My gearbox had recently started crunching on 1st-2nd and occasionally 2nd-3rd gear changes.

The Obviouse thought's went through my mind about worn synchro's and large expense to remove the gearbox and repair.

However, as the car has know covered 62,000miles I decided to change the gearbox oil in line with the Subaru Service schedule.

So went and bought 4 litres of Castol syntrax from Halfords at a cost of £9.95 per litre.

40mins later, gearbox oil changed, and wow what a difference it's made. The box is now alot smoother throughout and has yet (3-weeks down the line, and including a trip to Trax) the gearbox has not crunched once.

Do I reccomend it....you bet.
That's the best £40 I've ever spent on a car and has potentially saved paying a rather large sum to have the gearbox repaired (I doubt any garage would of tried this before taking the box out and charging me for a rebuild).

Do it it could save you a small fortune too.

[This message has been edited by Scott.T (edited 07 September 2001).]

 

Did you need all 4 litres?

How did you manage pouring the oil down the filler tube?

 

According to the 'Capacities' section of my owners manual 4 litres is required. And yes I did get all 4 in and the dip-stick read spot-on (It's an MY94, not sure if later models are 3.5 litre).

I poured it down the dip-stick hole by attatching a 12inch length of rubber pipe to the end of the 1 litre oil bottle's pipe.

Made sure the gearoil was nice and hot before I drained it out, and as mentioned before it only took about 40mins.

 

A hint for filling gear oil . Warm the container(s) for a few hours in front of a radiator and it leaves it a lot thinner and easier poured in .

PS loosen the cap before warming to avoid an explosion .

 

I had a crunching synchro on 3rd gear on my last scooby. The dealer did change the gearbox oil but it made no difference at all.

They may, of course, have just told me they did or changed it for the same type, although they said it was different.

The garage ended up changing the synchro under warranty. This cured it but I was left with another problem in it's place- a diff whine!!! Had to change the car in the end. Doh!

F

 

I changed to "Syntrax" a while ago and it cured the crunching prob. I had from 4th to 5th at the higher speeds I posted a comment about this in driveline.
JohnD

 

best tip for thinning out the oil is to boil a kettle, pour the hot water in a bucket and pop the oil bottle in there for 10 minutes.

Hours in front of a radiator. LOL

 

BTTT, did you use 75W90 viscosity?

Can you use this for the rear diff as well?

Is this preferred to Redline Shockproof?

[Edited by john banks - 10/13/2002 10:00:41 PM]

 

what other oils, if any , are recommended. I.E. Millers, comma redline etc?

 

What about Motul Gear 300????

Tony

 

I use Motul Gear 300 in gearbox and diff. No crunching, car now has 82,000 on the clock.

 

I used to have Motul Gear 300 in my rear diff and I have to say that it gives more lock in the rear diff, I don't know why.
I am also curius about your opinions regarding the rear diff oils, I currently use Castrol 75/140 (produced mainly for Japanese diff acording to www.castrol.de).
JIM

 

I ended up buying 5 litres of Castrol Syntrax Universal 75W90 for the gearbox and rear diff. This meets the spec in the Subaru Owner's manual which lists the requirements for the rear diff and the gearbox the same. It needs all the help it can get

 

How come the YEAR gap between JohnF and JohnB??
JohnD

 

I dredged up an old thread

 

John.... are you not supposed to put a different oil in the rear diff to that of the gearbox. Scoobysport said to use a different oil and Motul told me not to use the gear 300 but a 90LS (whatever that is). It's due to the LSD at the rear..... however i thought that it being a viscous LSD it was just the oil around the inputs etc to the viscous unit that need the oil and as such you can use the same as the gearbox

Tony.

 

There is no plate LSD in the rear of a MY00 UK car.

Edited to add 'plate' !

[Edited by Andy.F - 10/15/2002 8:43:07 PM]

 

So Syntrax for the lot then Andy?

 

I used Syntrax for both, and see no reason why not to.
A local guy said that Prodrive recommend Shell LS ( i think that is what it was called ) but apparently it is hard to get, and bloody expensive.

 

Anything with LS on it indicates it's for a LSD.... i think.

It too thought like you Andy... that only the STi Rs and 22B had LSDs (plated) but i've been told that all turbos have some form of LSD. The 'lesser' models having viscous units. I've got a WRX and have been told to fit BOA90LS which is for LSDs by Scoobysport/TSL (their website has the info on this).

I've been through this debate before and some people use the same as the gearbox others use the LSD stuff..... im confused . So i don't know what to put in it.

Tony.

 

if your vehicle has a plated rear diff (LSD) then it is strongly recommended that you use "LS" oil otherwise problems will undoubtedly occur! if this is the case then obviously TWO DIFFERENT oil types will be required for your car.

however, if the car doesn't have an LSD then you can use a good quality gearbox oil all round.

personally we tend to use MILLERS synthetic oil throughout the drivetrain (although we have also used SILKOLENE and others) in the majority of the vehicles we service - our customer base includes shoppers thro' to full spec competition vehicles!!

alyn - as performance

[Edited by stockcar - 10/15/2002 8:49:39 AM]

 

Doesn't the confusion come from the rear viscous lsd (am I allowed to call it that Andy?) diff being a sealed unit, so the oil that goes in is for the driveshaft to diff joints rather than for the diff itself?

Seem to recall some hideously long post heatedly discussing this in the past

Richard

 

Yep, thats the one im thinking about Richard. All cars have a rear LSDs some are viscous units while others are plated. So i think if you haev the sealed viscous unit you can put gearbox oil in..... i think that was the conclusion. Not sure tho.

Tony.

 

Only plate type diffs, require a special oil, although some good quality oils do support LSD's anyway AFAIK.
A Viscous LSD, can be treated as any normal open diff as far as oil is concerned.

 

Ok.... so is everybody in agreement that you can put the same oil in the rear diff as the gearbox for at least UK and WRX cars?

Motul Gear 300 for me then .

Tony.