[suzukikid]

Hey all im thinkin of going a bigger tyre on my zook....

I have 32s at the moment.....

have 6.5 gearing front and rear lockers....will be getting chromos....

i will obviously have to more trimming and tub the rear out for the 36's....

will the standard drive line put up with 36s? the transfer is all braced and stuff....

have been offered either 34 or 36 swampers at a good price!

thinkin of just goin the 34s though....

cheers in advance!

[SuziBlu]

I cannot say with great authority, but as far as I understand it, the weak point is the axles; so, if you are going chromos, its pretty much your choice.

Im putting 35s on my build.

[SierraDan]

Go 34's. And more than just a trim.

[ajsr]

running 36's will require twice the work of 34's

[ZookFan]

Sent you a PM

[Joshyboy26]

36s
Go big or go home!

[Highway-Star]

suzukikid wrote:

Hey all im thinkin of going a bigger tyre on my zook....

I have 32s at the moment.....

have 6.5 gearing front and rear lockers....will be getting chromos....

i will obviously have to more trimming and tub the rear out for the 36's....

will the standard drive line put up with 36s? the transfer is all braced and stuff....

have been offered either 34 or 36 swampers at a good price!

thinkin of just goin the 34s though....

cheers in advance!

Drivetrain up to and including the transfer case will only really be affected by its own gearing and the engine your running. The more engine and the more gearing you add, the more chance of breakage. (This isn't 100% true, but I'd work with it as a fair assumption).

Diffs, axles, CV's etc are your primary concern when making reliable for bigger wheels. All these components are more likely to break with the addition of more tyre, more engine, and more gearing. Various forms of shock loading are also bad for them. Also note, that the lower a pair of gears, the weaker they will generally be compared to an otherwise similar pair of a higher ratio (ie, 5.12 diffs are weaker than 3.7, both in 7").


So when do Sierra diffs, axles, CV's become inadequate? I don't know... But I have been trying to get some idea of this for myself for a while. My vague conclusions for high reliability (with a 1.6 and a 4.1, 4.9, 5.1 transfer), based on allot of sketchy and dodgey calculations, experience with smaller tyres on this drivetrain, and reading on the interwebs is this:

1.3 Diff centre: I'd happily say the higher ratio diffs are good for a 33, maybe a little bigger. Low ratio C&P's usually from Vit front ends, I would be very hesitant to exceed 33" of tyre, particularly in the rear. When exceeding these limits I'd be looking at 8" Vitara rear centres, which from my limited pulling apart and looking, seem to be a far more robust centre (this might be unpopular, but I'm almost game to say they are a stronger centre than a Dudlux 8", though I haven't compared pinion shafts yet).

Rear shafts: As far as I am concerned 31" tyres are limit of these if you run a 1.6. Maybe a bit more life with a smaller engine (though I know a certain 1.3 auto Sierra that kills rear shafts like a marksmen at a chicken shoot). I would be looking at some sort of stronger rear shafts, and there are a few people around running floaters in the back. I like Hy-Tuf as a material for custom shafts over Chromo... and I reckon 26 spline Hy-Tuff floaters in the back would be at their limit with about a 35" ish tyre... If you want more, I reckon larger shafts are the go, which can be done with Vit centres, though I don't know what you would use for stubs.....

Front shafts: Stock 22 spline shafts and 1.3 CV's are at their limit on a 235/75-15 or a 30" IMO. The cheapish Chromo shafts and CV's from yankeeland are heaps stronger. Yet to see someone kill a CV joint itself (heard of one getting a bit loose...), but the shafts they come with seem to be breakable on a 31" tyres car (seen a few die now). That said the broken ones do seem to suffer a bit of abuse. I'd happily run the aftermarket shafts and CV's with 33's. I might take a gamble with a bit larger, but I'd be getting better quality shafts made first (hello Hy Tuf again), and then wondering how long the CV's themselves will last. I'm wondering how good some custom made CV's would be, as the double toughs seem quite poorly made...



I'm sure people will disagree though

[Gwagensteve]

I'm not going to argue with Highway-star at all there - except to say that with years and years of service, we haven't broken a doubletough CV or inner axle, across all the series of inner shafts. We are breaking hub bolts though.

