I changed my spark plugs on Friday and it made a world of difference. My truck has about 76k on it and I never realized how bad it was running. Now with the new plugs and wires in it runs smoother, doesnt shake as much, and eliminated the hard shift I had between 1st and 2nd gear. I don't know how it helped the hard shift but it did. Since my truck has had tranny problems and it was rebuilt once I figured the shifting was due to the dying tranny. Anyone have an explanation for why its better now? I compared the spark plugs to the pictures in the haynes manual and they were all just normal wear.

 

Did you gap the plugs to see how wide the old ones were? At 76,000 miles one side was probably .070 and the other side at .080 or more. It's too wide to consistently get a spark across the gap.

Doesn't matter what the handbook says, change them at 50,000. At a minimum regap them.

 

No i didnt check the gap on the old ones altough i am sure they were close to that. I knew that my truck was overdue for plugs but I just hadnt had the time to change them.