gearbox oil

Hi all, long time no write (but plenty of lurking)

About to do one of the most disgusting, stinky messy jobs of all time. And I don't work at KFC.

Been to BITOG, castrol, google, AVD and there's not exactly a wealth of info around on changing/upgrading your gearbox oil. What do you guys use (those who've ever bothered to look at the boring workhorse in front of the engine)?

About the only thing I'm reasonably certain of is that I'll be using GL-4 rated oil. I've heard good things about syntorque, but it's not something you see on the shelf at repco.

I've got a bottle of Castrol syntrans 75w-85 which is GL-4 and expensive enough that it should double as a GPS and cook dinner for me. Thoughts? Experiences?🤖🤖🤖🤖

Peter Leonard wrote:Hi all, long time no write (but plenty of lurking)

About to do one of the most disgusting, stinky messy jobs of all time. And I don't work at KFC.

Been to BITOG, castrol, google, AVD and there's not exactly a wealth of info around on changing/upgrading your gearbox oil. What do you guys use (those who've ever bothered to look at the boring workhorse in front of the engine)?

About the only thing I'm reasonably certain of is that I'll be using GL-4 rated oil. I've heard good things about syntorque, but it's not something you see on the shelf at repco.

I've got a bottle of Castrol syntrans 75w-85 which is GL-4 and expensive enough that it should double as a GPS and cook dinner for me. Thoughts? Experiences?🤖🤖🤖🤖

Hi Pete
Yes the hypoid oil does stink like no other oil... lol

I did fill My gearbox up with Castrol syntrax synthetic oil...

I have used 85w90 hypoid [GL4] oil before...
along with a MOLYBOND type additive..

only problem with synthetic oil is it seeps along the threads of studs and the bottom of My gearbox is always wet, although it never drips... lol

best to buy a litre a month... lol at those prices...

cheers

LEE

cheers Lee, apart from all the leaks (expected in VWs) anyone else tried a synthetic like Syntrans? Not a big fan of additives (if they were really worth it I expect they'd already be in the oil off the shelf...)

Hey dude,

I put Castrol Syntrax 75-90 in my gearbox several years ago (most I've paid for 3 litres of oil) and it shifts fine both when it's hot and cold.

Gracey wrote:Hey dude,

I put Castrol Syntrax 75-90 in my gearbox several years ago (most I've paid for 3 litres of oil) and it shifts fine both when it's hot and cold.

My original gearbox was sitting for 8 years with new GL4 hypoid oil in it...
which is what You don't do...
it eats into the brass/bronze bushes....

in the USA during winter they use another oil while the car sits out the winter away from the salt on the icy roads..
as its written in manuals over there...

the MOLY ADDITIVE stopped all the whinning over a 6 month period and I could eventually hear My radio etc...
the additive was PRO-MAR .. I triple dosed too..
highly recommended...

I have no additives in My gearbox now... [another gearbox]

Lee

The syntrax 75-90 is GL-5

Actually from what I've read it's the GL-5 that has the higher amount of EP additives which tend to attack 'yellow metals'. My Castrol SynTRANS 75w-85 is GL-4. GL-4 is supposed to have half the quantity of the naughty stuff in it. The only reason I'm doing this is i have a sneaking suspicion that thirty years of abuse may have left me with SFA of anything vaguely oily in the gearbox.

OT- Good to see you haven't turned into a melon Andrew 😀 How're your eight plugs doing these days?

i use this http://www.penriteoil.com.au/pis_pdfs/Hypoid%2085W-140%20JAN%202010.pdf

look and you will see its gl5 ,which affords MUCH better protection than gl4 AND it does not attack copper alloys,i also put a tube of molybond in as well, its the ducks guts for rotating parts

Yeah that right 50% more additives, I haven't had any problem yet, touch wood. This is the oil Greg Ward uses in his hillclimb car, or at least was using when he recommended it to me.

No mate, haven't turned into a melon yet, the eight plugs are doing just fine.
Good to see your still kicking.

