Having got up at 6.30 this morning to take my youngest to swimming classes then dispatched the shopping and home by 11am, the sun came out and I thought it'd be a good time to tackle the ATF change. A 5 litre bottle of JWS3309 compliant ATF arrived with me earlier in the week so while the kids played/napped I broke out my long suffering Rolson 1/4" socket set and started dismantling the front of the car.

GM saw fit to equip the Lacetti with an AW LE81-40 4-speed automatic gearbox which is a bit clunky compared with the AW55 in the Saab, however it has a massive saving grace - it is fitted with both a drain plug and a dipstick, making home ATF changes a viable possibility for even a hamfisted cretin like me. To begin with, there is a large plastic undertray which covers the underside of the automatic gearbox. Its held in with 2 metal screws with 7mm heads, that screw into the trailing edge of the front bumper. Then there are 4 plastic screws which go into sort of rawlplug things which push open as you screw the screws in? they probably have a name, the idea is you poke the rawlplug thing in, then do up the screw and it pushes 4 wings out so they stay in place. Amazingly, these all came out relatively easily and while the metal screws were rusty, they were far from past it.

This is the cover I was removing. it didn't put up too much of a fight and all this was do-able without ramps or trolley jacks which made it all a great deal easier. So with this removed, the underside of the automatic gearbox was visible/accessible

The black bit is the removable sump pan. The filter lives under here, but I'm not going to touch that today, mostly because I am having huge difficulty finding someone to sell me a new one. Anyway. round the side is a 14mm hex head nut - the drain plug. Before I undid the plug, I pulled the dipstick and carefully marked the ATF level with the engine off. It has notches for 'cold' 'warm' and '80c' but all are only able to be measured with the engine running. As I'd be starting it from cold I wanted to make sure I was putting the right amount of new ATF in. I used a sharpie to draw a line across the level, about 4mm above the '80c' line

Just visible in this pic. Next, I got my 1/2" ratchet and a 14mm impact socket because my 'normal' sockets are 12-sided and I don't want to round it off. I needn't have worried, it wasn't done up very tight and soon the old ATF was flowing into my manky oil change washing up bowl

I left it to drain for 15 minutes while I went and got the new ATF and a big syringe and some clear tubing. make sure to look closely at what the manufacturer specifies for ATF. I used JWS3309 spec ATF for this job.

By this point the old ATF had finished draining and was just dripping. I did the drain plug back up (without dropping it into the washing up bowl of manky ATF, a personal first) and removed the bowl. I think its safe to say it was due some fresh ATF, wouldn't you agree?

It didn't smell burnt, but I'm 95% sure its original. Probably about due. I took this away and decanted it into my old engine oil container to be taken to the dump in due course. The manual reckons the whole system holds about 5.6 litres of ATF, but you could only expect to get about 2.2 litres out of the sump as the rest lives in the torque converter. I reckon about 2 litres came out so that's about right.

Next up, refilling. I have a load of 60ml syringes for getting engine oil out of lawnmowers, so used the same method to get new ATF into the gearbox via the dipstick hole. Its not too bad a job, the hole is probably about 1.2cm wide at the top, it might be quicker to use a small funnel and a length of hose but I'd be in big trouble if I used the kitchen funnels so opted to syringe it in instead

Lovely red fresh ATF. It took about 20 minutes syringing it out of the bottle and into the gearbox 60ml at a time, but we get there in the end. I reckoned it was about 35 syringes full to get back to the sharpie mark, but enabled me to be really precise about the level, which I'd have struggled with if I was just glugging it in via a funnel

With the level back where I started at, I replaced the dipstick, painted some copper grease onto the metal screws and reassembled the undertray bits. Looking at the super-precise level marks on the ATF bottle, I used about 2.3 litres of ATF which seems about right. With it all back together I took the car for a bit of a drive and it seems to be improved - the gearchange is less jerky and it seems to be quieter. I ran through all the ratios while I was out on my drive and it seems good for now. I plan to give it a couple of weeks of driving about then repeat the process, equating to about 75-80% fresh ATF in the box. Beyond that I'm chasing diminishing returns, and more importantly I'll need more ATF, a repeat of today's experience should pretty much finish off the remainder of the bottle I have.

All in all it was pretty painless, the gearchange is never going to be brilliant - its a bit of a slow old hector at the best of times but hopefully its a job that won't need looking at for a good while now. I'd recommend the syringe method, it takes a while but you can be really precise with the amount you're putting back in. Once I've done round 2 I'll have sorted basically all the issues I knew about when we bought the car back in the winter. Its not a bad car really.