Rear, full float axles look like they need to be Hytuff or 300M to be up to hard use and a 35"+tyre, and that's with a Vitara rear centre. I'll add a number of us are running solid spacers in the front R&P to prevent losing bearing preload and killing R&P's

If all that sounds like gobbledygook, (and a lot of coin) then you can see why those in the know are saying stay at 34", and pack some spare rear axles.

If you avoid all that and look at swapping to heavy axles ( hilux/patrol) you'll undo the advantage of the bigger tyres du to added width, bulk and weight.

On top of that, you basically can't fit a 36 between the firewall and the headlight.

As AJSR says, 36" is twice the work (and cost) of 34's to run.

You need to drive with and have a good look at cars running 35's to understand the compromises/costs. It's a massive step up from 32"

Steve.

[Highway-Star]

Gwagensteve wrote:

I'm not going to argue with Highway-star at all there - except to say that with years and years of service, we haven't broken a doubletough CV or inner axle, across all the series of inner shafts. We are breaking hub bolts though.

Just to expand. All broken front chromo shafts I am aware of broke on the short side shaft, where the spline goes into the diff. My Sierra's chromo is twisted here also, though (touch wood) hasn't "broken"... Steak Knife was the first person I know to break one... probably photos on here somewhere, but finding them would require sifting through one of his threads

Also seen a few sets of hub bolts die. Did a set myself, though mine were probably loose (other side was), which doesn't help

[suzukikid]

cheers guys! i was thinking tis would be the go!

ill go the 34s i think!

the 6.5s are real low on the 32's so i wont have to change gearing!

cheers boys!

[suzukikid]

ZookFan wrote:

Sent you a PM

I dont have a pm.....

[SierraDan]

Highway-Star wrote:

Steak Knife was the first person I know to break one.

[want33s]

suzukikid wrote:

ZookFan wrote:

Sent you a PM

I dont have a pm.....

Lucky you.

PM sent.

[DarkHorse]

suzukikid wrote:

ill go the 34s i think!

Dammit - was hoping you'd go 36s and I could get the 34s through you...

[Gwagensteve]

I'll add to this thread that as you are in Vic, you'll be dealing with the same traction that we are. Obviously we have limited rock driving and generally are traction limited. This is kinder on driveline than NSW and Queensland, which allows us to get away with a bit more tyre/a bit smaller axle. I'd say stock rear axles are pretty reliable on 33's in vic but pretty unreliable on 35's.

Also, keep you car as light as possible. Weight plays a huge part in breakage.

You'll 100% be wanting beadlocks once you step up in tyre size. Big tyres don't work on sierras unless you can get to around 5 psi. Budget these in to your buildup cost before you mount the big tyres up without beadlocks and find their performance disappointing. Take Gregc and my experience as an example, he was running his Krawlers at 8psi without beadlocks and hated them, beadlocked and at 4psi he's mad for them. my first trip out on Krawlers was at 6psi and I was unimpressed, but at 4PSI they rule.

Also consider s part of the "buildup" swapping to 1.0 rear bearing retainer plates or a rear disc conversion, that was to carry a spare rear axle you don't need to carry the whole drum backing plate/wheel cylinders etc and therefore don't need to bleed the brakes to swap a rear axle. Swapping a rear axle trackside is still big job (about 3 hours) because you'll have to get the broken bit of rear axle out of the diff centre, normally meaning the centre has to come apart, but not having to deal with the backing plates/brake work is a big plus.

If only someone made a full spool for a sierra/vitara then we wouldn't have the cross pins in the way and could knock the axle stub out with a broomstick.

I'll just say again - you need to drive some stuff alongside big tyred sierras and get a feel for how they perform and how we're holding them together.

Steve.

[got_bar_work]

Wat would u say the limit is for the sierra cromo cv in nsw with a heavy vit on it
33 be the limit or do u recon u could push it a bit more

[Gwagensteve]

What's the plan? A WT front axle in a vitara, or adapting sierra HD cv's to run in an IFS vitara?