I think the MT-1 spec means it's safer for corrosion, but GL-5 _appears_ to be designed for different usage...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1157073

Really handy site for those more interesting in learning than flaming 😉 I'm still driving my hillclimb car every day (when I'm not on the ZX-9). Hell... my hillclimb car has crossed Australia 3 times since we last spoke 😀

Theres over 13 pages of GL-4 vs GL-5 thread on thesamba

General consensous seems to be that todays GL-5 are fine for our gearboxes, it was the early original released stuff that wasnt

Noones been able to back up with facts that modern GL-5 is detrimental
But several people have run GL5 for plenty of miles with no issues

My gearbox has never had an oil change since it was built 9 years ago, I'll probbaly be a guinea pig and put GL 5 in it

Guess I'll wander on over to TheSamba and have a squiz. It's interesting how few people seem to worry about the gearbox; most likely a function of them being so well built at the outset. Got to love working with cars that have been over engineered! Go the VW.👍

Peter Leonard wrote:cheers Lee, apart from all the leaks (expected in VWs) anyone else tried a synthetic like Syntrans? Not a big fan of additives (if they were really worth it I expect they'd already be in the oil off the shelf...)

Hi
Well, after the NOISE that was in My gearbox for a few months.. [didn't do many kms]
too loud to have a radio or talk to someone...lol
but just suddenly, it reduced to half the noise one day...
and again later on.... so the Additive did work...
and was needed...

otherwise I probably wouldn't have put it in... lol

but I also know that MOLY grease [lithium based] will stop noise in a worn out CV Joint....
and probably stop any further wear... [hopefully]
[that was in a Magna]

so the MOLY debniumdisulfide [My own spelling] does really help if there is wear... and there probably most likely be a bit of wear in Our over engineered German made gearboxes.. lol

LEE



but it shouldn't hurt either... lol
I'm now going to add some valvesaver to My 95 RON fuel..

http://www.ratwell.com/technical/GearOil.html

I think I'll stick with my GL-4 🙂

Peter Leonard wrote:http://www.ratwell.com/technical/GearOil.html

I think I'll stick with my GL-4 🙂

Hi Peter

We'll be nuts after reading all that info... GL4 YES GL5 NO
or maybe...lol

what I was told from the USA... gearboxes sitting for a long time with hypoid oil in them is the major cause...
the copper/bronze etc is attacKed while everything is still

once its running in a car.... NO Problems.....??

I believe GL4 will also eat Your bushes etc if Your gearbox sits there for many years....lol

using it all the time.... shouldn't be a problem...

cheers

LEE



LEE

Really from what I can gather the GL-5 is pretty safe until the oil gets hot, which accelerates the chemical reaction between the sulfur (common EP additive of which there is USUALLY more in GL-5) and the 'yellow metal' components (syncros bushes etc..) It's going to take a loooong time to do any serious damage, at which point the EP additives have probably done more good than harm in relation to the cushioning effect on spider gears and other places that bear the brunt of clutch dropping.
...of course if you don't hammer the crap out of your gears the thrust faces will be perfectly fine with the oil type VW recommended, along with the shift forks, syncros and bushings. As my gear box is an original '71 never rebuilt I'm perfectly happy sticking with GL-4. Any wear in there now is NOT going to be offset by throwing in EP GL-5. I'm even going for horrifyingly expensive fully synthetic GL-4 to see if Hoobs likes it. If [when] I get a sexy new gearbox built I'll probably take the advice of whoever builds it, or go for a specific GL-5 MT-1 (which should be yellow safe).

I think I'll start a thread on 'what's the best engine oil?' 😁🤘😂🥷🥷😉😉

Hi,
I have been running a redline synthitic in my gearbox for 3 years with a improvment in shifting and general quiteness,
the oil is very thin but has a gear tooth loading much higher that ep90 so there is a major reduction in wear and noise, quite expensive, phone redline and talk to there engineer to get the correct one for your aplication

THE CASTROL SYNTRAX IN MY gearbox cost Me about $35 a litre when I bought it...

