Okay I have been searching and it seems that the general concenus is that 37-39" tires are as big as one should go on built toy 8" axles. Most of the information I have seen was on toy axles under toys rigs. I didn't see much on toy axles under zuks running bigger tires. Again the size varied depending on wheeling terrain and style. I want to run 42" but wanted to see if anyone is successfully running a toy/42" combo on their zuk as swapping to 1 tons is not in the budget just yet.

I am currently running 37" mtrs. Zuk has a 1.6 16 valve connected to dual t-cases; 1.8 to 5.14 t-case. I am running 5.29 4cyl thirds with a detroit rear and welded front. (will be putting a 5.29 v-6 rear in soon.) and is sitting at a 100" WB. I am planning on upgrading to 30 spline longs and hubs, changing all of the studs to ARP's and heavily trussing the housing.

So anyone running toys and 39-42 on your zuk let me know how they are holding up. The tire would either be a 42" tsl, or 42" SXII.

well, I got 39.5 iroks on some chevy 1/2 tons and catch plenty of flak for it, so I doubt anyone'll bless the toyota+ 42" combo.

hardcore wheeling will stress the ring/pinion of a 'yota with 38-39s. I imagine I could break really cool parts with 42s.

:homer:

Robert Usnick here on the board (forgot his user name) is running his sammy buggy on 42" iroc stickies. he'd be the person to ask. not sure all the stuff he's broken but seems to be happy with those huge meats. although he did break the 6 stud TG knuckle studs.

here is details on his rig.
http://www.pirate4x4.com/koh09/drivers/robert_usnick.php

I wouldn't try it though. I'd rather stick to 37" tires and not worry that much.

I am hoping that the decreased weight and the lower horsepower of a zuk will be enough to offset the stess and strain that the 42 would put on the axles. I figure if I break my ring and pinions then I might drop to a 4.1 or 4.3 and go to a 6.5 case. Keeping my crawl ratio about the same but giving me more strength in the pinion.

My thinking is right in line with 4RngRick. I would like to run 42's but I might have to settle for 38.5 or 39.
2slo4u aren't you running 39.5 on your zuk? How have the axles held up so far?

I will look at that link I haven't seen that one. The main reason that I want to go up in size is I am constantly dragging my diffs and getting hung up on with the 37". I was initally looking at running 39.5 Iroks or 40" ltb's but found a great deal on a set of 42's. I might just have to shave the diffs and run the 39 to be safe because breaking parts isn't any fun.

If you don't have hydro steering then you weak link will be the r&p. I watched a r&p go with some 37's.

at least if you run 39.5's and break a chromo birf you won't have to lie to
Mr. long...:D

Ya i know this isnt a zuk but this is my experiance with big tires and toy diffs in something somewhat light weight



I ran 39.5 iroks for 2 seasons on toy diffs with minimal failure

leaf sprung buggy
4.3
th350
toy duals 23 spline back case
chromo output
longs
chromo hub gears
arp studs
6 shooters etc
stock 4.10s (blew 2 4.88s first and switched to 4.10 which i had great luck with

I pretty much had every upgrade for toy diffs except new housings


Then I switched to a dana 60 front and 42" stickies while keeping the ifs rear (trussed etc) and twisted the splines on some brand new chromo TG rears in 5 days in Moab. I figured it was only a matter of time to the r&p exploded

sold the rear diff and I am now building up a 1 ton rear diff so I dont have to drive it like its going to break

pretty much with all the money I had in the toy diffs to run the bigger tires if I could do it again I would of spent it on a 60/14 combo etc...

39.5s

395318

42's

395319

There ya go Bart! The "tons" are back in the mix, huh? With where you are now, maybe the tons are the way to go. But won't your diff clearance be close to what you have now? Especially with a 14bolt?

hey man with all the money you will spend on gears and such you could go get your self a mill surplus chev, we got two for $600 that has the 6.5dog i mean diesel with a d60/c14 bolt combo.:grinpimp: the rear axle by its self is generaly more than the cost of one of these trucks if you a buddy want and got two. the nice thing is you got all kinds of way heavy duty stuff. like a 1200 ccamp battery! dang can you say one battery welding! that thing is like three bills new too. you also get a trans and t-case you can sell to your ceby buddy's and that should off-set the cost of getting the truck to start with.:D so there ya go dude get you 42"ers and get-er done! oh and now you can sell your toy's to your small tired friends to so now you got some of your tire cost covered. bet you could almost come out ahead!:D

If you cut the lip off of the 14 bolt it does not catch bad at all. No worse than a toyota on 37 imo.

