Outer Limits 4x4 Board

hay guys im slowly building up my gu wagon, its the 2.8 turbo deisel, small and gutless but goes hard. im running 33 bfg muddies and all the drivetrain ratios are standard. im looking at getting reduction gears and im thinking at around 80-85% would be good. has anyone got any info for me on what brands i should look for? any help would be appreciated.

and yes i have done a search but couldnt find anything about the 2.8 with reduction gears, only the 4.2 and 3ltr. im pretty sure the 2.8s are running same gear box and transfer as the 4.2 so would 4.2 reduction gears work if they are the same?

cheers tom.

80-85% ig good if you rock climbing (crawling) there the ones for the job
but if you are going to do a lot of bog hole work than there to low in my opinion i would go around 60%

rogantriton wrote:im pretty sure the 2.8s are running same gear box as the 4.2.

Im pretty sure they arent.

yeh i do a fiar bit of rock driving, ok if they arent the same then who makes reduction gears for the 2.8 box? had a look at marks4x4 website but couldnt find any for the 2.8

rogantriton wrote:yeh i do a fiar bit of rock driving, ok if they arent the same then who makes reduction gears for the 2.8 box? had a look at marks4x4 website but couldnt find any for the 2.8

they run the same transfercase however different gearbox.

marks kit will fit fine into your gearbox, you would probably looking at the 83% set.

Don't go the full 84%... I did this and somewhat regret it...

It absolutely rocks for rock crawling but will require you to sit in high range to keep up with a convoy and not use all of your fuel over 300 meters.

I'd welcome you out for a run with me if you want to see how they perform before you decide, but yeah, be sure you want them before you blow the cash on them.

cheers for the help weeman and froon, so the 4.2 reduction gears will work in mine. i do a fair bit of rock driving so would something around 80% be better? maybe a bit lower be better/?

cheers tom.

i have 83% gears in my ute with 4.1 diff gears on 35's and find them great on rocks for slow work but you do have to keep going back to high range but i find that is a fare trade off. If you are doing a bit more touring style i would look at a lower % set

rogantriton wrote:cheers for the help weeman and froon, so the 4.2 reduction gears will work in mine. i do a fair bit of rock driving so would something around 80% be better?

cheers tom.

http://www.marks4wd.com/products/gearma ... -gears.htm

From Marks Adapters there is
85%
43%
25%

I'd go 43% if you do a lot of offroad touring.
If I was doing Comp crawlng then 85%


Interesting, that everyone is all of a sudden saying about havin to stop and change ranges.. I've been sayin that would piss me off no end for years, but everyone said it wasnt an issue. Now in 2008 it is.

bogged wrote:

rogantriton wrote:cheers for the help weeman and froon, so the 4.2 reduction gears will work in mine. i do a fair bit of rock driving so would something around 80% be better?

cheers tom.

http://www.marks4wd.com/products/gearma ... -gears.htm

From Marks Adapters there is
85%
43%
25%

I'd go 43% if you do a lot of offroad touring.
If I was doing Comp crawlng then 85%


Interesting, that everyone is all of a sudden saying about havin to stop and change ranges.. I've been sayin that would piss me off no end for years, but everyone said it wasnt an issue. Now in 2008 it is.

If it was in my wagon it would probably annoy the crap out of me but seen that is the tourer 43% would be a great option but in the ute with 85% on 37s etc i don't plan on doing any touring so it would be fine

turbo gu wrote:If it was in my wagon it would probably annoy the crap out of me but seen that is the tourer 43% would be a great option but in the ute with 85% on 37s etc i don't plan on doing any touring so it would be fine

one of the blokes in the club has a grenade, and 83's runnin 35 Procomps.
We got to Upper Jamieson Hut once, he was in low range, came past me doing about 5000rpm on flat ground, barely moving.. THAT would shit me no end! Everyone in the area was lookin, pointing and laughing!

bogged wrote:

turbo gu wrote:If it was in my wagon it would probably annoy the crap out of me but seen that is the tourer 43% would be a great option but in the ute with 85% on 37s etc i don't plan on doing any touring so it would be fine

one of the blokes in the club has a grenade, and 83's runnin 35 Procomps.
We got to Upper Jamieson Hut once, he was in low range, came past me doing about 5000rpm on flat ground, barely moving.. THAT would shit me no end! Everyone in the area was lookin, pointing and laughing!

In the ute 4500rpm 5th gear low range is around 40kmh.

Fuck that i don't really like revving my GU past 3 grand! Think a 43% set will be the go for me.

Rock Hopper do a 83% reduction for the 2.8, avail thru BBM.
They were on sale a while ago for $995.
I have the 83's with 35's and some times ( depending on what you are doing) you will find that even those arn't low enough

yeh 83 will be low enough for me, just need that little bit extra when doing rock crawling. that that will definatley be the go. will contanct bbm when i got the money, cheers. tom

rogantriton wrote:yeh 83 will be low enough for me, just need that little bit extra when doing rock crawling. that that will definatley be the go. will contanct bbm when i got the money, cheers. tom

83 is the lowest you can get.
24 is 'just a little bit more'...

ok now i am confused. ok the sort of wheeling i do is mostly glasshouse mountians driving with a few of the guys off here wants 33s, lux89 ect. there are a fair few tracks that require a fair bit of rock crawling but there are also tracks that are just rutted out dirt tracks. would i be better off with the 24 or 83s?

rogantriton wrote:ok now i am confused.

