T3 oil change

I’m asking after the event I know, but I have just changed the engine oil and filter on my T3. I have put in 3L of agip 20w/50, then I looked in my Haynes manual and it specifies agip 10w/50. Am I ok? . Also I have a gift for stripping bolts, so after looking  up torque settings online I have tightened the 5mm sump bolts up to 1kg / 10 nm . This feels not much more than finger tight to me, certainly a lot looser than when they were undone. The drain plug is tightened to 5kg / 50nm.  Any thoughts would be appreciated. Cheers Dougie.Â

Motor’s not brand new (i.e tight), so while it’s Summer at least should be OK I would think. I’ve started using 20/50 in my 850, no probs at all.

I think you’ll be fine. The 50 is the viscosity when hot, so that’s the bit to get right. I use synthetic 0W-50 in my loop.


I use Agip 20 / 50 mineral oil in my T3 and its fine. It seems to run better with mineral oil than part synthetic, perhaps because the engine was designed round that at the time.  Whatever, new oil is better than old oil.Â

As for torque setting I have never bothered except inside the engine.
If the sump soesn’t leak and the screws stay in place then they’re tight enough.

Just stuck 15/40 in mine - found a tin of it lying around in the garage. I think 20/50 is listed somewhere as an alternative, which will be a little thicker and as Ian notes shouldn’t worry at this time of year, if at all.

I always pull mine down by feel, just tight enough - but I’ve no clue what numbers that would be.

I found a torque setting chart on a web site called thisoldtractor .I’m going to check the sump bolts after the next few rides and if they don’t loosen will keep referring to it. Especially the next job of front wheel out for a new tyre.

Remember that they screw into alloy, too much welly may damage the threads, so I’d go with what Ian said. Tighten by ‘feel’ with an Allen key.

Only times I’ve ever used a torque wrench on mine is for the cylinder head nuts.

How do you explain “just nip them up” to a modern apprentice?

I consider myself a 55 year old apprentice, that’s why my questions may appear too basic to some , but I am taking it all in and hopefully learning. Good of everyone to chip in with their opinions. I always feel the need for one more nip, that’s why I’m using a torque wrench.

Re last 2 posts.
I did mention to HNH that a series of very basic servicing articles would be valuable.

It would for me, I want to attempt several jobs this winter, check points, bleed brakes, clean the carbs etc. I’m going to have a go but my Haynes manual won’t be enough.

I was faced with this challenge when my younger daughter was showing interest in the garage - for her Scouts mechanics badge; I made sure she did that properly. On tightening something down she was asking how tight and I said ‘just tight enough’. Which immediately struck me as a completely worthless comment. How can we know? I guess over long years you just get a feel for what is going to be right for the materials involved. Maybe you have to get it wrong a few times before you know, maybe some of us are just blessed with a better touch? Best I could do was tighten it how I wanted it and then she had a try at backing it off again to get some idea of pressure.

Mind you, new plugs with their crush washers are always a worry.

True! That’s deffo something you need to learn the feel for.

My rough rule of thumb is if I’m exclaiming ‘Jeezuz effing aitch chroist!’ or similar when I’m trying to unscrew something, it was possibly done up too tight…

The previous owner of my 850 seemed to have been like that and the final drive and gearbox drain plugs threads (for example) were overstressed. F/D thread finally disintegrated and needed an insert repair.

My R80 must have been given to apprentices to practice on at the end of its Police service ~ the heads and rocker covers were in a terrible state… there’s a big M8 stud in the centre of the head that mainly holds on the cover, both sides had been ripped out the heads, helicoiled, then the helicoils ripped out!

According to the Guzzi workshop manual, M6 bolts like sump bolts should be tightened to 0.8-1.2 kgm which I workedout as being 11NM so you’re not far out with 10.

As a general rule, I think the use of copper grease helps, by providing some consistency in the feel and level of resistance when tightening bolts and nuts, especially with new plugs with crush washers.

As an apprentice diesel fitter i was told tighten it up till it goes bang and back it off a bit! It takes a lot of bangs and oh sh1ts to learn the value of a “speaking spanner”/ torque wrench and the right settings!

Well there is a small puddle under my oil drain plug this morning so I shall re tighten a tad more.
Probably should change the washer next time.

What I do with my apprentices on our aircraft is to make them use a torque wrench all the time until they’ve worked out how little you actually need to tighten bolts up. I’m still amazed from time to time when I go to undo an oil filter and it’s done up to feck me tight instead of 25 lb in.

Tightening something too tight can result in a small involuntary emission of wind.