RS Liberty Turbo Gearbox Problems

Morcs · Post by **Morcs** » Wed May 28, 2008 6:49 pm

Hi All
Got a major problem With my Brumbys Gearbox it kind of went bang in a not so pleasant way. Was driving home from my mates Place been (helping him with his Skyline). Had to Pull out into some traffic so gave it a bit of a boot in first then into 2nd rolled it on again then bang... no drive F@$# S$#$ etc after bang could only find 5th gear. Limped it back to mates place with only 5th gear also sounds/feels like a gear is half engaged as there was a grinding/grating noise commimg from gearbox. Going to have a look tomorrow.

Wondering wether it has bent a selecter or somthing like that

Just Wondering wether any body else has similar problems

I dont do hard launches burnouts etc . As i didnt want to have gearbox problems with it as they are reffered by my mates as a glass box.
When Treated with abuse etc

discopotato03 · Post by **discopotato03** » Wed May 28, 2008 7:42 pm

I gather that you are aware that RS Turbo's had different ratio diffs front and back and were corrected by the transfer drive gears in the back of the box ?

Anyway even so the box may have been given a hard time in it's last home and finally expired .
It sounds like box out time and often it's cheaper to replace it than to fix it because shrapnel has probably gone through everything damaging most of the gears and bearings .

A .

Morcs · Post by **Morcs** » Wed May 28, 2008 7:56 pm

Thats what i was thinking about its previous life. Where is a good place to source a gbox dont mind travling to sydney to grab one if i have have too. Debating wether to buy a motor gbox combo or source just the gbox. Any help Would be muchly appreciated.

Got to grab a new clutch as well as it all got a bit smokey trying limp it in top gear.

Morcs · Post by **Morcs** » Wed May 28, 2008 8:12 pm

Got a queston are the turbo/non turbo awd gearboxes different

AndrewT · Post by **AndrewT** » Thu May 29, 2008 11:18 am

Yeah quite different. Different gear ratios. The non turbo ones use a Push type clutch setup and most of the time the clutch is operated by a cable rather than hydraulics. The turbo ones use a Pull clutch setup. The bellhousing is quite different between the two due to this.

Post by **Alex** » Thu May 29, 2008 2:48 pm

brokended bokey woxey for you

RS and early GC8 rex's are notorious for blowing 2nd arent they?

alex

discopotato03 · Post by **discopotato03** » Fri May 30, 2008 8:16 am

What engine's in your Brumby Morks ?
Also what type of clutch actuation was put in it , cable or hydraulic .

If its an EJ engine and cable clutch then virtually any cable type box should fall in .
If you can hold out for a series 2 dual range one then that would get you close ratios 1-4 and the same taller 5th as the RS turbo box .

From what I've read the only difference between gen 1 RS-T boxes is the ratios and that screwy reduction ratio between the transfers (in the back of the box) . Clutch actuation was different (I think) .
For some reason Subaru used a 3.9 front diff and a 3.545 rear diff so to make up the difference they fitted 1.1 to 1 step down gearing down the back , ie 1.1 times 3.545 = 3.8995 . Virtually all other Subaru 4WD boxes have 1 to 1 transfer gears and the same ratio diffs front and rear .

Anyway I would only chase another RS box if I liked the wider ratios or possibly if that engine was an EJ turbo .
I think we can all read between the lines what condition an original RS turbo box is going to be in given that it lived in a sporty turbo car and a heavy one at that . No doubt 2nd 3rd etc owners bought these cars to "have a bit of fun" so who knows how they've been treated .
We all know early rex and RS boxes are a bit marginal strength wise so when they've been given purple hearts they're an unknown quantity .
A gearbox from an NA Lib sedan or wagon is more likely to have lived a civilised life so the chances of getting a crow are less but not totally unknown .
If you want to be 100% sure then the only way is to buy and strip another complete gearbox and replace any suspect components .

Cheers A .

Morcs · Post by **Morcs** » Sat May 31, 2008 4:01 pm

Year Mine is a turbo with cable acuation and it has a push style clutch using a rs turbo gearbox. Fulcrum arm for clutch has been moded to make it a push type. So we can use a l series cable.

The rear diff ratio is a 3.9 vlsd.
I have sourced a another gearbox that is matched for a 3.7 diff ratio
I was hoping to be able swap over the transfer case etc and 5th gear as mine has had the highest ratio gear fitted so it has a decant over drive.

Morcs · Post by **Morcs** » Sat May 31, 2008 4:17 pm

Just double checked It is a dual range jobby
So could i try to find a 3.7 ratio diff and swap the centres over so i have a vlsd still.
As standard brumby l sereis etc i think where 3.7s
If so it may get the lifted big tyre treatment

AndrewT · Post by **AndrewT** » Sat May 31, 2008 8:37 pm

Yeah that definitely aint an RS turbo gearbox then.
Otherwise it would have a turbo pull clutch and hydraulics to actuate it, and no low range.
Sounds like just an early dual range EJ gearbox probably from a GX Liberty wagon.

If it's a road car then the best thing to do is spend a little time installing the hydaulic clutch master cylinder and getting it to work with the pedal. Then you can take advantage of a proper turbo pull clutch.

Otherwise source another dual range box and keep the current setup.

