Technical Gearbox oil

[JakeF]

I rang the local Penrite distributor who looked up their list of recommended oils for a Fiat 126 transmission. Penrite is a respected brand of oil in Australia. They specialize in oils for older vehicles.
He suggested an SAE 20W60 mineral oil that also doubles as engine oil ...
I questioned this recommendation but he was adamant that the engine oil would be OK.
I told him that for the last two years it's been filled with an EP oil and his response was that it would eventually corrode the brass components but it would take a very long time, longer if the oil is not getting very hot, that is, if the car, like mine, isn't driven much.
I asked if they made a non-EP transmission oil, but they don't because, you guessed it, the similar viscosity engine oil is fine in transmissions.
F**k me - now what ???
Chris

I have been told that sae 50 oil is very near to similar transmission oil(without EP) and can be used on old car transmissions.
Look at this motul:
http://motul.speclube.com/products/all-products/classic-motor-oil-sae-50-2l/

About the tutela gear oil. It is lightly added EP on it, because it should be used on non syncro boxes, right?

 

[jjacob]

Chris,

There are lots of manual transmissions that use EP oils. Some transmissions have synchronizers that are not compatible with some EP additives and so the manufacturer recommends a different oil. However, not all synchronizers are incompatible with GL-5 EP. It is a matter of what they are made from.

I again would go with what Fiat or the transmission manufacturer recommends for the particular transmission you have.

Fiat transmissions as used in the 124 series of cars recommended GL-1 transmission fluid (non corrosive-EP). Another good non corrosive-EP transmission fluid is GL-4.

I really don't think using any type of engine oil, where it was not originally specified, is a good idea.
John

 

[Peter Pick-Up]

I rang the local Penrite distributor who looked up their list of recommended oils for a Fiat 126 transmission. Penrite is a respected brand of oil in Australia. They specialize in oils for older vehicles.
He suggested an SAE 20W60 mineral oil that also doubles as engine oil ...
I questioned this recommendation but he was adamant that the engine oil would be OK.
I told him that for the last two years it's been filled with an EP oil and his response was that it would eventually corrode the brass components but it would take a very long time, longer if the oil is not getting very hot, that is, if the car, like mine, isn't driven much.
I asked if they made a non-EP transmission oil, but they don't because, you guessed it, the similar viscosity engine oil is fine in transmissions.
F**k me - now what ???
Chris

Ask Penrite themself by mail, and keep the written recomendation...!!

 

[Peter Pick-Up]

But you have to remember it's a 50 years old car. The factory/service manual gives you the correct information, that's my opinion. Just like John said.

Most recommendations from that long ago, are no longer available today for sure,oil technology has come a long way since the sixties....!!

 

[jjacob]

Most recommendations from that long ago, are no longer available today for sure,oil technology has come a long way since the sixties....!!

Not true, almost all oils recommended years ago are still available today.
I agree that oil technology has come a long way, but some of the new oils (specifically synthetic) are not compatible with older seal materials. Synthetic oils are often too slippery sometimes for some older manual and automatic transmissions to function correctly.
John

 

[Peter Pick-Up]

No modern (synthetic) oil will do any harm to an oil seal that is in good condition....myths from the stone age.
And synthetics are no more "slippery" than any other oil with the same viscosity, again myths from hearsay.

http://www.bobistheoilguy.com/

 

[jjacob]

Here is an interesting explaination from Saab on why engine oil or EP oil is used in certain gearboxes.

http://townsendimports.com/Web/transmission_folder/spovgearboxlube.htm

 

[Peter Pick-Up]

We all know what happened to Saab...!
Saab, as a small car manufacturer, never designed their own engines, instead they bought the V-4 from Ford, and later for the 900 series, they bought Triumph technology from good old Britain...!
Just for the record....

 

[jjacob]

Peter,

Just for the record, original two stroke engines were designed by Saab. The V4 came from Ford (as you stated). The original 4 cylinder engines for the 99 came from Triumph. But the later 1973 onwards 2 litre engines were Saab designs and built, and had relatively little in common with the Triumph engines. These engines were built, redesigned, and continued in development well after British Leyland disappeared.
I have had many Saabs over the years: 96, 99, and 9000.

However, this is all off topic. If you are discounting the information I posted from Saab on the conditions under which engine oil would be used in a transmission mearly because they have unfortunately gone out of business, that seems unfounded, especially from a moderator.
John

 

[Peter Pick-Up]

No, just some small talk, that's all..
The Saab two strokes were licensed from German DKW if I'm not mistaken...!
In the former Saab museum in Trolhatan ( I've been there twice..) they showed a very interesting 6 cilinder two stroke...!! ( basicaly two engines joined together..).

 

[Bambino]

Chris,

There are lots of manual transmissions that use EP oils. Some transmissions have synchronizers that are not compatible with some EP additives and so the manufacturer recommends a different oil. However, not all synchronizers are incompatible with GL-5 EP. It is a matter of what they are made from.

