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gbox options for 4wd ej20G

Posted: Mon Oct 20, 2008 3:02 pm
by Alex
hey all,

just after afew opinions on what gearbox would best suit my needs.

Must be awd, preferably manual and dual range, its to go behind a 20G so it cant be a pissy little glass l-series box.

I was thinking maybe a manual forester box with dual range out of the later models with the 2.5L.

Also what mods am i looking at for fitting it to a l-series. Obviously inner cv cups, tailshaft mods, but what about the linkages? Will i need to use foz ones?

any other wikid ideas??

thanks in advance.

alex

Posted: Mon Oct 20, 2008 4:09 pm
by AndrewT
Change your driving habits. Purple L series with Ej20G on L series box has been going 6 years+ and not broken a single gear. AdamB has been running his car for quite a few months now and gearbox is fine.

Wanky has had both boxes last only a few weeks each! (correct?) :)


Other than that get a turbo AWD gearbox in there. All the low range ones aren't designed for turbo's either.

But to be reasonable I guess the best thing would really just be a Gen1 dual range AWD gearbox with an L series low range gear fitted. Should last better than an L series box and still be pretty affordable. Just need a little welding on the shifter linkages, change the crossmember abit and get the tailshaft shortened.

Posted: Mon Oct 20, 2008 4:35 pm
by L-Raiser
....If you are going to regularly drive hard offroad then the only really reliable setup would be an AUTO....the auto would help with rock crawling & sand driving too, like a consolation prize for not having duel range.

I thought about this option myself, EJ20G & auto, but I'd miss the gear changing challenges when offroading...

Posted: Mon Oct 20, 2008 4:43 pm
by vincentvega
built auto.

or

drive within the limits of the gearbox. Any dual range will die with enough hammering behind an EJ20T

Posted: Mon Oct 20, 2008 5:07 pm
by El_Freddo
Looks like you've been told mate!!!

Seriously though I think AndyT has hit the nail on the head with his comment about the turbo box - particularly if you drive the way I would with a turbo and a shrinking fat wallet...

My 2c

Bennie

Posted: Mon Oct 20, 2008 5:17 pm
by Subafury
just put another L one in there and take it easy. i know u dont wanna hear it but might have to slow down instead of testing the limits of the motor. thats the cheapest option. may not be easiest for ya tho :)

Posted: Mon Oct 20, 2008 7:06 pm
by adamb
another already alex! i do give mine a hammering offroad and its shown no signs of stopping, even with 250,000k's on it. The only thing i dont do is rev clutch dumps, which would in my opinion shatter an L gearbox straight away. i say just chuck another L one in as well. Definitely the best gearbox for offroading.

Adam

Posted: Mon Oct 20, 2008 7:12 pm
by D3V1L
yeh put another L series one in so after every trip u go out and break one u can put another on in, which so far seems to be every trip

Posted: Mon Oct 20, 2008 7:21 pm
by discopotato03
A little mechanical sympathy goes a long way unless you want to spend your days R & R ing gearboxes .

The main problem with ALL these gearboxes INCLUDING the six speed ones is the shaft centers - they aren't far enough apart which means the gears can't be made large enough in diameter to handle high torque loadings with sticky tyres and increasing car weight .
The situation is worse in a Liberty (particularly the wagons) because of the weight of the things .
The Rex rally people tried every trick known to gearbox engineers to make these gearboxes survive inc changing everything inside the std casings which for homologation reasons they had to keep - and still they handgrenade . Actually a lot of the problem is the split case design in aluminium because the casings can't adequately support the shafts under high torque loadings , torque reaction twists the cases and misalignment destroys the gears - provided the bearings don't fail first .

The sad truth is that Subaru has tried hard to stay with the same basic gearbox configuration because with std production cars it's adequate .
Also yes I agree with the 4WD dual range versions not being available behind turbo engines , the only exceptions here (Aust) were L RX turbo sedans (1070odd Kg's) and the std low range is not very low .

There is no real answer to this because the weaknesses are built in .
Actually beefed up auto boxes have a lot going for them and no doubt a manual shift kit could be fitted to a Subaru one .

A .

Posted: Mon Oct 20, 2008 11:46 pm
by Cam
how strong are the impreza d/r boxes? Some have the good reduction ratio and should be stronger than an L series?

Posted: Tue Oct 21, 2008 5:56 am
by Captain Obvious
early lib boxes have the same gear sets as l series any way, its generally the front diff that will blow in a l box from to many skids, i run a awd dual range behind my ej20t and they still dont last that long, and i dont drive like a race car driver! cheapest way would be to slow down and behave!!

Posted: Tue Oct 21, 2008 3:34 pm
by Alex
1. i dont want an auto.(too much work with wiring and gearsticks and stuff)

2. i dont drive it that hard. downshift into 2nd at moderate RPM and she goes bang. wtf. I havent been driving it hard with this box as i knew it was going to be weak. I wasnt even lanuching it at the drags ffs!

and this gearbox has done NO skids at all. The 29s are just stupid to spin. I take off easy, change gears easy and it still goes bang!

so im just after your opinions on a strong(ish) box that will suit my needs. I dont need a daddy talk. Ive learnt my lessons over time....TRUST ME!

opinions on d/r foz box?? has anyone done this before?

thanks heaps :)

alex

Posted: Tue Oct 21, 2008 3:45 pm
by El_Freddo
Keffa wrote: opinions on d/r foz box?? has anyone done this before?
PeeJay's done a Foz box with the L series low range. From memory the diff ratio was 4.1...

Do a search and you should find it without too much effort.

Cheers

Bennie

Posted: Tue Oct 21, 2008 5:07 pm
by discopotato03
Can you fill me in on "29's" as I'm not into Cruiser sized wheels .

Tall gearing and torquey engines is hard on gearboxes if their not designed for it . I suppose if you really want to run big diameter wheels something with short diffs would make life easier for the gearset .

Aside from some Rex's with 4.4 diffs (they have all the ratios moved up to suit the short diffs inc a much taller 5th ratio) what would have short diffs and the early ratio gearset ?
I would look into Forrester ratios or talk to Gareths gearbox specialist mate . He had either 4.1's or 4.4's and the lower non turbo L low range gears . He told me that you have to do a grinding operation on the crownwheel to make it clear the slightly larger diameter NA L low ratio gears because it was never a factory option as far as I can tell .

Looking like a built up gearbox I think starting with a low diff ratio AWD DR box .

A .

Posted: Thu Oct 23, 2008 9:05 pm
by PeeJay
El_Freddo wrote:PeeJay's done a Foz box with the L series low range. From memory the diff ratio was 4.1...
Yep, 4.111 and it's behind an EJ20G as well. 12 Months now 25,000kms and still going strong!

Posted: Thu Oct 23, 2008 9:48 pm
by SuBaRiNo
My opinion based on my research i have done lately... Turbo model EJ subies never seamed to have come with any dual rang box... largely because they seam to be weaker than the single range ones. Even turbo manual boxes when thrashed seam to be a common problem.

Auto boxes seam to be much stronger and hold up a lot better to punishment. I know you don't want to go an auto... not many people do but the reality is your going to loose things u are wanting to keep to make the box last.

Weather it be your low range ratio, dual range or being a manual you may need to make a choice. Posibly the last box u had was already about to pop if you indeed have been driving it nice like you say but knowing you it would have been punished a bit.

Dave