Lancia Motor Club

Model Technical and Interest => Flavia => Topic started by: Angle Grinder on 04 May, 2017, 02:51:56 PM



Title: Gear Box Oil
Post by: Angle Grinder on 04 May, 2017, 02:51:56 PM
Out of interest, which Gearbox oils are other Flavia owners using?

I have been using Penrite GB40 for the last few years as it doesn't have any nasty additives, but it is probably a thicker oil than I should be using.

A specialist suggested Millers Oils classic EP80w90 GL4 gear oil, but I'd be interested in other people's experiences.


Title: Re: Gear Box Oil
Post by: lancialulu on 04 May, 2017, 05:09:59 PM
Castrol ST90 is Lancia approved gearbox oil which I have used previously but I am going to use fully synthetic Mobil 1 SCH 75-90w recommended by folk in Norfolk.


Title: Re: Gear Box Oil
Post by: peterbaker on 04 May, 2017, 07:25:30 PM
Expanding the subject: Do any owners use an additive in their Flavia gearbox?


Title: Re: Gear Box Oil
Post by: roddy on 06 May, 2017, 10:12:47 PM
In a Fulvia and Flavia you MUST use a GL5 gear oil.  GL4 is for in-line gearboxes or those on the end of transverse engines.  A Flavia and Fulvia with is bevel final drive using the same gearbox oil, it has to have 'hypoid' high pressure characteristics akin to the old Hypoy 90 originally used.  The only downside of using a full synthetic 75/90 is an increased noise as the thinner oil does not have the same deadening effect, but the considerable benefits outway this aspect.

As Tim suggests, Mobil SHC is good, as is Redline.

Regards - Roddy


Title: Re: Gear Box Oil
Post by: lancialulu on 07 May, 2017, 07:21:49 AM
Roddy is quite correct re ST90 which is not an EP / GL5 so CANNOT be used for Fulvia or Flavia but only in gearboxes that have seperate differential / final drive oil.... It is great for Appia/Aprilia etc.


Title: Re: Gear Box Oil
Post by: lancialulu on 07 May, 2017, 04:14:03 PM
This thread reminded me I still had to do a gearbox oil change as part of my Vignale mechanical overhaul. I had consciously waited till the car was back on the road so I could see what the gearbox was like, and also to get the oil hot before the change.

Well I saw I had 2.5l of SCH 70-90 Mobil gear oil on the shelf so a 12 mile drive and drain (both drain plugs) was done. The oil that came out was not really contaminated or black but I guess it had not been changed since the car was new or many years ago as I could not budge the dipstick....Working from under the car I tapped it free and put in 2.4l (always some old oil left) up to the full mark leaving it to find is level between the gearbox and final drive compartments before measuring.

A run round the block confirmed a silent gearbox and possibly an easier gear change - not that it was bad before....


Title: Re: Gear Box Oil
Post by: Angle Grinder on 08 May, 2017, 09:48:13 AM
Some conflicting opinions here. According to the Flavia Consortium website you don't want to use a GL5 oil. It is quite specific about this.http://www.flavia2000consortium.org.uk/Technical/techhome.html (http://www.flavia2000consortium.org.uk/Technical/techhome.html)

"Gearbox.  ALL.  (except those vehicles fitted with the big 4-speed gearbox; e.g. the Flavia 2000LX berlina and the the Flavia 2000 coupé - see note 21 below)  If you check in the owner's handbook, then you will see that Lancia & C specified oils such as Esso GX90 and Mobilube HD90.  These are your good old-fashioned  90 grade "light" hypoid oils (service grade GL4 or less), not these thin 75/90EP GL5 oils that are used today.  Do not use a synthetic gear oil, but obtain a similar SAE90 oil from a classic car oil specialist such as Morris's of Shrewsbury, or Millers, or Penrite for example.  These may be expensive, but do last a very long time.  Synthetic oils will cause damage."

I'm told that the originally Mobilube GX90 and Esso GX90 (as recommended in the Flavia owner's manual) is the equivalent of today's Castrol EP90 (GL4) and Millers Classic Pistoneeze Gear Oil 80w90.


