i oun a ford pickup with a 302 , automatic. it runs fine but semms like it missing, i get a vibration when i drive in the high gear. when i first take off and give it gas it runs fine( under load) soon as it goes in the high gear i gert the vibration and worse if i give it allittle gas,( in the high gear) soon as i let up on the pedel it run smooth, push down on the pedel and vibration. what up with this!!

 

i had an '83 f150 302/aod and replaced the engine with an older 302 block. i had a horrible vibration. can't remember if it was high gear or not. come to find out i had the wrong harmonic balancer and crankshaft combination. the only solution i could come up with was replace the rebuilt engine's crankshaft with my old one and also use my old harmonic balancer. unfortunately the crankshaft did not have a flange on the rear main and i lost oil continously. least to say i bought a fred jones short block shortly thereafter. hope this will help some.

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Scott
88 xlt 302efi/aod

 

Check your u-joints&,harmonic balancer. Could be a trans problem tho. good luck