I saw recently some NULON 1 litre of 75/85 or 90??
100% synthetic transaxle oil for $14 a litre???

YIKES...

and 15w/50 NULON engine engine oil for $25 for 5 litres....
and SL specs not the new SM...

and synthetic engine oil for $32 for 5 litres..??

just remember You have a differential in Your transaxle..

so extreme pressure hypoid oil is needed IMHO...

LEE

I'm running GL4 hypoid oil. Don't remember what. I got it from western oil. The bloke at the counter went through the additives with me to make sure it was safe. 4L only cost me 30 odd dollars. I like buying things from industrial / commercial suppliers. Good products without the BS and much lower prices.

How is it?

Better than the black stinking thin fluid I drained from it. It's a bit quieter now. Might try some of the molybond stuff in it, as an 1800 type4 with an early 3 rib in a type2 is a dangerous combination.

ODD but true... lol


I had an L300 back in 1982> and it was recommended by Mitsubishi to change the gearbox oil and replace it with Automatic Transmission fluid...
if You had problems shifting gears when cold..
which I did have...

so, it had ATF in it... lol

LEE

Times have changed and and the use of synthic oils in automotive and industry is now the norm, i work for a oil company and am heavily involved in the maintanence of all rotating equipment used in the process of hydrocarbons,we use exclusively synthic oils and grease resalting in a improvment in relyability and less downtime, the oil that i use in my gear box is the redline transaxle oil and does not fit the general discription of hypoid gear oil, it is extremly thin and you can actually feel the polimers in the oil, these give you the increase in gear tooth contact pressure without the oil being a 90 weight, a major decrease in effort required to change gears , the oil is not hydroscopic so there is no water obsorbed into the oil during it's life time in the gearbox unless you think your car is a boat, i have had the oil sampled and after 3 years there is no need to change it as there has been no deteriation, cost effective and justifying the high purchase price

All done, will let y'all know if it's good, bad or ugly. I ended up using two GL-4 oils mixed together. Not because I'm a chemical engineer with pretensions of grandeur, simply because Supacheap had a 20% off sale and they didn't stock Castrol Syntrans, only Syntrax. So I bought 2L of equivalently expensive Nulon fully synthetic GL-4 75-W 85 and chucked it in with the 1L of 75W-85 Syntrans i got at Repco. Scored a really cool oil pump siphon thingy at the same time which made it realllllly easy too 😀

The stuff that came out could have been anything: it was pretty bodgy, sulfurous and full of brass flakes, and the magnet on the tranny drain plug was liberally coated in steel shavings and sludge. About 2.5 litres of the pristine pale yellow fluids replaced it and made me feel all warm and fuzzy. Tomorrow my gearbox will probably have a nervous breakdown and spit the diff straight through the floorpan.

Is 90 bucks worth of oil going to be worth it? Who knows. Even if it isn't I'm going to tell everyone how it increased horsepower, quietened down my gearbox, made shifting silky smooth and effortless, and enabled me to finally break the 13 second 1/4 mile in my daily while sipping a macchiato and writing the archetypal great Australian novel. It's all about the Volkswagen.

Wish I had one of those pump things, but they were all out. I made a pressurized lid for the oil with an in hose and an out hose.
Pressurized the oil container with a compressor going very carefully on the trigger of the air gun. Did the job at least.

Since the oil change there has been oil coming out at the shift rod on the cone. I choose to ignore that.

If you're looking for something close to original,

Penrite manual gear oil 80

SAE 80/85 API GL4

This is NOT a hypoid oil, so you don't have to worry if your car does extremely low miles, or you want to shelve a transaxle for a while.

I bought some today - from Bursons - 20 something bucks, 2.5 litres. A bit short for a type 1 transaxle but you only have to buy 2 bottles now and then. You've always got the leftover from last change to make up the difference.

I also use a large tube of Nulon GL70 gearbox treatment, good stuff.

