Saturday, February 8, 2014

Changing engine and gearbox oils in Fiat Uno

It was time to do some basic maintenance things, engine oil change and gearbox oil change.
Here is the stuff used:



I used cheap 10w-40 semisynthetic motor oil. Modern oils have higher API-classes than were recommended at time when this Uno was constructed so I decided that basic semisynth is enough with API-class SL. Uno manual recommends SG-class (class added in 1989) which is now obsolete so this oil even though semisynth and by far not the best around is still better than were used in nineties. English language Wikipedia page has some good info about motor oil. Besides oil, new stock oil filter was bought. Also in pic (right) is the manual pump to add new gearbox oil.

Changing motor oil is really easy in Uno; there's not any plastic plates to remove so it's just unscrewing the bolt and hoping that oil hits the bowl in the floor. Here are tools used and old oil filter:




Uno's manual recommends oil change at every 10 000 km or once a year, service book recommends 15 000 km/once a year and repair guide gives the interval in 10 000km or half a year. This is a old engine and to save it as much as possible frequent oil changes would be good. But in the other hand this Uno won't do that much kilometers a year, so once a year I guess is mandatory and twice a year may be a bit too often. But we'll see.

GEARBOX OIL CHANGE
After engine oil was changed it was time to move on to gearbox oil. That was a bit harder. Well the "hard part" was that the draining bolt was where it should not have been at least according to guides.. Car manual shows the pictures of a older type of transmission and repair guide has pictures of yet another type of transmission. But this 1993 Uno has same 5-speed gearbox C.514 that were used in Punto and probably in at least some Bravo/Brava -models. To my knowledge C.514 was used in Uno's from year 1993 on (among others). So the draining bolt is facing rear and quite far back. Here's couple of pics:
Fiat Uno 1993 gearbox oil draining bolt location
Pic from rear to front showing gearbox oil draining bolt. Also in pic engine oil draining bolt on right.


As you can see from the upper pic there has been some leaks between gearbox and engine. Not much to do but to watch if it gets worse and then consider a bigger repair. But back to oil change. We used SAE 80W-90 API GL-4 transmission oil, this time API -class was same as the original recommendation (believe it or not but manual here is actually quite hard to understand and taking account that this has a Punto's gearbox so manual don't give exact guidance). Uno's manual states the change interval in 60 000 kilometers and Uno's service manual says 120 000km's. This is typical Fiat. Another example is fuel tank size, in the beginning of manual it says 42 litres and in the end manual gives the size of 38 litres.. I checked Punto mk1's gearbox oil recommendation and it is SAE80w GL-4 (with a change interval 120 000km's) Anyway it was about time to do this oil change, at least oil smelled bad and was very dark.

In gearbox oils you normally have to use some kind of pump to get new oil in. Front side of gearbox is a filling hole and oil level should be in a same level as holes lowest point. Here's a pic of adding new oil:
Oil to gearbox.
And there you go! These are easy to do when you can lift the car so you can work from under the car standing. While Uno was up we decided to spray some zinc-spray to fuel tank and exhaust. Fuel tank is metallic in Uno's and they are known to start leaking eventually. Goal here is to extend life of these parts, zinc is very good at stopping rust and corrosion. Or maybe I should say "slowing" instead of "stopping". Anyway, here's the picture of treated fuel tank and last muffler on exhaust. Especially muffler joints are prone to wear so we'll see how long this lasts. If you are interested about how zinc works with steel I recommend to check the "Zinc coatings -how they work" from the International zinc association.