Hi all,
I have a noise in the rear end and suspect the diff is out of oil.
I've never even inspected the diff oil before.
Do I use ordinary engine oil ? and how do you fill it ?
Do I need any special tools ?
It's a standard open 120y sedan bw diff.
It's just a daily driver .
Cheers

Who inspects the diff oil??? It,s out the back under the car out of sight!!! Ok DON,T use engine oil, use 85-140 diff oil u can buy it at superjunk, autowank, maybe even your local petrol station has some hidden behind the dogfood,and mars bars!!! Your diff will have a bung or large nut on the back plate, undo that and try to get a pinkie in there {or a piece of bent wire} dip it in to get a reading of how much oil is in there.. If nothing, damage is done, fill it up till it starts to overflow that hole.. Might last a bit longer!! Yes its a fun job getting oil into diffs, buy a squeezy bottle F.T.W..Makes it easier.. If oil already in there, diff is just worn out and you will need to replace it anyway.. Note if diff is oily and greasy that oil u just put in will leak out again so you,ll need to keep an eye on it!! Or replace the front seal... Another fun job!! Cheers Steve

Oils aint Oils Shirley !! You are best to use diff Oil. you can find the type of oil in a datsun manual, or some people will now off by heart. This also goes for how much you will need to do the job. The diff centre will have a plug that gives you access.

With that being your prob, check if the diff is leaking.
I use to have a rule with datsun's if the diff centre comes out it only goes back in LOCKED

Good luck i hope it only a small prob.

If it's making noise, then I suspect there is some damage or wear going on already. Adding oil may stop it from getting worse, but won't fix the problem.

It could be a wheel bearing, ring and pinion wear, or possibly some bearings in the diff that are the culprits.

By all means check the fluid, but I would recommend jacking the rear of the car up and spin each wheel to see if the bearings are the cause of the noise. When they start going south, it's pretty obvious with the spin check.

I speak with some experience as I have recently replaced my rear wheel bearings, and just had my diff rebuilt.

They replaced mine with standard gearbox oil.

Do I need to change it again?

Thanks. I'll get on to it.
I think I'll do the spin test first.
I'm hoping it's only easy bearings.

1200gxman--- Gearbox oil is the same as diff oil so it,s all good... Also good advice on the spin test!!!

Easiest way to get diff oil in is get some long heater hose with a 1lt coke bottle on the end (1200 diffs only take around a litre) and poke it through the big rubber plug in the tyre well and into the back of the diff and fill her up. Thats on a 1200 anyway not sure if 120y would be similar.

Yes on the sedan you could do that I might do that this week if i get time

Quote:

I don't know. I talked a few minutes ago to a oil shop that only sells oil. (Fuchs oil).
The guy said that gearbox must be EP90 GL-4 and the diff oil must be 85W 140.
There is apparently a difference between GL-4 and GL-5.

I will rather change it. Luckily only a weekend car and did'nt do much km after the diff and oil change. I think about 9000km.