As for filling, I use a 6ft (or so) length of garden hose with a funnel stuck in the end, if the car is next to something suitable (fence, garage wall) you can screw, nail, tape the funnel to it and then crack a beer and keep going back to top the funnel up until the filler hole starts overflowing.

If you have a sloping driveway, drive the rear of the car onto ramps to utilise the slope to give you maximum room to work.

For beetles, while climbing the ramps open your door and place a spirit level on your running board and you'll be sweet if you stop when the bubble does its thing.

Regards,

Matt.

General_Failure wrote:Since the oil change there has been oil coming out at the shift rod on the cone. I choose to ignore that.

Hi
You can buy those seals and brass bushing as an assembly..
I bought Mine from the USA but I'm sure they would be available at a VW parts shop...

maybe You put too much oil in the gearbox..
and the bush/seal is worn....

but its better than too little oil ... lol


LEE

Matt Ryan wrote:I also use a large tube of Nulon GL70 gearbox treatment, good stuff.

For beetles, while climbing the ramps open your door and place a spirit level on your running board and you'll be sweet if you stop when the bubble does its thing.

Regards,

Matt.

Matt

Can You use GL70 Nulon additive in synthetic oil ???

LEE

Matt Can You use GL70 Nulon additive in synthetic oil ??? LEE

Lee,

I was looking at Nulon synthetic gear oil today and the label said... "for added protection, use Nulon GL70"

Can't see the value in paying a premium price for synthetic oil, then paying for an additive as well. Why don't they just put the stuff in their "you beaut" oil?

Don't get me wrong, I've been using (and running the bullshit microscope over) Nulon stuff since the late '70s.

Regards,

Matt.

I've been using their products since the 70s also but haven't used their oils as yet...

I do have a couple of tubes of GL70 ...

I thought it was odd that their oils do NOT contain their additives

Not sure whether it still says that on the oil containers now...


LEE

Hi

I put some GL 70 in my sons transmission. It improved the cold shifting unbelievably, we have a tight 2nd gear corner about 500 metres from our house, it was always a struggle to get back to 2nd when trans was cold, its now a breeze.

I'm a Nulon fan, one of our club members is one of the Phobas there I've done the factory tour and I believe in the product, they also sell 20 litre drums of the product, a bit of money to be saved there, not so much for trans oil unless you own a fleet of cars but good for motor oil.

Steve

Yeah Lee,

I think they have "some" of their magic ingredients in their oils,
but not too much to prevent selling more product.

They make some very good high temp grease as well.


A small tube of GL70 comes in real handy for assembling rear wheel bearings and seals on swingaxle models. It makes a good initial lube for the bearings and keeps the rubber in the seals & O rings supple as, for ages.

Regards,

Matt.

So that's a few hands up for the Nulon GL70 additive? 🙂

I can't remember -- are you supposed to fill the tranny with the rear axles under load or jacked up?

I have always used Castrol VMX80 GL4 rated

oval TOFU wrote:So that's a few hands up for the Nulon GL70 additive? 🙂

I can't remember -- are you supposed to fill the tranny with the rear axles under load or jacked up?

I have IRS and cv joints so I don't know... ??

I would presume with the axles down...???

never ever thought of that....

more oil the better... with oil filled axles..??

LEE

68AutoBug wrote:

General_Failure wrote:Since the oil change there has been oil coming out at the shift rod on the cone. I choose to ignore that.

Hi
You can buy those seals and brass bushing as an assembly..
I bought Mine from the USA but I'm sure they would be available at a VW parts shop...

maybe You put too much oil in the gearbox..
and the bush/seal is worn....

but its better than too little oil ... lol


LEE

Nah. Couldn't be too much oil, unless I found a way to fill it past the filler plug.

What are the seals and bushes called? As it is it is missing nearly every seal from bumper to bumper. been slowly rectifying that.

vwo60 wrote:Hi,
I have been running a redline synthitic in my gearbox for 3 years with a improvment in shifting and general quiteness

I'll be replacing my gearbox oil in my Golf soon to (yes I know, a very differant tranny setup compared to a Beetle)
Everything I've read says that Redline make some of the best gearbox oils out there. Sourcing the stuff locally can be hard though.