Either way, I'd say it's not worth pursuing. A WT sierra front axle isn't strong enough (housing) and nowhere near wide enough for a vitara. and, if you want to stay IFS then go with the hilux/hagen mod. If you are going to build a custom housing to take longer inner axles and (lets say) a vitara rear centre, you're committing to a vitara rear centre and 26 spline axles in the rear, which aren't going to cut it for a big vitara.

It is/might be possible to go as large as 31 spline in the rear of a vitara, but the $$ in that is painful, and then the gear set might well become the weak link.

Steve.

[got_bar_work]

My strut riped out of my strut spacer on the way home on the weekend and this happened. No hight no steering lock and blowing cv is starting to get to me
I was thinking wt ends on a vit rear
Only running 31 most of the time but i would like to get something in a sticky bias ply for hard tracks and maybe comps
Only thing small i can find is creepy crawlers wich are around 33 or the swampers in 34
Any one know of any thing else in a 33

[Gwagensteve]

Unfortunately, there smallest "sticky" is 37"

Vitara rears run thinner wall tube than sierra fronts (!) and apparently bend easily when used in front from to a big sierra, let alone a Vitara. I Was surprised by this when I was told, but the vernier doesn't lie.

Look carefully at the cost of this path. Whilst a vitara rear axle is cheap, it won't work out wide enough unless you have it retubed (it's only just possible to get enough width for the long side of a sierra front out of a vitara rear.

You're going to be up for WT cv's, custom inner axles, a drag link, tie rod, locker, plus suspension work, then you're going to develop more traction (due to the travel) and run a bigger tyre. Whilst we're not breaking DT Cv's, we are on lighter cars... and we're full float rear. A 33 is going to break stock rear axles in a vitara, no question - so after all that work to the front, your weak link will be in the rear, and you can't get a 5.12 in any common stronger rear axle... and you're back to beating your head against a wall.

I think if you are serious about comp-type use and 33's (at least) It's time to step up to 60/70/80 series axles. You'll be chasing your tail trying to stay with suzuki stuff.

Steve.

[got_bar_work]

Thanks for the info steve
I do have a set of air locked 60 diffs sitting next to my shed
Only problem is they are so heavy

[Gwagensteve]

That's only a disadvantage depending on the comp. If it's crawling based, the weight (and to some extent the lost clearance) is less of a problem. If you're blasting greasy hills, the lost weight and HP will hurt.

Steve.

[got_bar_work]

The weight of the diffs would put it over its gvm

[suzukikid]

cheers gwagon! i got 2 spare rear axels here but didnt think of if it snapped on track....haha

[Gwagensteve]

got_bar_work wrote:

The weight of the diffs would put it over its gvm

I don't believe you. Remember you're removing a pair of diffs, arms brackets etc. I do know 'cruiser diffs are heavy, but remember that weight is lowering your COG, so dependent on the type of driving you do, it will be adding stability. The bigger problem re GVM is all the stuff in/on the car, because that's sprung weight which is stressing the chassis etc.


Suzukikid - whilst it is possible to drive some distance on a broken axle (and I've done it), it's pretty yucky on the insides of the diff. It can wreck the centre, preload adjusters etc, to say nothing of what it does to the bearings with chunks of hardened stuff floating around in there.

Steve.

[suzukikid]

Yep yep im pickin up what ya puttin down!haha

Just put down the deposit on the 34's.....for 34's it is!

cheers for the input guys!

[gregc]

34's??!!

Soft!

Didn't you read anything Steve wrote? Just because 36's are going to be double the work, that doesn't mean you shouldn't do it

[SierraDan]

[ajsr]

gregc wrote:

34's??!!

Soft!

Didn't you read anything Steve wrote? Just because 36's are going to be double the work, that doesn't mean you shouldn't do it

says the fairy who's only got 35's

[suzukikid]

gregc wrote:

34's??!!

Soft!

Didn't you read anything Steve wrote? Just because 36's are going to be double the work, that doesn't mean you shouldn't do it

Ah sorry bloke! i will give ya the blokes number so you can get em! maybe next time!

[fully sick coily]

36's = AWSOME!!!



DO IT!!!