Title: Re: Gear Box Oil
Post by: Brian Long on 08 May, 2017, 11:52:07 AM
Some Flavias share the differential oil and the gearbox oil. Others e.g. Flavia 2000 coupe use gear oil in the gearbox and EP (hypoid oil) in the differential. Separate 'chambers' with individual drain and filler plugs.
Conventional wisdom seems to discourage synthetic oils in these older gearboxes/differentials. Classic oils are available and are a closer equivalent to the originally specified oils.


Title: Re: Gear Box Oil
Post by: lancialulu on 08 May, 2017, 01:18:20 PM
Well there's the thing. I have been running 2 Fulvias used hard and covered 30,000 miles between them and both have Mobil SCH 75/90 fully synthetic oil. According to Mobil's data this oil meets both GL4 and GL5 specifications but not in the old sulphur additive way that causes problems to soft brass material.

I may be wrong but the Flavia 815 4 speed gear box is the same configuration as the Fulvia so that basis I am happy with my choice. I can only say so far my 815 Flavia has responded well to this and a thrash up the A12 to my trimmers was very quiet and coming home I noted the 1st sychro worked well and quietly....

For me fully synthetic is fill and forget.


Title: Re: Gear Box Oil
Post by: bobhenry999 on 08 May, 2017, 03:32:45 PM
Blimey, this is getting confusing !

I am about to do my annual engine oil and filter and gearbox oil change.

Normally I just use EP90 in mine as it is an early car with the gearbox and final drive sharing the oil, but Tim`s experiences of using a modern synthetic oil seems to go against the usual recommendations, yet he is very happy with how his Vignale performs with it, so now I don`t know which way to go !

Bob


Title: Re: Gear Box Oil
Post by: Angle Grinder on 08 May, 2017, 05:09:10 PM
Ditto....


Title: Re: Gear Box Oil
Post by: lancialulu on 08 May, 2017, 05:34:24 PM
Over the years oil companies have found modern additives that replace the sulphur based additive. This sulphur based additive is a problem for soft metals such as brass found in gearboxes. GL4 has a lower sulphur based additive and gives a lower extreme pressure rating than GL5. You need this pressure rating as a minimum to protect the wear surfaces in the differential. GL5 would give a better protection. Now here is the rub. The sulphur based additive combines the the phosphorous additive to form a sacrificial layer on high pressure areas such as the crown wheel in the differential. It also forms this layer on anything that is subject to pressure such as syncro rings and bronze bearings. The sacrificial layer on steel microscopically peels away as it wears, but on softer material it takes a few microns of the soft material with it over time, leading to gearbox failure, noise etc.

So there you have it. Modern oils have been developed so that gearboxes run for ever. Which would you like??

If you want to read up as I did then see

http://www.widman.biz/uploads/Transaxle_oil.pdf

Tim


Title: Re: Gear Box Oil
Post by: peterbaker on 20 March, 2019, 04:11:14 PM
Interesting: as my Flavia is very early production would I be right in assuming it has just one drain plug?


Title: Re: Gear Box Oil
Post by: lancialulu on 20 March, 2019, 06:10:02 PM
Interesting: as my Flavia is very early production would I be right in assuming it has just one drain plug?
All 815 (first series ) flavias have a single drain plug according to the parts manual...


Title: Re: Gear Box Oil
Post by: peterbaker on 21 March, 2019, 12:02:50 PM
Ta.


Title: Re: Gear Box Oil
Post by: peterbaker on 26 March, 2019, 01:30:08 PM
Well you live and learn. Flavia up on ramp this morning and discovered two drain plugs, one gearbox, and one for the diff. Refilled with synthetic GL5 .


Title: Re: Gear Box Oil
Post by: markinnes on 26 September, 2020, 04:17:02 PM
I'm convinced by Tim ref synthetic, but confused by my Flavia 2000 Coupe 1970 gearbox. Previous owner file states "gearbox replaced from Donor car" but doesn't say what donor car is. It has two drain plugs, and two filler points but with one filler point very determinedly ground off and soldered shut. Could this be because it now has shared gearbox and final drive, even if the casing looks like it was originally separate?
Any-one come across similar before?
Don't know wether to fill just with 90, or try to unplug the final drive to use 140...