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Reduction Gears

Posted: Wed Oct 10, 2007 6:09 pm
by jhsuzi
I will throw it out there for some input.

I am definately getting reduction gears, however I cannot decide between the Calmini 5.14:1 and the Trail Tough 4.9's.

I currently run 30's, but have a set of 32's to go on whenever i can make them fit. I have the standard wt 3.7 diff centres. I want better performance offroad, however i dont want to have to drive it full noise out on the road to get anywhere, as i dont mind tripping around. It is not going to be like a rock crawling buggy, but i want better control in the bush.

What are your thoughts?

Cheers :)

Posted: Wed Oct 10, 2007 6:11 pm
by Spike_Sierra
i got 4.9's on 30's but with 3.9 diffs.
revs great on highway and nice and low offroad. Should be good with the 32's as well.
current exchange rate and you will be laughing.

Posted: Wed Oct 10, 2007 6:13 pm
by nicbeer
either the 4.16 or 4.9s from lowrange offroad or calmini.

depending on if my transfer or box is noisy i am planning the same gears.


Spike, what revs u sit at 100 or 110?

Posted: Wed Oct 10, 2007 6:59 pm
by Spike_Sierra
not sure as i have a drover(no tacho, and jimny cant read normal tachos)
but at a guess around 3650. im sure steve could calculate it for me??? :)
i would suggest that 4.16 wouldnt be worth the money. i would go 4.9.

Posted: Wed Oct 10, 2007 8:03 pm
by 11_evl
just go the 4.9s, im sure u will have no problems selling the gears if they dont suit u perfectly

Posted: Wed Oct 10, 2007 9:49 pm
by Highway-Star
Spike_Sierra wrote:i got 4.9's on 30's but with 3.9 diffs.
revs great on highway and nice and low offroad. Should be good with the 32's as well.
current exchange rate and you will be laughing.
I would have thought that would rev too much with the 30's???


I'm looking at 4.16 gears, 30" tyres, and 3.7 diffs, should put basically back to stock ratio, with 30's really being 29.5" roughly.

I figure If I ever wanted 31" tyres, I'd either up the engine a bit or put in 3.9 diffs. but 3.9 diffs and the 4.9 transfer should give standard ratio for 32" exactly, which as Spike said should work well.

The Calmini 5.12's, would suit 31" tyres with 3.7 diffs, a tad high for 32", but works out same revs per metre as my setup (standard + 27") and that works fine.

All of this in high range of course.

Posted: Thu Oct 11, 2007 7:49 am
by Pep
I was gonna get Calmini 5.1:1, but came across a set of S4 6.5:1 allready in a case with strenghtening rings,
I originally throught the 6.5:1 would be to much, but i'm now very happy i got those gears.
I have 3.7 diffs on 30" atr and it sits on 3600rpm@100kph and i can hold 100kph, and it much easier on takeoff especially on hills.
And low range is just awesome, i can't believe how much it has changed the way the car behaves offroad i
dont have to brake on the downhill ect ect......
Basically wat i'm saying is i'm wrapped with the 6.5:1 :armsup: :armsup: and worth the consideration before getting 5.1:1

(Highway-Star if you wanna see how my drives before you get your gears just let me know)

Pep

Posted: Thu Oct 11, 2007 8:38 am
by Nev
Yeh I run 3.9 diffs, 30's and series 3 (6.1:1) and sits at about 3900rpm at 100kph. Bit revy but I usually sit at bout 3600rpm (bout 90kph) as its pretty comfortable there and I've got a bit left in the tank for overtaking and speeding up if need be.

Posted: Thu Oct 11, 2007 10:18 am
by Highway-Star
Just a question, are any of you people running the heavy reduction concerned about fuel efficiency? because the over-reving nature would produce some poor economy I reckon, the G13B is listed as reaching peak torque at 3500, which in theory should be an approximate happy spot, and it does this at roughly 100km/h in a completely standard WT in 5th gear. Need a six speed box :cool: .

I would go all out and buy the lower reduction gears, if high range would be right, I'm just not convinced it would be. My tyres will be 30", ay bigger would require work I'm not intested in doing.
Pep wrote: (Highway-Star if you wanna see how my drives before you get your gears just let me know)
Pep
Might get back to you on this, thanks for the offer Pep.

