View Full Version : Automatic transmission GMC Safari

05-05-2012, 03:19 PM
When shifting between 1st and 2nd, a noticeable speed surge; between 2nd and 3rd, a fairly loud clunk - any ideas?

05-05-2012, 09:19 PM
2 to 3 could be a shift spring if you're lucky, the 1 to 2 sounds like clutch slip. Have you changed the fluid? I had a broken spring in my 4L60E around 230k, changed it and went to 400k before I rebuilt it. I change the fluid every 30k miles though too.