 7.68gearing is INSANE (in a good way). with 40's and 5.29s all my gauges and response are just like stock. I'm not familiar with the axle heating issues that you're referring to. I'm sure some Royal Purple gear oil will help greatly with that. Post up some pics or start a build thread once you get started. let me know if I can help in any other way.

 

[lt1fire]

If you are running portals it actually won't be too difficult. I'd contact tiredironGRB.

Zero actual suspension mods and fit 40's easily with just the volvo portals fitted. He above anyone is the expert on that and should know exactly what else needs to be done for the extra 2" of tire.

 

[SoCal FZJ80]

44" Tires under an 80 series with no door cutting

I just wanted to give you guys a few more pics to see what is involved in putting 44" tires under the 80 series while still maintaining that "Came from Toyota" Look. Here is some pics of the red 80 posted above:

Inside the rear door there is no cutting required to the body to fit 44" when the axle is moved back 12cm:

Flare stops just short of the gas filler door, but you remove some of the quarter panel

Rear inner fender well:

Complete flare assembly installed on rear:

Rear of inner fender on front wheel well:

Front of inner fender on front wheel well(note minor bumper corner trimming to fit flare extension)

Rear outside view of fender flare installed:

Complete front flare installed:

As a Side note, I really liked TiredIronGRB's use of Volvo portal axles- if you are going to do an axle swap to something else- that seems very interesting. I like the height gains you get without touching the factory suspension geometry. Also MetalTech's tutorial on cutting out your fender arches is very informative. On my next build I am going to rely on my rebuilt factory E-locker axles as long as possible, since all the trucks in Iceland are using OEM drivetrain with the exception of a gear ratio change to the 5:29's - I figure don't fix what isn't broke. But if it eventually does, I will surely upgrade it. I will post build pics as the project goes along. ~R~

 

[Rambrush]

Very informative post, keeping center of gravity low with larger tires to fit.

 

[Nay]

TiredIron was using 2" OME coils (medium) on the portals, so it wasn't a complete stock suspension, although in the game of 40"+ tires close enough.

There really isn't anything important to the rear in the rear wells or to the front in the front wells, so clearly as is being shown you can make it work.

You'd want all that gearing for those tires if you are dealing with a lot of mud - 5.29's and 37's are barely adequate if you really need power from the stock drivetrain, and that's only 80 lb tires.

Having said that, your initial post on these few wheeling trips plus family mud and rock plus running errands sounds exactly like an 80 on 37's to me, or maybe skinny 38's.

I can't imagine relegating an 80 to 50 mph or so - at that point I think I'd wan't 54's.

 

[Rambrush]

There should be room to slip a over/under behind the xfer case on a 80 to allow it to run 80 all day long.

 

[plasticbadger]

Thanks for all the tech advice, from what I've seen so far my idea looks workable. To answer some of the questions and suggestions:

The reason I'm looking at Mog axles rather than Volvos primarily is cost (Mogs can be had here from $600, while Volvos can go for $5000 if you can find them), then it's because I came across some nice bits for them cheap! The Mog axle can be likened to a Dana 70 or 80 in strength, while the Volvos are more like a semi-float Dana 60 or 12 bolt. Volvos would be easier to fit and solve the speed problem, but I don't expect to be running a 42" tyred 80 series faster than 60mph for much of the tme anyway.

I've seen Metaltechs build before and thought about doing something similar, but built up a Land Rover Discovery on 80 series axles instead:

That ran 37" tyres without any issues, but other guys running in the comps I'm gonna be doing have run 37"s on 80 series axles and had plenty of breakage - front CVs and factory lockers mainly. That's why I'm looking at stronger axles and the Mog axles fit the bill. Here's my bother-in-law's Defender on Mogs and 44" russian tyres:

And here's my last build, again 37" tyres on 80 series axles, but I had to sell this to fund my soon-to-happen house move:

I hope to have the main bits together to start building by the summer, I'll keep you posted and do a build thread. The issue here is all the snow this winter has pushed 4x4 prices sky high, so I can't afford the base truck yet!

 

[Rambrush]

nice great looking rides

 

[lt1fire]

Nice looking rides. I love the lines of landys but can't deal with the weakness of some of the models.
Do you have a build thread on either of these??

Thanks for all the tech advice, from what I've seen so far my idea looks workable. To answer some of the questions and suggestions:

The reason I'm looking at Mog axles rather than Volvos primarily is cost (Mogs can be had here from $600, while Volvos can go for $5000 if you can find them), then it's because I came across some nice bits for them cheap! The Mog axle can be likened to a Dana 70 or 80 in strength, while the Volvos are more like a semi-float Dana 60 or 12 bolt. Volvos would be easier to fit and solve the speed problem, but I don't expect to be running a 42" tyred 80 series faster than 60mph for much of the tme anyway.

I've seen Metaltechs build before and thought about doing something similar, but built up a Land Rover Discovery on 80 series axles instead:

That ran 37" tyres without any issues, but other guys running in the comps I'm gonna be doing have run 37"s on 80 series axles and had plenty of breakage - front CVs and factory lockers mainly. That's why I'm looking at stronger axles and the Mog axles fit the bill. Here's my bother-in-law's Defender on Mogs and 44" russian tyres:

And here's my last build, again 37" tyres on 80 series axles, but I had to sell this to fund my soon-to-happen house move:

I hope to have the main bits together to start building by the summer, I'll keep you posted and do a build thread. The issue here is all the snow this winter has pushed 4x4 prices sky high, so I can't afford the base truck yet!

 

[plasticbadger]

No build thread on the Defender 110 I'm afraid, but here's my Pirate build thread on the Discovery and the Range Rover. I got pretty flamed on some poor bracket design, but I've learnt a lot since then!!

The Defender runs a standard diesel Landrover drive train on to the Mog 404 axles, which have been offset swapped on the front and converted to pinions. The suspension is standard layout, but roase jointed rear, custom radius arm front with stock springs and 10" travel remote resivour shocks. It's also got front and rear hydraulic winches, hydro assist, and a full internal/external cage. The wheels are stock 20" Mog wheels beadlocked with 12.50x20 Russian military tyres (actually 44" tall). My brother-in-law competed in the Romainian Translyvania Adventure Trophy last summer in it, but dropped out on the first day due to overheating. Video!