Posted: Thu Oct 11, 2007 10:30 am
by want33s
I have TG 6.5:1 transfer gears which are made for 33's. I only have 31's at the moment (with 3.7 diffs) and it's great..
It sits on about 3650 @ 100kays in 5th.
100 rpm less than it did with stock tyres and gears. :armsup:
I'll be fitting NT 3.9 centres when I put 33's on to try and keep it about the same as it is now.
High range is same as stock gears and tyres and low range is bloody awesome. 1st low is like a parkbrake.!! Don't hesitate, just get gears.. I promise you'll love it.

Posted: Thu Oct 11, 2007 10:52 am
by Pep
Highway-Star wrote:
Pep wrote: (Highway-Star if you wanna see how my drives before you get your gears just let me know)
Pep
Might get back to you on this, thanks for the offer Pep.
PM sent with contact details ;)

Pep

Posted: Fri Oct 12, 2007 1:13 am
by zookimal
I sit at 3500 at 100kmh calculated with 6.5s, 3.7s and 31s and it's perfect. Approx 3% under standard gearing.

My fuel economy improved over my previously overdriven setup. Standard gears and 215R15s (28s) which was about 108% which brought 100kmh down to 3000rpm.

Posted: Fri Oct 12, 2007 6:16 pm
by jhsuzi
Thanks all for your input, at this stage i am thinking of going the 5.14's, I reckon they should go pretty well.

Has anyone used the Calmini 5.14's?

Posted: Fri Oct 12, 2007 6:47 pm
by saffrett
any one know wat coily diffs are because i have calmini 4.16 and 31's and it does about 4.5k at 110 does that sound right

Posted: Fri Oct 12, 2007 8:07 pm
by NIK
i think 3.9s but Im not sure.
Nik

Posted: Sat Oct 13, 2007 5:43 pm
by Gwagensteve
coil sierra's run 4.09 diffs.

Steve.

Posted: Sat Oct 13, 2007 5:59 pm
by NIK
Damn wrong again :roll:
Nik

Posted: Sun Oct 14, 2007 8:05 pm
by NIK
Here is a gear calc of our club site to help you out http://www.sugarloaf4wd.com/ go to tech and click on calc
Nik

Posted: Tue Oct 16, 2007 5:53 pm
by NIK
Im trting to figure out gears vs revs and I need to know what is the high range of s1 gears. I know its 12% lower but what is the actual figure so I can plug it into the calculator.
Thanks Nik

Posted: Tue Oct 16, 2007 6:14 pm
by mick85
i really want to put 31/32 inch tyres on my zook but ill need to run reduction gears in order to push them around.

my transfer needs rebuilding so i think its the best time! DEEV8 has shown me some gearsets which might be of use... i wish to use the zook as i do now occasionally to tow the jet ski to the boatramp still..

puresuzuki.com
rocky-road.com
trailtough.com
http://www.lowrangeoffroad.com/

what is the best gearset to run to push 31/32inch tyres?? as these gears change the transfer does this mean i need to change my rear diff gears for 2wd around town?

cheers mick :)

Posted: Tue Oct 16, 2007 6:56 pm
by want33s
mick85 wrote:
what is the best gearset to run to push 31/32inch tyres?? as these gears change the transfer does this mean i need to change my rear diff gears for 2wd around town?

cheers mick :)
TG 6.5:1 is made for 32-33 inch tyre with stock diff ratios.
Remember that pushing a bigger tyre needs more power so you'll want it to rev a little bit harder.
I have 6.5:1 gears and love it. :armsup:
Sean at
www.lowrangeoffroad.com will look after you. :D

Posted: Tue Oct 16, 2007 7:18 pm
by nicbeer
Q for owners of reduction gears.

Anyone else here run a lot of beach/dunes/mud with 31s and gears? Minimal rock hopping and crawling. more higher speed stuff.

what gears have u got and how do they go for gear wise on obstacles.

