"Magic" Gearbox oil
 

Right, clutch is now working, thanks to all who helped :notworthy

Now when in years gone by I had a Golf GTi with crunchy gears, 1st into 2nd and 2nd to third (syncro on way out i guess) I changed the gearbox oil to a fully synthetic type and lo nice smooth quiet gear change. :norty:

What I would like to know is there an equivalent for the Scooby? These bleeding pricey gearbox oils (redline for example) are they only really aimed at competition / trackday boys? Would we streetfighters :) see / notice anything other than a lighter wallet?

Regards,

Mike

Red Line Shock Proof, or Castrol Syntrax seem quite popular. I have the Castorl in my gearbox, but it appears my synchro's are past it anyway!!.

Don't put the redline in, just tried it and its not good, far too slippery, Castrol Syntrax would be the better bet as it allows the synchros to bite properly.

Expensive learning excersise.

bob

Motul GEAR 300 75W-90

Put Redline in mine (my99) and it started to snag in between 3rd and 4th. Changed to Syntrax (from dealer take a 5ltr container) and have used it ever since no problems.
I change the g/box and rear diff every six months :thumb:

As Bob found out to his cost (replacement 6 speed) the Red Line is not best suited to Subaru synchro boxes.

Here are two that are suited:

http://www.opieoils.co.uk/TechSpecs/..._Auto_3178.pdf

http://www.opieoils.co.uk/TechSpecs/...04%20Wheel.pdf

Cheers
Simon

My UK MY03 or MY04 six speed has run for 17000 miles with a c.400 lbft setup with Redline lightweight and a bit of 75-90 NS on Job's recommendation, which is maybe what helps, and it seems OK. Sometimes I catch the second gear synchro on a fast 1-2 but I think that is my footwork which is lacking.

I remember Silkolene Syn-5 being an expensive mistake in my 99my It ruined the synchro performance from 4th to 5th at high revs Castrol Syntrax (Driveline) cured the problem instantly.

oh crap
 

Just order from oilman (Silkolene Syntran) :cry:

Hope I haven't been given crap advice! Let you all know on Thursday!

Mike

Further to the above found this on 22b:

http://bbs.22b.com/cgi-bin/ultimateb...=001261#000007

Maybe everything will be good? :) Till Thursday!

I changed my gearbox oil to Castrol Syntrax Driveline in the hope it would cure my slight crunches. But it didn't, no difference whatsoever. Never mind ay.

syntrax really helped my gearbox

i have the lightweight shockproof in mine and havent had any probs at all?? is it a case of one for one and one for another?? there never seems to be a definitive answer to anything anymore!!

bit concerned by wha tyou said though bob as your mapping my car in 3 1/2 weeks :S

Bob, do you think the weight of the shock proof oil you used might have made a difference?

No you haven't, I can catagorically state that this oil meets the spec you require and is a race proven gearbox and diff oil. You'll have no problems.

We have hundreds of scoobs running on this without issues.

Cheers
Simon

The weight of the oil is fine, it's the composition of the addative pack that makes it less or more slippery.

Everyone can cite a bad experience (and I'm not defending Redline here) but at the end of the day, confirming that the oil is to blame is far more difficult.

Cheers
Simon

It seems that the Subaru box prefers semi-synthetic (certainly from my experience of trying Silkolene)
It may well be the case that these oils meet the GL-4/GL-5 spec. but it doesn't necessarily mean they will work perfectly in a particular make of gearbox due to the needs of the synchro design. Castrol Syntrax is also GL5 but allowed the synchro to work properly. I suppose you could say the synthetic worked too well by reducing friction too much!!
The Silkolene Syn-5 I drained from the 99my box now resides in the box of the wifes Nissan Primera - it seems perfectly fine in there!
As a matter of interest the 99my had less than 10k on the clock at the time.
JohnD

Hi all :D,

Have a JDM STi7, 38,000 KMS, car is a MY2001.

I have basically only changed my oil (every 5,000 KMS) since I bought it, along with one new set of spark plugs and one new air filter (both OEM parts).

I assume that I should do a gear box and rear diff oil change at this stage ?

Was thinking of going Castrol Syntrax.

Is there a special type of Castril Syntrax or is there only one type ? Should I use 75/90 for both the gear box and rear diff ? How much do I need for the rear diff and gear box (don't forget I have a JDM STi7, 6 spd :D) ?

How many KMS or what is the max length of time (ie 5 years ?) before I should change the Timing Belt ?

Should I do a complete coolant change ?

Should I do a complete brake fluid change ?

Anything else needs doing on a MY2001 with 38,000 KMS ?

Sorry but there is no Subaru Dealer here that deals with JDM STI's and I don't have the service manual that was supposed to come with the car :(

Ambient temps are high here and there is lots of stop and go city driving.

