Got an 83 f250 7.5L 460 with C6 trans. My original flex plate broke where the bolts hook up to the crank. So i replaced it over the summer. Didn't drive it till we got hit with snow, figured perfect time to bring out the truck from hiding. well drove fine for 2 days then got on the freeway only doing about 45 mph and the truck just starting coasting and acted like it was in neutral no matter what gear i was in. and now the starter just spins so i suspecting that the flex plate went out again. Not 100% sure tho havent taken it apart. Any suggestions as to why the flex plate would break again if it is that.

thanks

 

Sounds like a engine to tranny alignment problem. Did you have much problem getting the tranny bolted back up the last time?

 

I don't want to alarm you, but I have heard of cases where this type of thing recurs due to worn thrust bearing inside the engine allowing the crank to "walk" back and forth.
I would first look into engine/trans alignment issues, and if that checks out, test the crank end play.
Of course, it could just have been a defective/cheap quality flexplate, or poorly fitting at the end of the crank.

 

+1 on both , either alignment or thrut issues. Also when you were bolting it back up, you should have had to "pull" the converter up to the flexplate to mate them, if not and it was a tight fit you may have other more expensive issues.

 

sorry about the late response been away from any computers. but to answer the questions the first time the transmission went up good. dont recall pulling the converter to the engine to bolt em up. may just be a motor problem plan on rebuilding it over the spring/summer so i guess ill go after those problems then. and to rogue it was a cheap flexplate just to get it back on the road.
and as always thanks

 

If the converter was not set all the way in the tranny you may of wiped out the front pump. Very common problem if your not use to setting the converters in ALL THE WAY. It should step three times going in. No front pump no go.

Craig

 

kermmydog, if the converter isnt set in all the way would it run for two full days then all the sudden go out or would it just go out. to me it should go out right away...