My 2002 truck has about 87000 miles on it and it has started jerking, the only time I notice it is when I am going up hill at around 45 and am accerating. The first time I noticed it I thought I ran over a repair line on the road only instaid of 2 thumps there was only one. And it did not happen every time.
A couple of weekends ago when returning home, we had a hilly road to travel on. I noticed it happened several times, a few of them were repeated, but not as sharp as before.
What should I be looking for?