Checking the rear differential oil level and filling it up

I’d have to check my rear differential oil level often – because it leaked – and top it up when needed. It’s simple to do but If I had ignored it a gear rebuild or new differential would probably be costly.

I showed you how I fixed the leak (here), now I’ll show you how to fill it up and check the level.

1. Remove oil plug – somewhere on the rear differential casing

This will be different on different vans but the plug is usually a round bolt with a square in the middle – it’s unscrewed with the box end of a ratchet. There is a magnet on the end of this bolt that catches little bits of iron and it’s normal to have some bits on there – you can remove them if you want.

2. Check level

The level should be right up to the filler hole (where the plug goes). You can just put your finger in and if you get oil on it then it’s all good. If you can see any oil or cant feel the oil then it’s worth filling it up.

3. Get the right oil

This depends on you vehicle but my LDV Convoy needs GL-5 spec grade 90 gear oil. The right oil to use is always in the manual, probably at the beginning.

4. Fill

This is probably one of the more awkward things to fill on my van. I put a bit of flexible pipe on the end of a funnel. I filled it until the oil started to spill out of the filler hole. I put back the plug, making sure to not over tighten.

That’s it!