Nic

Posted: Tue Oct 16, 2007 7:32 pm
by want33s
I used to have to slip the clutch and rev to 1500 at least to take off on level ground in 1st high with stock gears and 31's. I never used 5th!
Now, with 6.5:1's (20% lower in high range) I can let the cluch out at idle and take off. No slipping, no strain. I get to use 5th too! 3650 rpm at 100 in 5th.
Lowrange is whole new story. I can descend the steepest of hills without even thinking about needing to use the brakes.
On the beach, even in the dry stuff I don't use low range unless I'm towing my 7x5 trailer.
Just do it. :P Even if you don't like it, I'm sure you'd sell the built transfer for a profit. :D

Posted: Tue Oct 16, 2007 8:10 pm
by built4thrashing
for those that cant afford transfer gears why not swap in a 1ltr t/case and put 3.9 gears in their WT.

have to cheaper than gears i rekon.

Posted: Tue Oct 16, 2007 8:38 pm
by want33s
built4thrashing wrote:for those that cant afford transfer gears why not swap in a 1ltr t/case and put 3.9 gears in their WT.

have to cheaper than gears i rekon.
You might buy and fit 1lt case and nt 3.9 gears for half the cost but it won't be half as good as real reduction gears.

Posted: Tue Oct 16, 2007 8:56 pm
by mick85
want33s wrote:
mick85 wrote:
what is the best gearset to run to push 31/32inch tyres?? as these gears change the transfer does this mean i need to change my rear diff gears for 2wd around town?

cheers mick :)
TG 6.5:1 is made for 32-33 inch tyre with stock diff ratios.
Remember that pushing a bigger tyre needs more power so you'll want it to rev a little bit harder.
I have 6.5:1 gears and love it. :armsup:
Sean at
www.lowrangeoffroad.com will look after you. :D
TG means what sorry??? and how much are we looking at - as long as im getting good quality gear cost doesnt bother me and as stated i will be fitting them myself, no matter how steep the learning curve :)

Posted: Tue Oct 16, 2007 9:43 pm
by want33s
mick85 wrote:
TG means what sorry??? and how much are we looking at - as long as im getting good quality gear cost doesnt bother me and as stated i will be fitting them myself, no matter how steep the learning curve :)
'TG' means 'Trail-Gear' as sold by Lowrangeoffroad.
My gears and rebuild kit cost $812 (aussie) delivered.

Posted: Tue Oct 16, 2007 11:19 pm
by nicbeer
built4thrashing wrote:for those that cant afford transfer gears why not swap in a 1ltr t/case and put 3.9 gears in their WT.

have to cheaper than gears i rekon.
Yo.

Thats what i have now. just looking at options out there. 1ltr case is perfect for me now it seems but noisy bearings in it. doing a gear check to make sure there ok first.

i dont need massive low for rock hopping. so 4.16 or 4.9 is looking max for me.

Nic

Posted: Wed Oct 17, 2007 6:39 pm
by Gwagensteve
built4thrashing wrote:for those that cant afford transfer gears why not swap in a 1ltr t/case and put 3.9 gears in their WT.

have to cheaper than gears i rekon.
This is why -

Stock sierra crawl ratio - 30.52:1

Wt sierra with 1.0 diffs and a 1.0 transfer - 35.72:1

15% more crawl ratio, corrects a 30" tyre off road.

On road -

Stock sierra - 3300 rpm @ 100 with a full 26" tyre
Sierra with 1.0 transfer and 3.9 diffs - 3875 rpm @ 100 with the same size tyre, an increase of.... 15%

So, to run a 30" tyre on a sierra, you have to find two good condition nt diffs, swap your lockers into them, or get the gears swapped over into your housings, or find driveshafts and yokes.

A diff rebuild with a gear swap is around $150-250 an end. (no parts) and i don't believe it's a do it at home job unless you're pretty good with the spanners.
a good 1.0 transfer is around $400 from a wrecker. If you can find one.
A transfer rebuild kit, full, is about $250.

That's for 15% reduction remember.

People are paying AU$600-900 for US gearsets,landed, within a week. These often come in with most of a rebuild kit.

I just don't think anything else adds up. I think it's one of those areas where paying less really means paying more once everyhting is factored in.

If you NEVER drove hills, maybe the 1.0/3.9 combo would work, but it sure won't in victoria.

Steve.

Posted: Wed Oct 17, 2007 9:24 pm
by built4thrashing
i dont know who's been ripping you off for getting work done but ive never paid prices like that ever to get stuff done.


diffs are easy to pull and replace ya only need to get someone to set the backlash.