[fergy]

I want gearing but I want to drive on the beach still
I don't mind it reving high at a dollar ten on the hway
I don't think that I need to go all that fast on the sand
What is everyone that still drives sand running
Will 6.5s be to low ?
I still want to drive ledges and steps
Can I use low 4 in fifth gear
People say that some gearing is to low for sand
You can stick your mudding though don't like it
Help

[Zook_Fan]

What tyre size and diff ratio?

[fergy]

31" tires
std sj70 gearing 3.7 I think

[pezz]

I did robe to beachport on 30s with 3.9 diff and 4.9 case, was fine.

Personally id put 4.9s in it over 6.5s, then if you ever go bigger tyres just change your diff gears to suit..

[Zook_Fan]

pezz wrote:

I did robe to beachport on 30s with 3.9 diff and 4.9 case, was fine.

Personally id put 4.9s in it over 6.5s, then if you ever go bigger tyres just change your diff gears to suit..

This would be my advice too.

[jdk81]

Along with Zookfan, I would agree with Pezz.
If I was buying gears, I would get the 4.9s
I would also do diff gears.
The 3.9 diff gears are relatively cheap and easy, or possibly a set of 4.3 diff gears which would be my choice (can be found cheap, but require a professional install).

These combos are all pretty close to correct gearing in high range for 31" tyres +/- <2%
NT diff centres, and 1.58/4.16 transfer. low 1st gear of 59.25
4.9 low 1st gear of 66.69
5.14 low 1st gear of 69.96
6.4 low 1st gear of 87.11
6.5 low 1st gear of 88.47

Obviously you can mix and match more if you want the trouble of vit/gv gears etc but its a lot more work.

I previously had deep xfer gears, I found I rarely had a use for low 1st, and low 5th was super noisey.
So low range was only for really technical sections, and then I'd change into high.
Sometimes having to stop to change into low for a little bit, then back into high.
The constant stopping and changing really bugged me, as I found I didn't have a very useful spread of gears.

I personally find it easy to tolerate over gearing in high range.
Carrying a lot more rpm doesnt make that much difference to noise or economy, and holding 5th uphills is also easier, and drives better when loaded. 12% is acceptable, upwards of 20% tends to be a bit too much.
If its under geared or underpowered when in high range, you are into low range more often
If its over geared in high range, you can find you can use high range longer
If its over geared in low range, you are swapping into high range more.

There's no real right or wrong answer, its just looking for what seems to be acceptable to you.

[fergy]

cheers guys
most threads I had read previously people were all talking 6.5's
I was leaning towards the 4.9 gears
but also looking at the 5.14 because of the larger high range reduction
but I cannot find where to buy them

[alien]

I run 5.14 with 31s and high range is bang on perfect. I do however have a 1.6 which helps on hills.

Offroad with 5.14, sometimes i want 1 gear lower for low speed stuff (rocks). 5th gear in low range 5000rpm is about 50km/hr.

Depending on what type of sand you're driving on i think 5.14 is actually quite good. If you're regularly using 4th and 5th low then you'll have no issue just using 1st high, but if 1st high is too high then you've got 5 gears lower to work with... but it all depends on the average speeds the sand where you are allows you to go.

[fergy]

thinking 45kms probably fastest on sand that I need to go
no real large open sand areas that I drive
where do I get 5.14 gears?

[monley]

Lowrangeoffroad.com

[bally]

while on the gearing topic, what top speeds can be achieve in low range with a g13a 31s and 6.5s? also same setup but on 33s?

[Gwagensteve]

If you have any mechanical sympathy, not very fast. It's best to avoid exceeding peak torque in 4th gear whilst in low range. At a guess, I'd say that's <30km/h

Steve.

[bally]

hmmm no good. well keeping that in mind, will high range have enough to still pull through softer sand? mine gets used to prerun tracks for events up here so there is a mixture of soft sand, mud, rocks, winch walls etc etc etc. need a good balance of low range crawling and still have something up top.

[bally]

thinking 5.14's are going to be a better choice. still a decent drop in high range but not as deep in low... anyone able to confirm that 33's and 5.14s aren't a bastard to drive?

[fergy]

monley wrote:

Lowrangeoffroad.com

have looked there but cannot seem to find on the site
are they special order secret handshake sorta thing?

[fergy]

where do I find rocktoy transfer rings in perth?

[jdk81]

http://www.designfab.com.au/4wd-4x4/

Bent transfer arms are easier.

[fergy]

cheers jdk81
was just there
was hoping to find a distributor in perth
does benT have a web page or do I need to pm him on here
don't worry just remembered he is in ebay Right?

[Blkfxx]

BenT has a page on here in the business directory, also has items listed on eBay.

I can't find the 5.14s on LROR either, Maybe they aren't selling them anymore/for now

[monley]

bally wrote:

hmmm no good. well keeping that in mind, will high range have enough to still pull through softer sand? mine gets used to prerun tracks for events up here so there is a mixture of soft sand, mud, rocks, winch walls etc etc etc. need a good balance of low range crawling and still have something up top.