There ya go Bart! The "tons" are back in the mix, huh? With where you are now, maybe the tons are the way to go. But won't your diff clearance be close to what you have now? Especially with a 14bolt?

I am hoping that the decreased weight and the lower horsepower of a zuk will be enough to offset the stess and strain that the 42 would put on the axles. I figure if I break my ring and pinions then I might drop to a 4.1 or 4.3 and go to a 6.5 case. Keeping my crawl ratio about the same but giving me more strength in the pinion.

My thinking is right in line with 4RngRick. I would like to run 42's but I might have to settle for 38.5 or 39.
2slo4u aren't you running 39.5 on your zuk? How have the axles held up so far?

I will look at that link I haven't seen that one. The main reason that I want to go up in size is I am constantly dragging my diffs and getting hung up on with the 37". I was initally looking at running 39.5 Iroks or 40" ltb's but found a great deal on a set of 42's. I might just have to shave the diffs and run the 39 to be safe because breaking parts isn't any fun.

In regards to 'yota parts, our club has blown 4-5 thirds and snapped a couple of axles in the last 18months with 38-39" tires. Me personally, 7 months ago blew my front r/p and I wasn't beating on it. I don't think the other ones that failed were abused, just used real hard. :homer:

On the 42s, comes down to how you drive, throttle jocks will break parts faster for sure.

Okay I have been searching and it seems that the general concenus is that 37-39" tires are as big as one should go on built toy 8" axles. Most of the information I have seen was on toy axles under toys rigs. I didn't see much on toy axles under zuks running bigger tires. Again the size varied depending on wheeling terrain and style. I want to run 42" but wanted to see if anyone is successfully running a toy/42" combo on their zuk as swapping to 1 tons is not in the budget just yet.

I am currently running 37" mtrs. Zuk has a 1.6 16 valve connected to dual t-cases; 1.8 to 5.14 t-case. I am running 5.29 4cyl thirds with a detroit rear and welded front. (will be putting a 5.29 v-6 rear in soon.) and is sitting at a 100" WB. I am planning on upgrading to 30 spline longs and hubs, changing all of the studs to ARP's and heavily trussing the housing.

So anyone running toys and 39-42 on your zuk let me know how they are holding up. The tire would either be a 42" tsl, or 42" SXII.


Yes Toyota axles are Tuff but everything has it's place. We don't recommand any tires over 38 or 39.5. I have 42s not on my Toyota axles but only on my Dana 60 rig. 42s are way to much tire for Toyota running gear.

Yes Toyota axles are Tuff but everything has it's place. We don't recommand any tires over 38 or 39.5. I have 42s not on my Toyota axles but only on my Dana 60 rig. 42s are way to much tire for Toyota running gear.

God has spoken!

MOD please lock this thread down!

I'm about to try 39.5s on bobby longs, sixshooters and 5.29s with a detroit out front and welded rear. I wanted 37 Iroks .... but found a good deal on 39.5s local... why do I feel like I have gun to my head:shaking:

Rich

Um bang!

God has spoken!

MOD please lock this thread down!

I'm about to try 39.5s on bobby longs, sixshooters and 5.29s with a detroit out front and welded rear. I wanted 37 Iroks .... but found a good deal on 39.5s local... why do I feel like I have gun to my head:shaking:

Rich

ha! they didn't lock it. :homer:

I'm running the same set up right now except for a lockrite in the front. In regards to the third, make sure you're running a solid spacer on the pinion and the bearings are torqued. on a trail only rig, set the backlash on the tight side of the tolerance. I also had bobby cryro my last gear set.

At zuk hp (<100hp), I think were fairly safe. :grinpimp:

i am running 39.5 iroks on a 3000lb buggy.1.6 8 valve,dual yota cases with 4.7,30 spline longs tg6studs.the only problem that i have ran into is i broke a r/p,it locked up and snapped the rear output.its been replaced with a longfield chromo.ive been in many situations waiting for a birf to break but nothing yet.all around, they are pretty tough but i know they have their limits.

Well I think I am going to try and do it as I don't want to run 39"s or break my toys junk running 42"s all the time. So I am in the market for some built 60's if anyone knows where a set is with a decent price tag. The tire size I think that I will run is the 47" ltb's. Once I have everything or a majority of it I will start a build thread.

42's are way to much for toy's esp the R&P...