5HP24 filled with red ATF - how bad?
 

Hi guys,

I realised today that at some point in the past my S8's gearbox has been filled with red ATF, rather than the proper G 052 162. I'm hoping it was the PO who claimed to have had the oil changed just before I bought it, in which case its only done 300 miles like this, but it may well have been in for longer.

Is the wrong fluid likely to have done any damage? It was behaving fine on the way home so I'm hoping a re-fill with the proper stuff and a new filter will be all it needs.

I've got 0.7L out of the torque converter, and whatever comes out of the sump (~4L from what I've read), but I think that leaves a few litres still in there somewhere. Will it drain over time with the sump off, or does it need taking apart to get it all out? Given that it was working I'm reluctant to take it to bits!

Thanks all :)

Where are you?
Mackies in Glasgow and Guy (Daviesbike on here) south of Swindon have the "sucky slurpy" machines that do a much more thorough fluid change.
You could get it trailered to one of them.

I'm in Devon so not far from Col-pax who have been mentioned in other threads on here.

The engine and gearbox are out of the car already so easy enough to take the box to a specialist for a once-over :) I'll probably pull the valve body tomorrow and see how much more I can get out.

That said, I've seen a few comments from people in the US who just run Dexron III in them as a matter of course, so maybe a few hundred miles on it won't have affected it. Fingers crossed!

So I just had a chat with Steve from Chester Automatics about getting spares for the 5HP24 and he definitely knows his subject very well. Apparently these gearboxes are fine running on red ATF (ideally Dexron VI) so that's one less thing to worry about :)

Since these things are well documented on the web and parts are easily available I'm going to open it up and have a good look at the specific problem areas with the A clutch pack while its on the bench, since I would be properly ****ed if it went bang in six months! Hopefully then I will have a healthy gearbox for at least a few years.