I run 6.5s, 3.9 diffs and 33s. I find this combo pretty good for sand. It can still pull 1st/2nd high with easy in soft sand

Edit: 5.14 gears https://www.calmini.com/detail.php?b=2& ... 3&p=830&n=

[fergy]

cheers monley
will check out ebay for bent

[bally]

monley wrote:

bally wrote:

hmmm no good. well keeping that in mind, will high range have enough to still pull through softer sand? mine gets used to prerun tracks for events up here so there is a mixture of soft sand, mud, rocks, winch walls etc etc etc. need a good balance of low range crawling and still have something up top.

I run 6.5s, 3.9 diffs and 33s. I find this combo pretty good for sand. It can still pull 1st/2nd high with easy in soft sand

Edit: 5.14 gears https://www.calmini.com/detail.php?b=2& ... 3&p=830&n=

and what would you say your top speed in low range is mate? just want to make sure im not going to be taking all day to drive everywhere in low range

cheers

[Gwagensteve]

Divide your current speed by 2.3 and there's your answer.

However, low range isn't for "speed" at all and as it takes about 3 seconds to swap between the two who cares? As its inadvisable to exceed peak torque in 4th gear in low range regardless of what gears you're running, you're never going more than about 40km/h in low range regardless of gears.

[jdk81]

There is no cheap and easy solution to obtaining the perfect/awesome spread of gears

As Steve said, it doesnt take long to swap between high-low. But it's trying to avoid that annoying region, where the sections are too slow for high, but way too easy for deep low gears, where constant changing is often required/desired.
This is where the autos shine, one of the extra things why autos are FOTM as an auto significantly reduces this problem, allowing high range to be used for a lot more things.


Simplified spread of sierra gears
1.3L - high 1st is equivalent of low 2nd
12%/1.0L - high 1st is equivalent of low 2nd
12%/4.16 - high 1st is equivalent of low 3rd
16%/4.9 - high 1st is equivalent of low 3rd/4th
18.3%/5.14 - high 1st is equivalent of low 3rd/4th
17%/6.4 - high 1st is equivalent of low 4th
20%/6.5 - high 1st is equivalent of low 4th

Deepness ratio (low range/high range)
2.268 = 1.611
12%/2.511 =1.59
12%/4.16 = 2.63
16%/4.9 = 3.01
18.3%/5.14 = 3.08
17%/6.4 = 3.88
20%/6.5 = 3.84

4.16, 4.9, 6.4 tend to lend themselves better to coupling with diff gears.
But if you have any case and change tyres and decide on diff gears later, it's not a huge deal.
Excessive high range reduction up to 12% is fairly easy to tolerate.

[fergy]

17%/6.4 = 3.88
20%/6.5 = 3.84

something looks odd here?

[jdk81]

That isn't a formula
It's just how I represented the more than stock high range reduction (in the same way that LROR list them and most people seem to use)
The 6.4 high range is 17% more reduction than stock sierra (1.649)
The 6.5 high range is 20% more reduction than stock sierra (1.692)

6.4/1.649 = 3.88
6.5/1.692 = 3.84

[bally]

And its that annoying section of gearing where low is to low that im hoping to avoid and without having a rig thats geared nearby i cant test these before buying. Majority of my driving is on hills, sand and as mentioned prerunning sections of new property for winch truck events. It wont be used for much rock crawling hence why im not fully sure the 6.5s will do whats needed. But i do want to run 32/33s and still have enough gearing to turn them easily in high range.

[fergy]

jdk

still not sure about that part of your chart
the 3.88 and 3.84 bit seems around the wrong way


Gear Set 4.16:1 Gears 4.9:1 Gears 5.14:1 Gears 6.4:1 Gears 6.5:1 Gears
Low Range Reduction 84% 115% 127% 181% 187%
High Range Reduction 12% 16% 18.3% 17% 20%

[Gwagensteve]

Jdk's figures are correct.

There is less spread between 6.5 1.69 than 6.4 1.65 - therefore the perceived gap between low and high range is greater with the 6.4's than the 6.5's, because high range is lower (higher revs for the same road speed) with the 6.5's even though the 6.5's have slightly more low range reduction.

Make sure the car is geared at least back to standard with your chosen tyre size, maybe a little deeper than standard. If high range comes out 0-10% deeper than stock, and 1st low is around 60:1-66:1 you'll be happy.

31's are going to be about 14% taller than standard at the most, so that's 4.9 or 5.14 gears will be ideal.

I believe the 5.14 gears are known to be noisy?

steve

[alien]

I just ran a proper test with my 5.14s ..

4th Low @ 3000rpm = 30km/hr
1st High @ 3000rpm = 30km/hr
2nd High @ 3000rpm = 40km/hr
3rd High @ 3000rpm = 50km/hr

So basically, if you want to go faster than say 35km/hr, use high range with 5.14 gearing.

And yes, 5.14 do have a whine to them!