63% reduction v's 85% reduction.

Hi guys. I am looking at reduction gears for the GU. I run Toyo 315/75/16 with 4.6 diffs. I'm getting 2350 rpm in high at 100klm/h which I'm happy with. Low range is not ideal as i am finding I have to ride the clutch in some situations. I don't do the beach & i always shift to 4H or 2H on the tracks as soon as I don't need Low range. I am tossing up between the 63% (If ol mate has any sets left) & the 85% from Marks. I like doing the rocky stuff eg Spanish Steps for those that know the track & I had to slip the clutch a few times in certain spots.

I don't intend to give this rig as a hard time as I did the ol GQ, but still want to be able to do the harder tracks here & there. Doing some searches on the subject gets differing opinions as usual. What I want to see is some vids of GU's Or GQ 's running 63% reduction. Only one vid I can find & it's no use. I found a couple of good vids of a GU with 85%. 3lt & stock tyres so would be slightly slower than my set up I would imagine? I thought it looked good & would suit, but read a lot about those that don't like the 85% because they reckon it makes 1st useless & not much better for 2nd.

Need to get it happening soon & I'd rather not spend double replacing one or the other. So anyone got any decent vids of their or someones Patrol working the tracks with 63% reduction?

Cheers Jono.

Check you tube
Leck48 doing big red I think has 85%
Flex gq doing big red has 63%
Rob doing hilux hill is me with 63%

Quote:

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Originally Posted by 89gqpatrol4x4

Check you tube
Leck48 doing big red I think has 85%
Flex gq doing big red has 63%
Rob doing hilux hill is me with 63%

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Thanks. After watching that I think 85% might be the go for me cheers.

@Chubba ya nob someone wants to hear your opinion for a change! Get on it bro hahahahha

Quote:

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Originally Posted by 89gqpatrol4x4

Check you tube
Leck48 doing big red I think has 85%
Flex gq doing big red has 63%
Rob doing hilux hill is me with 63%

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Just read leck has 63%. I think the diference in what looks to be the ute ding things easier is the difference between petrol,Diesel & 4.2 & 2.8.

Quote:

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Originally Posted by TuffTD42

Just read leck has 63%. I think the diference in what looks to be the ute ding things easier is the difference between petrol,Diesel & 4.2 & 2.8.

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There is alot of rock in your area, if you dont mind crawlin over rocks in 1st low at slower than walking pace, if you like momentum over tractor dont get 85%
If you like wet slippery hillclimbs, dont get 85%
This is my 85% gears on a sandstone based track at 800-1000rpm, higher rpm crawling onto that rock. But you get the picture

https://youtu.be/CL0aNOQO71o

Hey Jono. My set up is different to yours as I run 285/75r16s and it's a 4.5l petrol auto. I do have a 63% reduction.
At 100kmh I'm only doing about 1800 rpms. Anyway for me the 63s are just what I want and i do a lot of the stuff you mentioned in your OP. I think the autos may get away with a set of 85s for what we do because of the higher ratio than the manuals. It would be very very low but I think you could live with it, but the 85s in a manual box IMHO would be far too low for a general all rounder set up. The 63s on the other hand would be gold. I don't have any vids of my exploits at hand sorry. Just my thoughts.

One point I will make is my vid I am going to fast! It was my first time up hilux hill and was the only vehicle there. So being a bit nervous and not wanting to get stuck I kept the boot in. Personally for a all rounder I don't think you can go past 63% . Having said that I have never driven a patrol
With 85%.

Thanks guys all great info. I would like the crawling ability of the 85's over the rocky stuff but also want a bit left for the slippery hills etc. Watching the vid with leck48 GU Ute I did think at 1st it seemed a bit quick for 85%, but also dose look to do the job pretty well. So for an all rounder 63% may be the way to go. Still chewing the fat on it, I'll keep watching the vids & hopefully can make a decision soon.

Well I crunched some numbers with the formula for working out the crawl ratio. I'll list 3.9, 4.11,4.375 & my 4.6's as it may help someone else who may stumble upon this thread. Firstly If I run 63% with my 4.6 diffs I'll end up just just higher than those running 85% on 4.11's.

Standard crawl ratio GU manual patrol 4.2TD is 33.576 with 3.9 diffs,35.384 with 4.11's,37.665 with 4.375 & 39.820 with 4.6's

24% reduction

Diff- Crawl Ratio

3.9- 41.620
4.11- 43.862
4.375- 46.690
4.625- 49.358

43% Reduction

3.9- 48.003
4.11- 50.599
4.375- 53.862
4.625- 56.939

63% Reduction

3.9- 54.695
4.11- 57.640
4.375- 61.357
4.625- 64.864

85% reduction

3.9- 62.120
4.11- 65.460
4.375- 69.681
4.625- 73.663