A few weeks ago I had the auto transmission fluid in my Series III 380 changed as part of the 90K service. Since then the gear changing at lower speeds (up to 60 kph) has become somewhat erratic with lags between changes and the car sometimes appearing to "search" for the correct gear. At higher speeds (above 80 kph) it seems okay. I've checked the fluid level and it appears to be correct.

Any ideas? Presumably the problems are related to the fluid change as it was okay before that. I also had the timing belt, water pump and back 3 spark plugs replaced at the same time.

Thanks

A few weeks ago I had the auto transmission fluid in my Series III 380 changed as part of the 90K service. Since then the gear changing at lower speeds (up to 60 kph) has become somewhat erratic with lags between changes and the car sometimes appearing to "search" for the correct gear. At higher speeds (above 80 kph) it seems okay. I've checked the fluid level and it appears to be correct.

Any ideas? Presumably the problems are related to the fluid change as it was okay before that. I also had the timing belt, water pump and back 3 spark plugs replaced at the same time.

Thanks
Did you get it serviced at Mitsubishi or an independent? Sounds like they may have used the wrong transmission fluid.

At an independent. The local Mitsubishi dealer had a 6 - 8 weeks wait for appointments and I wanted to get the work done before undertaking a long interstate trip.

My money is also on wrong fluid.

Take it back and tell them it's no good. If you provide genuine fluid from a dealership they should do the flush and replace the fluid for free.

These boxes don't seem to like anything other than genuine fluid. Even fluids which purportedly meet the SP3 specification often give grief.

Most independents would not know this. They'd simply use the cheapest fluid which supposedly meets the spec.

Thanks for your replies. Next question: We'll be driving home to Canberra from Adelaide on the weekend and assuming the problem is the incorrect fluid, will this cause any damage to the transmission or should I try to get it sorted before the drive? Of course, I've already driven from Canberra to Adelaide so the damage may already be done!

Further to my earlier posts, I phoned the mechanic who changed the fluid and he advised that he used Penrite ATF MHP semi-synthetic fluid which apparently exceeds Mitsubishi SP3 specifications. So no idea why the gear changing has become erratic but presumably the car will be okay to drive back to Canberra where I can get it checked out further.

In the last two ATF fluid changes I've had, SP-III compatible non-genuine fluid was used. 196k it was filled with Hi-Tec Oils Multitrans ATF Synthetic, and 247k it was filled with Penrite MHP Semi-Synthetic. Now that its at 267k, I have had no issues with either.
Many will bring out the torches at the suggestion of aftermarket ATF, but as long as its a reputable brand and specifically says that it is SP-III compatible, I don't see the issue. (Yes, I also understand that genuine fluid can be bought at a similar price, but its not always practical to supply your own (eg. some workshops will not use supplied parts/oils))

Have you disconnected/replaced the battery lately?

No, not since October 2013.