Outer Limits 4x4 Board

G'day, I am toying with the idea of fitting Don Kyatt reduction gears to my 80 series petrol, hopefully this will give me a better final drive ratio as I run 35" tyres. Has any one had any experiance with these, are they really worth it? The small reduction they give should bring my final drive close to stock and they are cheaper than changing diff ratios.
Thanks for your input
Dave

grub_80 wrote:G'day, I am toying with the idea of fitting Don Kyatt reduction gears to my 80 series petrol, hopefully this will give me a better final drive ratio as I run 35" tyres. Has any one had any experiance with these, are they really worth it? The small reduction they give should bring my final drive close to stock and they are cheaper than changing diff ratios.
Thanks for your input
Dave

Hi Dave,

which engine does your 80 have? I'm not sure of the high range reduction of the don kyatt gears but the low range reduction is 3.55:1 (approx 43% lower than stock) so well worth it for the crawl ratio.

That said, if you have a factory turbo, or 1FZ-FE motor, it should cope well with the 35's and stock gearing. the engines that struggle the worse are the 3F(E) and the 1HZ, but the 1HZ can be boosted up to cope with the biggger wheels.

what's the asking price for the Don Kyatt gears? any info on the high range reduction (if any?)

cheers

Brian

slightly off topic, so how do you "boost up" a 1hz???
apart from a turbo

Id be interested in these too.Will have to price them as an overall reduction would be great for 35's

Hey dd, he mentioned that it was a petrol engine but agree a turbo diesel drives well without any reduction in gearbox/ diff gearing on 35's.

Id guess a petrol cruiser would be just as good.

timbocruise wrote:slightly off topic, so how do you "boost up" a 1hz???
apart from a turbo

a turbo or supercharger is the only way!

Kev80 wrote:Hey dd, he mentioned that it was a petrol engine but agree a turbo diesel drives well without any reduction in gearbox/ diff gearing on 35's.

Id guess a petrol cruiser would be just as good.

yeah so he does, that'll learn me to read the whole question. doesn't say if it's 1FZ-FE or 3F/3F-E though - and the 4 litre motors will struggle.

The information i have just got off them is that the ratios are 1.097 - 1 and 2.649 - 1 . They have them in stock in melbourne and the trade price of them is $1902. Diff gears sounding good !!

Surfection wrote:The information i have just got off them is that the ratios are 1.097 - 1 and 2.649 - 1 . They have them in stock in melbourne and the trade price of them is $1902. Diff gears sounding good !!

10% high range reduction - good. 8.5% reduction in low? not so good :( - get better results for less $ with 4.56 diff gears.

still cheaper than cruiser crawler from Marks' though.

Thanks guys for your responses, I have got the 1fz-fe and it drives quite well, just looking for better performance on road, hills etc.. and better down hill braking in low when out in the bush, I thought they may bring the ratios back close to standard. List price may be around $1900 but you can buy them for about $1400 with a little haggling. I see marks adapters wil have out a 25% reduction gear set at some stage. www.marks4wd.com/lc-80-100-extra-low-tc-gears.htm These could be worth a look if not to exe.
Changing diff ratios would be a bit more expensive at a guess, I haven't priced this yet, and I thought gear sets for the front weren't always available.

Dave

grub_80 wrote:Thanks guys for your responses, I have got the 1fz-fe and it drives quite well, just looking for better performance on road, hills etc.. and better down hill braking in low when out in the bush, I thought they may bring the ratios back close to standard. List price may be around $1900 but you can buy them for about $1400 with a little haggling. I see marks adapters wil have out a 25% reduction gear set at some stage. www.marks4wd.com/lc-80-100-extra-low-tc-gears.htm These could be worth a look if not to exe.
Changing diff ratios would be a bit more expensive at a guess, I haven't priced this yet, and I thought gear sets for the front weren't always available.

Dave

diff ratios can be done, drive-in, drive out for under $1800, and ratios down to 4.88 and 5.29 are available. (4.1 (std), 4.30, 4.56, 4.875, are all available from toyota for exorbitant prices).

the Marks gears look the goods but with no high-range reduction your on-road performance will obviously be exactly the same. They would have to be priced fairly aggressively too to make them worthwhile.

also "coming soon" from Marks can mean that they're a year or more away :(

just reading off the Marks site:

Marks 4WD Adaptors wrote:The kit consists of: Low range idler gear, Low range output gear and instructions.

is this is the case the kit only containts two gears and some paperwork - this SHOULD see the price of this kit well under $1000 - compare with the split transfer case gear sets which include EVERY gear in the case (input gear, idler gear with 2 gears on it, 2 output gears) for $1500ish.

hmmm... interesting....

One good point i picked up from lcool.....if high range is still 1/1....it shouldnt be noisy at speed.
Andrew

dow50r wrote:One good point i picked up from lcool.....if high range is still 1/1....it shouldnt be noisy at speed.
Andrew

according to the into on the Marks website, it only replaces the low wange gears, so high range is retained with all factory gears - which isn't possible in the split transfer due to the one piece idler - so yes if your transfer is quiet at speed now, it should be exaclty the same with the new gears. I am watching this with interest...

as for the Terrain Tamer/Don Kyatt gears, well who knows - have already been told two different low range ratios, both different to the Marks' ratio - and with a slight difference in high range ratio which I don't think an 80 needs - with 35's I still think the 1HD-FT is over-revving at highway speeds over 100km/h (and 150 - 160 is really revving the daylights outta it! )

Hey, I got a 1996 80 series 4.5 efi currently running 35" tyres and are very interested in gear reductions as well. I have a rough price 4.88 rations roughly $1000, and very keen to find out other alternatives as I plan on putting 37" tyres on and competing in various off-road events. Any advice would be greatly appreciated. Thanks Mick.

i have a set of Rockhopper gears fitted to my 4.5 pet auto 80, reduction is 44% and I am stoked with them. great ratio, no noise, and easy to fit. Call BBMotorsports for more info on (02) 9679-9744. Better still, come to the store and i will give you an in car demo.

Rick.

Thanks for great response these other gear sets sound good. I think that the Kyatt ones will probably be alot of money for very little benefit. I was unaware that rock hopper gears were available for 80 series but I will look into them and also the marks ones if they come out in the near future.

BBM Rick wrote:i have a set of Rockhopper gears fitted to my 4.5 pet auto 80, reduction is 44% and I am stoked with them. great ratio, no noise, and easy to fit. Call BBMotorsports for more info on (02) 9679-9744. Better still, come to the store and i will give you an in car demo.

Rick.

Do these gears only replace the low range gears like the Marks set? otherwise is there any change in high range ratio?

cheers

Brian

gotta love the trade price i just looked up the gear sets in thier price book and here is what i found

T/C HIGH GEARED RATIO KIT 0.912 - 2.415 $1,644.40
T/C LOW GEARED RATIO KIT 1.097 - 2.649 PART TIME 4WD $1,729.09
T/C LOW GEARED RATIO KIT 1.097 - 2.649 FULL TIME 4WD $1,490.24

Marks have now posted a price of $1195 on the web site for their gear set. http://www.marks4wd.com/lc-80-100-extra ... -gears.htm