Outer Limits 4x4 Board

Wheres the best place to get diff bits for my WT sierra, im after shorter diff gearing. I think i only need the ring gear and pinion if it just bolts up to the standard diff center, i can set backlash etc myself.

PJ.zook wrote:Wheres the best place to get diff bits for my WT sierra, im after shorter diff gearing. I think i only need the ring gear and pinion if it just bolts up to the standard diff center, i can set backlash etc myself.

stock WT is 3:7
stock 1.3 NT is 3:9 and bolts up easily.
Vitara fronts can be modded to fit, ask an expert, but are very dear.

suziworld in Heidleberg or 4Play in Kylsyth are 2 places, but other diff gearing choices are most likely available in the states.
I think there is a lot of info on diff ratios in the Sierra bible.

christover

5.12 and 4.6 available in vitaras. need 2 x front diffs for sierra. as far as fitting > expert.

Nic

.....and also 4.30's from the GV 2.5 man. and XL-7 5spd auto (I have one front set available) and 4.875's from the 2.0 Vit and 2.5 GV autos.

What are you shooting for PJ?

Ususally, the cost difference between a pair of diff centres from a vitara and a rockhopper is not all that great.

Whilst changing the diff ratios can obviously correct tyre size onroad, off road it doesn't correct the inadequate sierra low range. Once the traction available increases with a bigger tyre, you will need more than just to be corrected for stock because the car will struggle to turn the tyres with the added traction.

A set of transfer gears will do both.

I would generally look at transfer gears first and follow up with diff ratios to tune it in.

Obviously igone this if you already have a RH

PS vitara ring gears have a larger ID than sierra so a sleeve or similar is required to stop the cross shafts falling out of the diff and smashing the pinion.

Hmm everything so expensive. Does anyone do pay by the month for rockcrawler gears?

would be better to put the $20 aside each week and pay for them in one hit. that way ya wont be charged fees.

PJ.zook wrote:Hmm everything so expensive. Does anyone do pay by the month for rockcrawler gears?

As a disability pensioner, money is hard to come by.
So I ask up front whenever I want something.
Most people are happy to lay-by stuff, officially or unofficially, as they keep the bits until you finish paying. So no risk to them.
I pay off in instalments quite a lot of stuff at suziworld in Heidleberg.
He won't order anything in, or build anything until paid for, of course.
I dunno if he would deal with rockhoppers, but worth asking.
But don't get any smart attitudes, or he will double the price

christover

Hmm well im gonna have to arrange something, gearing is the only big 'bad thing' with my zook, everything else is minor, but it really really needs decent gearing. I cant even go slow, it has to be wide open throttle slamming over all the rocks cos otherwise it will stall.

PJ.zook wrote:Hmm well im gonna have to arrange something, gearing is the only big 'bad thing' with my zook, everything else is minor, but it really really needs decent gearing. I cant even go slow, it has to be wide open throttle slamming over all the rocks cos otherwise it will stall.

isnt that how your supposed to drive

How much tyre are you running?

The easiest to come by vitara gear is the 5.12.

This is a 40% reduction over your existing ratio.

I assume you are not running over a 31" tyre, so that's just under 20% bigger than stock.

With 31's, you would still be pulling about 4800-5000 at 100kph on the highway, which is pretty hard on the motor.

Off road, about 20% more gearing will not be enough to get up back in control - the real need with about a 31 is for almost double stock - 4.1 is ideal.

I think that any of the other ratios, you will get the road gearing you eant, but not the offroad gearing.

Just my opinion.

Steve.

Hmm all my zook does is getting to, going on, and getting back from offroading. Maybe gearing is the way to go, or a double transfer maybe

PJ,

IMHO Dual transfers are more trouble than they are worth. Really, the only way to make it work is with a complete vitara engine conversion, cut or otherwise modified vitara transfer and your sierra transfer. What you end up with is all manner of custom parts (all custom crossmembers, driveshafts, heaps of mounts, etcetcetc) and the gain is a 4.09 low range with both boxes in low. On road, you have no correction for bigger tyres (although the vitara motor has a bit more grunt to push bigger tyres, its still not an ideal setup.)

Most dual transfer setups also include a diff ratio swap to offset bigger tyres, so the $$$$$ keep adding up.

On top of this, in a SWB the rear driveshaft length becomes pretty marginal.


The ideal way to go might be to keep your ear to the ground for a second hand series 1 rockhopper for sale.

PS you still haven't told us you tyre size or planned size. This will help us to give you more useful gearing information.

Steve.

I will state before my opinion on this matter, I do not wish for this thread to become disoriented fom its origional path of helping PJ out with his question(s) in relation to rockhopper gears vs. dual tfc's, another thread for another time.

Pj, if you want get up and go, more control in your offroad manouvers, etc- go the 'hoppers'. If you want good on road and off road acceleration and that reassuring feeling of plenty of torque up your sleeve feel to your zook, ratio change to 4.6 would be the way. If you're running 32's or taller tyres and the workers in your hampster control room are suffering from new Industrial Relation Reforms, (abused 1L or 1.3 carby motor) perhaps consider 5.11 centers- even though you'll grab higher revs on the freeway, you said you only take it to and from wheeling outtings- so you are really minimising the long term engine wear conseqences.

In my current setup, I'm running 33's, 5.11 centers, dual tfc's behind 1.6L gear box and a 1.6L mpfi vitara rubber band. My on road revs in 2wd high/high are 3,800 rpm @ 100kmph- not too bad really and pulls like a freight train. Off road, you get the best of 3 worlds, normal high range, 1.3 low or 1.6 low, or both together and more torque than oprah...
In the offroad sense of the world, you get the benefit of having enough torque to spin 33's without a problem in std low (1.6 or 1.3) and then in low/low get the controlled accent or decent on tracks that you would've been stressing about with a standard setup. Yes, it costs more, however, it gives you versatility offroad. Not to take away form the fella's that have 'hoppers- because they are a good product and suit some people and by no means am I going to enter the arguement that my setup is better than anyone elses- simply, it suits me, but it may not suit others.

End of the day PJ, do what suits your driving style and makes your on/offroad experience better mate. You're gonna get varying opinions from different blokes on this forum, none is 'gospel', it's just what works for us.

Thanks for all the opinions. Lots to think about.
My tyres at the moment are 30" mud terrains, i prob wont go higher than 31" maybe just maybe 33" if i find some cheap.