I have noticed that I have bought GL-5 oil instead of GL-4 oil, as it states in the 1997 manual.
I presume it makes no odds and is perfectly safe to use?

Tom.

The gearbox requires GL4. GL5 contains different additives and may cause selection issues. You must also ensure that the oil is NOT EP. Sadly, GL4 & GL5 can be had as EP or non-EP, and the labelling is often not clear. If it says EP, do not use it. The synchromesh requires some oil drag to operate properly, the EP spec reduces this, often resulting in crunching into gears. EP usually says so on the label somewhere, although may be in the small print. Non-EP is often difficult to be sure. EP has a strong sulphurous smell.

Oh bugger. Here's a photo of the product plus a link to the data sheet and everything says 'EP'. It does mention in the data sheet that it is also GL-4 but I don't suppose that changes anything?

Tom.
http://www.greenstar.it/portals/0/schede/112139_scheda tecnica.pdf

tolerance data shows gl4

Things seems to be getting a little murky. That screen grab shows 'EP' as being acceptable.

Tom.

The screen grab is not Fiat data.
We're all using the same gearboxes. Your handbook probably demands Tutela something, which is non-EP.

EP was used in gearboxes many years ago, but not really since the eighties. Without the EP additives, gear changes can be softer with less effort, so gearboxes have been engineered to suit.

EP now really only used in rear differentials, where the drive has to be turned through 90 degrees, using hypoid bevel gears that have a sliding action, rather than the normal push in gearboxes and front-wheel-drive differentials.

This thread triggered my interest as may have explained why my gearbox is dying since most oils out there are EP, and I have replaced the oil in my box with EP type for sure. However I checked the mk1 handbook which seem to specify SAE 75W, 90EP oil that meets API GL5, (Tutela ZC 75 SYNTH). I also checked MK2 handbook which specify same oil. After some google search I seen that if the box has yellow metals synchros then EP should be avoided as the EP ingredients eat the metal, and hence damage the syncros. So if Fiat use yellow metals for the syncros and recommend EP oils then many people will be affected.

I'm surprised that your handbook states EP.
Checking the downloads, there is no handbook for a Mk1, but the Mk2, see pic below definitely does not state EP.
Non-EP oils are out there, but can be hard to find, mostly because the sellers do not understand the differences, and just stock the easiest/most popular. Catch22, they are most popular because that is all they stock!
Most front-wheel-drive gearboxes do not require EP oils, so many will now be filled with incorrect oil, as a result of the trade not paying attention.

Halfords do stock a Castrol non-EP oil. Other stockists may, but you have to be prepared to search and demand it.

If EP has been used, it will take a long time to get rid of. Change the oil, run it for a few weeks, and drain it when hot.(careful of burning fingers) Expensive, but replace several times until the nasty sulphurous smell is gone or nearly gone. EP clings well and stays.
When the Rover SDI was introduced in 1976, the gearbox actually used auto transmission fluid. The filler hole was in a difficult place, resulting in an apparent need to top up, even when full. Many were wrecked by just being topped up with EP. It would take just a couple of weeks to destroy the synchromesh.

http://www.eurocarparts.com/ecp/p/c...nual-transmission-fluids/?522776052&0&cc5_868

Sorry, UK suppliers are of no use to the OP.
Have a look here: http://www.greenstar.it/Prodotti/LubrificantiAutotrazione/Olipertrasmissioni/tabid/64/Default.aspx
DENTOL ZC 90 (SAE 80W/90) is the product you need from that supplier.
Click on "Immagine" and then magnify the label to read the bit about "without hypoid gears".

I've just noticed that my manual indicates 'EP', see photo below.

Tom.

strange, i have uploaded haynes for mk1, looks like admins deleted it

https://drive.google.com/folderview?id=0B6X7mqLVnIypQzdPQ1h5ZllxZms&usp=sharing

as i have said many times, we cannot host haynes manuals on the forum - its copyrighted material and they have actually contacted the forum in the past because they found out there was a haynes manual hosted here... If you wanna post link to external sources then thats totally fine, we have no control over what other people have on their sites but we cannot have them actually hosted here.

on the actual topic, in all my previous FIRE engined cars Tutela ZC 75 Synth is whats been recommended in manuals and handbooks, and it is what i have used and I never had any issue with it - pretty sure this has EP additives in it. I actually have some in the garage now but I recently ordered Some Tutela ZC 90 for my panda was thats what my manual said - that i believe is not an EP oil but perhaps a little thick for a mk1 box???

No expert, don't claim to be, I just go by the manual usually and thats served me well so far - although the cento manual says the box takes way more than it does (hence my spare ZC75 lol), so they are not always correct!!!

Hi,
I've used BG 75W90 GL-5 gearbox oil in my 1995 Punto 90 Cabrio.
It does not have a FIRE box.

Should I change back to GL-4 oil?
Should I use 75W85 instead or stay with 75W90?

chesh said:

Hi,
I've used BG 75W90 GL-5 gearbox oil in my 1995 Punto 90 Cabrio.
It does not have a FIRE box.

Should I change back to GL-4 oil?
Should I use 75W85 instead or stay with 75W90?

Click to expand...

Well it is my fairly recent understanding that the 90 uses a FIRE box with a different bell-housing.

www.castrol.co.uk

"Oil Selector".