This shows the ratios.
http://www.marks4wd.com/products/gearma ... -gears.htm

From Marks Adapters there is
85% The lowest - LOTS of RPM barely moving.
43% In the middle - My idea of a good compremise.
25% The highest - Not that differnet to stock, 'little bit lower'.

I'd take a trip to a few clubs, and go for a run in a few cars to see for yourself.

I've been in a 4.5 GU with over 240kw that has 83's low 1st, barely moved at all.

ok im pretty sure ill got the 43% gears, seem to be the best setup for the wheeling that i do. now just gotta save up the $$.

cheers for all the help guys.

tom.

rogantriton wrote:ok im pretty sure ill got the 43% gears, seem to be the best setup for the wheeling that i do. now just gotta save up the $$.

cheers for all the help guys.

tom.

Best thing you can do is go for a spin with someone with the gears already in.Imo you won't be happy with the 43's......if you are doing the tracks like the power pole, little and big red then 83's are the go, even tracks like cruiser canyon.But as i found out on the weekend in carnage canyon i could have done with 183% gears
And yes, with the 83's you have higher revs and a very low speed, the best thing with this is that when you pick up the throttle for crawling you dont really pick up the speed,and in turn you are lifting the torque and limiting the times you will break traction.

Now back to the 43's / 83's debait..........take your time and select exactlly what you think you will need, because if you are like me and you fit them yourself, you will fast understand that it is a prick of a job and something you will only ever want to do once

I have 83% and will be changing to 43% in the ute, old 83% gears goin into girls wagon.

bogged wrote:

rogantriton wrote:ok now i am confused.

This shows the ratios.
http://www.marks4wd.com/products/gearma ... -gears.htm

From Marks Adapters there is
85% The lowest - LOTS of RPM barely moving.
43% In the middle - My idea of a good compremise.
25% The highest - Not that differnet to stock, 'little bit lower'.

I'd take a trip to a few clubs, and go for a run in a few cars to see for yourself.

I've been in a 4.5 GU with over 240kw that has 83's low 1st, barely moved at all.

And would have enough torque to smash rockwell diffs.

BEst bet would be goto the marks web site that has been posted and have a look at the final ratios. It is a pretty good table and will help you understand the 83%, 43% & 25% thing.

I did have a nice excel spread sheet that had all these ratios listed with how fast the car will go for each gear ratio in each gear, for every 1000rpm and up. But it got lost in one of my computer moves.

turps wrote: But it got lost in one of my computer moves.

well make it again

Don't go any lower than you need to. Unless all your driving is crawling or you have an engine that is happy over a big rev range you'll have to constantly stop and change low to high. My 6.5:1 (185%) zook gears are great for the slow stuff but I'd like something in between too. Even in 3-4th low it's still too slow on flat sections between climbs and means changing back to high at the top of every hill while the other cars in the group have to wait. So it's good and bad.

I've got a calculator you can have if you want Bruce. Not great but does the job. It's got suzuki ratios in it at the moment but wouldn't be hard to adapt. I've got nowhere to host it but PM me an email address and I'll email it.

Speeds per 1000rpm in Hi/Lo through each gear displayed on a table.

Looks like this.

zookimal wrote:Don't go any lower than you need to. Unless all your driving is crawling or you have an engine that is happy over a big rev range you'll have to constantly stop and change low to high. My 6.5:1 (185%) zook gears are great for the slow stuff but I'd like something in between too. Even in 3-4th low it's still too slow on flat sections between climbs and means changing back to high at the top of every hill while the other cars in the group have to wait. So it's good and bad.

I've got a calculator you can have if you want Bruce. Not great but does the job. It's got suzuki ratios in it at the moment but wouldn't be hard to adapt. I've got nowhere to host it but PM me an email address and I'll email it.

Speeds per 1000rpm in Hi/Lo through each gear displayed on a table.

Looks like this.

Can you help out please where you found that spreadsheet, I could not find in the Marks Adaptors Site

Sorry I did not read your post properly, it's yours.

bogged wrote:

turps wrote: But it got lost in one of my computer moves.

well make it again

I stole it off some one else. Could have been one of the Rowlandsons.

I went the 83% gears in my 2,8 to spin 35" tyres
and it was tops

If you find it too slow just use 5th beer
or 2H

But for rock work go the 83% hands down

I got the 24%

No offroad yet just tried them out. My set up is a diesel 4.2 with 4.3s with 35s.

Gear changes were done at 2000rpms

1st is good for 0 klm/h
2nd is good for 5 klm/h
3rd is good for 15 klm/h
4th is good for 30 klm/h


My stock set up was

4th was good for 40klm/h at 2000rpms