Morcs · Post by **Morcs** » Sat May 31, 2008 9:05 pm

I think it is a custom clutch pressure plate because it is quiet a heavy push on the clutch pedal new cable didnt help that much. Like i said before it has got a turbo box that i broke,and the replacement i am going to use is the dual range one. I have never had an issue with clutch slip before using this arrangment so i will just replace the clutch centre after machining the surfaces of flywheel and pressure plate.
Like said before i dont give it a real hard launch.
It has been running up too about 21psi boost with a vf 23 turbo on special occasions.

discopotato03 · Post by **discopotato03** » Sun Jun 01, 2008 12:55 pm

I wouldn't convert the clutch actuation just to get "a decent turbo clutch" , if you know where you can get your type clutch built up to the same (turbo)or greater capacity in its std format . Also the diaphragm pivot points can be altered so that it gives the same clamping force for less pedal effort .

I go through Penrith Brake and Clutch , the old wizzard there knows more about custom clutches inc road/rally/race than anyone else my rally crowd can come up with and they've been churning dirt for a long long time .
If a manufacturer makes a turbo spec clutch this feller can emulate it using a standard component (not cubic dollar race stuff) , it usually doesn't cost a lot more than a std one so why not ?

Cheers A .

A word of worning , resist the idea of sintered bronze or "button" facings , they are competition items and a bitch to live with on the street . Been there done that won't be doing it again . Race clutches are for race only cars end of story ...

Cheers A .

Morcs · Post by **Morcs** » Mon Jun 02, 2008 9:06 am

I have removed the clutch and on closer inspection found that it is a 2300 pound forrester clutch.

Thanks

Yes i agree with the button clutchs my brother put one in his clubsnort was a nice car to drive now its only good when you are driving it hard. The thing sucks in the traffic.

AndrewT · Post by **AndrewT** » Mon Jun 02, 2008 1:27 pm

Beefed up push clutches are never as good as a turbo pull clutch.
The pull clutch setup is better by nature (probably why Subaru choose to use them in the turbo cars!).
Apparently as the revs increase the centrifugal forces actually help clamp the pressure plate harder, it's the opposite for push clutches.
Changing the angles of the pivot points does help but you still have more force than you are supposed to on components like the clutch fork and clutch cable etc.
But still, the push clutch setups do last a fair while, I havn't had any trouble with my beefed up setup in the wagon and it certainly is fairly tried and tested with the L series 5spd mob. If you have a push type gearbox bellhousing then it's still the best option.

discopotato03 · Post by **discopotato03** » Mon Jun 02, 2008 6:28 pm

Ah - no not really . There is a type of clutch diaphragm assembly that has a weighted system that increases load with revs but its a brain dead system because it's torque load not revs that make a clutch slip . If your engine developed mega torque at lowish revs the centrifugal system wouldn't achieve much would it ?

Pull clutch/push clutch - either system can be made to work .
Go talk to the mega buck 600 + Hp Skyline GTR brigade , GTR's have had both systems too and pallet loads of smashed transmissions (far bigger and stronger than ANYTHING Subaru) prove that both work .

A .

AndrewT · Post by **AndrewT** » Mon Jun 02, 2008 10:55 pm

The turbo gearboxes also have the correct gear ratios to suit the turbo motors. But given this is an offroader it's best to go for the dual range gearbox anyways.

Morcs · Post by **Morcs** » Tue Jun 03, 2008 5:43 pm

I had been toying with the idea of a lifted big tyre ej 20 supercharged brumby/l series for a while.

Wanted to keep this one as it was for a while its just happened that i had the dual ratio g box. I guess that it might just be a turboed lifted ej one instead.

What i was able to save from the dead gbox was a .738 5th gearset that had been replaced so it had highish ratio top gear. I will see if it needs it to be changed in the dual range box Once i get it back on the road. (Dont need to remove the gear box to change 5th)

My Biggest problem its my daily driver so i cant really have it off the road for long periods of time.
And i dont like Driving the mrs's Car

Morcs · Post by **Morcs** » Tue Jun 10, 2008 6:47 pm

Yehar the the mighty brumby lives again.

Thanks for information Contributed.

ITs a bit slow in top gear.
Debating whether to rebuild old box or not
Where would should i get gear sets etc.

BaronVonChickenPants · Post by **BaronVonChickenPants** » Tue Jun 10, 2008 7:11 pm

Glad to hear it's going again, what did the gearbox specs end up being?

I never got a chance to use it and the details were a bit vague when I bought it.

Jordan.

discopotato03 · Post by **discopotato03** » Wed Jun 11, 2008 10:34 am

I probably shouldn't ask but how do you change 5th gear pair without removing the box ?

The reason I ask is because my L AWD box has the short 0.87 5th gear and its painful compared to the std RX 0.78 .

Having looked through various ratios it seems that 0.87 , 0.825 , 0.78 , 0.738 can fit the AWD gearboxes . I think their native applicatios are as follows .

1) 0.87 Carbutetted L Series with 3.9 diff ratio .
2) 0.78 MPFI L Series with 3.9 or 3.7 diff ratio .
3) 0.825 90's Impreza WRX with 3.9 diff ratio .
4) 0.738 90's Impreza WRX with 4.44 diff ratio .

Also note that some 4.44 Impreza boxes had a ratio spread of ~ 3.1 - 0.738 so they've moved everything up gear ratio wise and dropprd the diff ratio from 3.9 to 4.44 .
The 3.9 Impreza ones spanned 3.545 - 0.825 in some cases .

Cheers A .