Yet I'll be a hypocrit by using a differant synthetic that we used in my dads Ute.🙄

I believe its called Marque 75W/90 API: GL5 MT-1 and it significantly improved the Bravo's cold shifting over the first 30km's the car was driven after the change. A fully synthetic oil too.

Be nice to know if anybody else has used this stuff, because if it lets me down, then Im going straight to Redline. I might also have to try the G 70 additive from Nulon, we sell it at Supercheap so I might just grab a tube next time Im on.

Keep this thread going, gearbox oils is a surprisingly interesting subject🤓

I cant remember what i used.
But its not that bad of a job.
I did it without even using a jack,in about 30mins.😀

Hi

part number for bush with seal

131 301 225B from CIP1

seal part number seems to be the same?
15mm x 24mm x 7mm wide...

LEE

check out; 131 301 225B CIP1

oval TOFU wrote:I can't remember -- are you supposed to fill the tranny with the rear axles under load or jacked up?

Fill it with the car sitting level on the ground, not jacked up.

The fill bung is higher than the axle tubes so the oil flows out into them.

Unless you have a slammed car with bulk camber you shouldn't have any dramas.



Smiley 😎

jjwebb123 wrote:I cant remember what i used.
But its not that bad of a job.
I did it without even using a jack,in about 30mins.😀

Can't remember if it has been said, but remove the filler plug first, people!

It is an easy job. There have been many a person left up the creek by draining their tranny oil then discovering they can't get the filler to undo.

I bought a tool off ebay or oztion a while back for undoing those plugs. It's pretty much a bolt head welded on to a strong bent bit of bar. Does the job great. Filler and drain plugs are in fear of me and my mighty leverage!

Speaking of which, anyone know, or is the seller of them? They also made VW valve spring compressors and trolley jack mount engine cradles. Really wish I'd bought one of the spring tools when they were selling them.

Ah, so one needs to put the car on ramps in order to get to the filler plug. I can vaguely remember doing that 'correctly' many years ago. I now just jack up the rear, take off the left wheel and fill up the oil until the oil level hits the bottom of the filler hole. So when the axels are under load again (with my negative camber) there will be more oil in the actual gearbox. I hope that's not what is making the 'box leak a little from the over filling...

There's no way I'd be able to access the filler without jacking up the bug.. It doesn't have the approach angle clearance for car ramps either!

YES....

that refill plug can be very difficult to undo....

but doesn't need to be done that tight....

its a a tapered thread...

I used a couple of nuts welded onto a bolt then cut the bolt off.

LEE

I just went to the shed to see what type of oil it was. It is GL4 and has heaps of fancy sounding grading crap. But what stood out is it says universal gear oil. What's in a name? Well if it is not right at least it hasn't been driven far. Probably less than 50km. No matter what it has to better than what I believe to be 35+ year old battered hydrocarbon soup that used to be oil a long time ago.

Can't remember if it has been said, but remove the filler plug first, people! It is an easy job. There have been many a person left up the creek by draining their tranny oil then discovering they can't get the filler to undo. I bought a tool off ebay or oztion a while back for undoing those plugs. It's pretty much a bolt head welded on to a strong bent bit of bar. Does the job great. Filler and drain plugs are in fear of me and my mighty leverage! Speaking of which, anyone know, or is the seller of them? They also made VW valve spring compressors and trolley jack mount engine cradles. Really wish I'd bought one of the spring tools when they were selling them.

Tristan,

He goes by the username yasdnil01. He gets on here, so shoot him a pm. He is also on ebay and oztion using the same name (Lindsay, spelt backwards)


Regards,

Matt.

oval TOFU wrote:Ah, so one needs to put the car on ramps in order to get to the filler plug. I can vaguely remember doing that 'correctly' many years ago. I now just jack up the rear, take off the left wheel and fill up the oil until the oil level hits the bottom of the filler hole. So when the axels are under load again (with my negative camber) there will be more oil in the actual gearbox. I hope that's not what is making the 'box leak a little from the over filling...

