Club 80-90 Forums

Hi All,

Does anyone have a list of recommended oils, lubricants & capacities to be used for the Syncro? I've heard it said that the oil for the front & rear diff's is very specific. Is this correct.?

Please help before I stick in the wrong stuff and blow them to bits!

GL4 spec for the gearbox
can be run in front diff too, but front diff can run GL5
some GL5 have addative in which can damage our synchro rings hence we use GL4
I recommend Fuchs Titan Gearsyn 75W/90 from GSF 98048A 4 litres 98048 1 litre
semisynthetic oil use front and rear
4.5 litres rear 1.5 litres front
Millers do similar lube twice the price, Redline twice the price again, most blenders will do something similar but it must comply with GL4 , most will be both GL4and5 compatabile like the Fuchs; Fully synthetic oil will only be £1/litre more expensive
20k miles/3 years/more often if driven hard/syncro/hot climes

http://www.castrol.com/castrol/iframe.d ... Id=7044829" onclick="window.open(this.href);return false;

http://www.castrol.com/castrol/iframe.d ... Id=7044829

they have the volumes wrong on the gear oil on their site it says 3 litre for 2.1 syncro and lumped in with 2wd in age too 1979-

That's what's in my front diff (after changing the visco)

Castrol TAF-X
Fully synthetic SAE 75W-90 multi-grade transaxle oil. Designed to help improve cold weather gear selection and keep transmission noise levels to a minimum at high operating temperatures.
Recommended where an API GL4 lubricant is specified

comes highly recommended by the German Syncro specialist forum

Has anyone tried out any of those additives you can get for gear oil?

Everytime i go into my local autofactors they have this little gimmicky toy you can wind the handle round on. It turns some cogs, the bottom one of which turns in a bath of oil.

One side is (supposedly) normal gear oil

The other side has the 'additive' and on this side the oil gets picked up by the cogs and makes its way all the way to the top cogs. Whereas the one without additive the oil only makes it as far as the second cog.

Visually it makes sense, the oil gets pulled to all the places its needed, but is there actually any science or truth behind it? What's your thoughts Aidan?

cleaning a box that's had molyslip in is a pain, but it probably helps,and I've used it myself previously; trouble is thing is normally added to box that's already a bit noisy instead of fixing it then, by time I get it it's foobarred but I have to clean it all up to see what can be salvaged, but it definately coats the surfaces of metal with a useful coating that holds oil and includes moly which is the friction coating used on our synchros anyway
other addatives I know not of
regular oil changes got to be better than any additive, so if additive is £10 and gear oil is £20 change the oil more often rather than half as frequently as you probably would with the additive in, so effectively twice as often, new oil is good lubricant and has useful additives anyway and changing it removes contaminants which make a grinding paste and regular observation of wear fines on plug will guide to timely and more economic reconditioning

That Castrol sounds just the job and interesting to know what other forums use

The Fuchs being available through GSF is readily available with a club discount to most peeps on here and is good value for money ime but there are many other similar and probably better lubes too; I figure if it's £20 then people will be happier to change it than recommending Redline and peeps finding out it's £90 and keeping it in there for 5 years cos they don't want to shell out another £90

Engine oil change is nearly £20 oil and filter and we all do that twice a year, gear oil change once a year wouldn't break the bank

I ran the issue of diff oils past my oil supplier (Esso/Mobil) locally, giving him all the info you guys had posted. He then spoke with a lubricants expert within the company and he replied as follows:

Your customer is correct in mentioning that if a GL5 is used when a GL4 is specified there is a danger of plating on syncros and making gear changes difficult.

Mobil do a similar product to the competitor oils mentions and this is Mobilube 1 SHC 75w-90 which covers GL4 and GL5 without causing the problems mentioned above and is fully synthetic and therefore carries a higher price tag.

If price is the stumbling block and GL4 is preferred spec then Mobilube GX80w-90 mineral oil can do the job in my opinion.

Hope this info is of some help. I've got 20ltrs of the synthetic oil on its way and I'll let you know if I have any problems with it.

Forgot to mention something in my last post!

Just an idea but.... perhaps on the Syncro wiki page there could be put up a recommended lubricants and quantities listing. This could also included a list of manufacturers and the oils they supply.

standard mineral oil GL4 is absolutely fine, but getting harder to find generally , most places now just carry a GL5 80w/90
but the semisyn is pennies more expensive and gives a better change when cold being less slugglish to get out of the way when making that first 1st to 2nd change of the day; fully syn gives even easier shift so you should enjoy the change

this may sound silly but are there any advantages of using a mineral oil? eather in a gearbox, front diff, or an engine?

neil

advantage is cost spec and ready availibility for engine and since ours were designed to run on it works well, whereas your mobil1 etc not really suitable and synth 15w/40 expensive so regular frequent even oil change with mineral oil works well for engine for me with wbx