BIG thanks !!! :D

Ray

:D

bttt :D

Adam yes I do, however I have driven cars with the lightweight as well with similar feel problems.

Oilman BOTH the oils you recommend are not suited to good syncro operation, this is not a question of theoretical technospeak, real world experience says that Subaru boxes DO NOT LIKE slippy gearbox oils and those include the two mentiooned by you.

Syntrax or the Shell semi-synthetic specified by Subaru are the two best.

Not IMHO either !!!

I currently am using the Sylkolene as a flushing oil to get rid of the Redline, I will be draining and refilling in a couple of weeks with the same, then after a further 2k miles I will be on the Syntrax, the STi9 is on Syntrax now, big, big improvement, thats running 375 ft lbs torque btw !!

cheers

bob

Sorry Bob, I really can't agree with your comments.

Firstly we have many scooby owners running on these oils without issues and secondly the Motul is run as is in the Subaru World Rally Team cars. How can they be no good?

Agree to disagree I feel?

Cheers
Simon

It's not a question of 'goodness', it's a question of suitability. Rally cars gearboxes don't have syncros. My gearbox works better than previously having put Syntrax in it.

please see my posts gents, thank you.....not trying to be lazy but no Subaru dealership here and no service manual with my car ...

quick one as well, is it true that if you are driving and your timing belt pops then you mess up your engine severly ?

cheers,
Ray :D

Well.. in Finland we have used GEAR 300 in several STI's and WRX's already and it seems to be the only one's (also Castrol Driveline) which works with STI MY04 and STI MY05 transmission without any problems, works a lot better than the original one!

So I don't really underwrite Bob Rawle's comments.

To my knowledge older <99 year are more picky about which oil you should put on it..

Couple of local Subaru specialist already now started using and recommend it.

In my last WRX MY04 Driveline and GEAR 300 felt exactly the same!

I now use GEAR300 also in my STI MY05 works perfectly! Also in over -15 Celsius temperatures!

Razor: You can find the answers to all your questions using the search facility. This thread is about gearbox oil - if you can't find the answers to your questions using search, start a new thread.

Fair enough, but figured since it was a gear box oil related question might be ok, I have done the search but there are so many different answers I was hoping to get a new up-to-date comprehensive answer to my service questions on this thread.

Cheers,
Ray :D

Well Bob, you certainly got me thinking and digging further on this one.

This morning I contacted both Motul and Silkolene concerning their recommended oils for the Subaru Impreza gearbox to recheck our data thoroughly and here were my findings.

Motul

Full data recieved for the following models:

Subaru Impreza 1.6 4WD 2000 onwards, Impreza 2.0i, sport 1996-00, Impreza 1.6i, 1.8i, 4WD 1993-96, Impreza 2.0i Turbo 4WD 1994-00, Impreza 2.0 4WD 2000 onwards, Impreza 2.0 WRX/STi Turbo 4WD 2001 onwards and Impreza 2.5i 4WD 2001 onwards.

Motul work on a Good/Better/Best system of recommendations and they specified as follows for all the above models:

Good = -
Better = Motylgear 75w-90
Best = Motul 300 75w-90

The only additional notes attached to these recommendations are:

"Gearbox/Differential oil viscosity recommendation: 75w-90 may replace 80w-90 in all applications.

Silkolene

Full data recieved for the following models:

Subaru Impreza 1.6 4WD 2000 onwards, Impreza 2.0i, sport 1996-00, Impreza 1.6i, 1.8i, 4WD 1993-96, Impreza 2.0i Turbo 4WD 1994-00, Impreza 2.0 4WD 2000 onwards, Impreza 2.0 WRX/STi Turbo 4WD 2001 onwards and Impreza 2.5i 4WD 2001 onwards.

Silkolene work on a best only recommendation and their reply was as follows:

We would recommend that the ideal grade is Silkolene Syn-5 which passes API GL4 and 5. GL4 includes a synchromesh test.

Note: The usual objection to "GL5 only" oils is that they can be ‘too slippery’, which slows the synchromesh engagement.

I took a look at the data sheet for Castrol Syntrax and have put the link here. It is not suitable for LSD's.

http://www.castrol.com/liveassets/bp...0_B1278983.pdf

I could not have been more thorough in my investigations and have to say that although I respect your opinion on this subject, I have to disagree with your comments.

Like everything in life there is always someone who has a bad story to tell and this normally gets the higher profile. There are many Subaru's worldwide using these race proven oils happily.

Peace Bob!

Cheers
Simon

Thanks for that Oilman, so you can't use the Castrol Syntrax with the Subaru LSD, don't the JDM STi-7 GL's have both front and rear LSD's and the STI-7 S only has a rear LSD ?

Cheers,
Ray

I just read the link and it does state clear as day 'not recommended for limited slip differentials'......hmmm, aren't lots in here using this stuff on their JDM and UK STi-7's and above which all have LSD's ?

Cheers,
Ray