There's no way I'd be able to access the filler without jacking up the bug.. It doesn't have the approach angle clearance for car ramps either!

Chris,

You could always jack it up then set it down on the ramps to get the axles loaded & give you room to get in. You would then need to move your jack around to the front and use the spirit level on the running board trick to get the whole car level.

Much easier to use a mechanics pit if you can dig one in your garage😂


Regards,

Matt.

Matt Ryan wrote:

Can't remember if it has been said, but remove the filler plug first, people! It is an easy job. There have been many a person left up the creek by draining their tranny oil then discovering they can't get the filler to undo. I bought a tool off ebay or oztion a while back for undoing those plugs. It's pretty much a bolt head welded on to a strong bent bit of bar. Does the job great. Filler and drain plugs are in fear of me and my mighty leverage! Speaking of which, anyone know, or is the seller of them? They also made VW valve spring compressors and trolley jack mount engine cradles. Really wish I'd bought one of the spring tools when they were selling them.

Tristan,

He goes by the username yasdnil01. He gets on here, so shoot him a pm. He is also on ebay and oztion using the same name (Lindsay, spelt backwards)


Regards,

Matt.

That sounds familiar. thank you very much Matt!

Well... first 600ks and all's good. Interestingly the shifter rattle has disappeared, even though it would normally be attributable to a worn shift rod bushing. Gear changes are snick snick easy (not that they weren't easy before). Side note: Castrol VMX 80 is interchangeable with the GL-4 Synthetic. Castrol Website recommends the VMX 80, but if you're looking to throw away thirty bucks a litre You have the option of upgrading. My Nulon/Castrol mix feels happier than wtf was in there previously (including the mass of gluggy metal stuck to the magnet on the plug).🥷

]


IThey also made VW valve spring compressors and trolley jack mount engine cradles. Really wish I'd bought one of the spring tools when they were selling them.

My Son has the spring compressors and trolley jack mount etc..

Make taking the engine out and moving it very easy...

LEE

Peter Leonard wrote:Side note: Castrol VMX 80 is interchangeable with the GL-4 Synthetic.
Castrol Website recommends the VMX 80, but if you're looking to throw away thirty bucks a litre You have the option of upgrading. :

Now You tell Me.....

I think VMX 80 is just a dino version straight 80W oil. maybe. either way volksies would probably stand canola oil without baulking if they're not driven hard 😀 I'm just glad not to have to think about the crap flying around inside the gearbox for the next 500 years 😵‍💫

Matt Ryan wrote:

oval TOFU wrote:Ah, so one needs to put the car on ramps in order to get to the filler plug. I can vaguely remember doing that 'correctly' many years ago. I now just jack up the rear, take off the left wheel and fill up the oil until the oil level hits the bottom of the filler hole. So when the axels are under load again (with my negative camber) there will be more oil in the actual gearbox. I hope that's not what is making the 'box leak a little from the over filling...

There's no way I'd be able to access the filler without jacking up the bug.. It doesn't have the approach angle clearance for car ramps either!

Chris,

You could always jack it up then set it down on the ramps to get the axles loaded & give you room to get in. You would then need to move your jack around to the front and use the spirit level on the running board trick to get the whole car level.

Much easier to use a mechanics pit if you can dig one in your garage😂


Regards,

Matt.

Heya Matt!
Good suggestion - I COULD do that, if I cared enough! hehe. I just top it up with the axles unloaded - I figured that the gears are simply a little bit more submerged in oil than 'normal'. It's not like an engine where too-high oil level will increase oil pressure and bust seals... 🙂

i overfilled mine by about 100 ml to allow for 'spot marking'.

bit extra can't hurt; worst thing is probably frothing, but with the new super ultra additives it will be a cold day in hell before my gearbox gives a toss. How does one overfill? drive the front up on ramps and jack the back up as high as a supacheap trolley jack will get you. it doesn't get as high as the front. 🙄