I again would go with what Fiat or the transmission manufacturer recommends for the particular transmission you have.

Fiat transmissions as used in the 124 series of cars recommended GL-1 transmission fluid (non corrosive-EP). Another good non corrosive-EP transmission fluid is GL-4.

I really don't think using any type of engine oil, where it was not originally specified, is a good idea.
John

Thanks John.

I'm really not keen on putting engine oil into my gearbox/differential so what I intend to do is hunt around for a non-EP transmission oil as that seems the safest thing to do.

I drained the oil last night and will start a 'literature search' to try and come up with some answers, least of all for my own peace of mind. My transmission was originally from a Polish Niki and unfortunately virtually all technical references to the Niki 650 (= Fiat 126p) seem to be unobtainable though in truth I probably don't need them as when it was rebuilt a couple of years ago, I used Italian-made Fiat 126 bearings and synchros. I was told at the time that they were compatible with modern extreme pressure, sulfide/phosphor containing oils. I still have the receipts, so I'll start there.

Thanks again for your help and apologies for the potty mouth (I can get a lot worse, particularly when my footy team is losing )

Chris

PS: I too owned a Saab about 20 years ago - a manual 2.0 litre coupe (Saab 900) - it was a great car. I sold it to a mate of mine who took it interstate and drove it for another decade or so before it finally died. He loved it too.

 

[Peter Pick-Up]

All synthetic Castrol gear oils are GL-4!
I use Castrol Syntrans Transaxle 75W90 in all of my Fiat and Alfa's, perfect product and GL4+.
For older cars with less horsepower, Castrol Syntrans Multivehicle 75W90 GL4 is a good choice.

http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9014024&contentId=7071035

 

[jjacob]

Hi Chris,

As you have been so kind in helping myself and others I thought I would do some research for you on the proper transmission fluid for a 126 synchro transmission this Saturday morning.

I found a site that had both 126 and 126bis manuals for download. The site is at: http://www.126bis.de/en/index.html
For both transmissions the proper factory oil is...

Tutela ZC 90 80w/90 non-EP gear oil

I have attached the documentation. The German text translates as: "Viscosity properties of the oil for mechanical transmissions no ep"

Link to oil specifications: http://126bis.de/en/126bis.html#betr

Link to thread on alternate oil brand than Tutela: https://www.fiatforum.com/uno/297181-gearbox-oil-alternative.html
You can do a general search on the entire FiatForum site for: "Tutela zc90" and check for additional information.
It is possible that Peter's recommendation above may be a suitable replacement, but I will leave that research to you.

John

 

[Bambino]

John,

Thanks for this - I really appreciate it. Not only does it help me, but also many others who restore/modify these little cars.

Chris

 

[the hobbler]

Thank you everybody for your time and input---it has been most interesting and informative---here in the UK, I think that the best answer would be the Castrol 75/90 gearbox oil, especially as it can be bought from Halfords. I also think that I will stick to Castrol Classic 20/50 oil for the engine. Whatever you decide gentlemen, happy motoring.

 

[Bambino]

I made a few phonecalls today - Tutela oil is not available in Oz but Castrol 75/90 is, so I'll order a few litres and store it downstairs next to my turntable and all of those blank Betamax video cassettes I bought years ago ... only difference is, the oil will get used

Thanks again.

Chris

 

[Damon500]

Interesting topic, I have experimented with a variety of different transmission oils in 500's and 126's. The Castrol Syntrans works well and 126 Synchros are very robust, the synthetic oils seem to prolong the life of the first gear and cluster which is a useful side effect. Tutela oils are available in Australia through Fiat and Alfa dealers- I have been running ZC75 Synth in recent years in my 500 with Niki gearbox (and 5 speed conversion) and so far all seems good. Off Topic I have been also running Selenia racing 10W60 in the standard (Niki) engine which has kept it healthy at 120,000km+ despite my best efforts to break it (Sydney to Melbourne in a day at 38 degrees and then 6000km in 4 weeks through Europe...) Certainly I have no complaints about the quality of FL Selenia lubricants!

 

[Bambino]

I've bought 4 litres of Castrol Manual VMX-M 75W-85 manual transmission and transaxle oil. It is an API GL-4 oil and the guy in the shop assured me that it would be OK in my gearbox - though I've heard that before ...

Any comments before I put it in ?

Chris

 

[the hobbler]

Hi Chris;
Try dropping Castrol Technical department a line and asking their opinion---if they they can't get it right, who can?

 

[Damon500]

Hi Chris, VMX works fine- we used to use it for the Fiat/Alfa Transaxles for several years prior to the Selenia products being made available in Australia and it is equivalent to the Selenia ZC75 Synth I have been using. One of the Castrol Australia technical advisors is a member of the Fiat Car Club of Victoria so if you get Gary on the line he definitely knows both his Fiats and his Oils!