I know there has been other forums on transmission problems but i cant seem to find anything on the problem im having. I have a 2010 fx4 but i drive it about once a week or so and when ever i first start it up after its been sitting for a while i always let it run a few minutes no matter the temp but the first shift from park to reverse the tranny always thumps. It only started doing this after i pulled my friends stuck chevy outta the mud. The truck had about 1700km(1056miles) on it at the time and now has a little over 16000km(10000miles). Even if i let the truck run till all the gauges are at normal temp it still does it. Did i cause this problem by going from drive to reverse and back to drive ect. while pulling out my friends truck?? Or is this just from letting the truck sit for a while cause usually if i drive the truck everyday it doesnt seem to thump, or thump as bad?? Any imput would be nice, and thanks in advance.

 

Is the truck parked on an incline when you shift from P to D? If so, try using the parking brake the next time you park there before you put it in P.