Mechanics

FLEXPLATE-SHEARING FAILURE AT BOLTS

1994 Ford Aerostar

Transmission problem
1994 Ford Aerostar 6 cyl Two Wheel Drive 177000 miles

I recently had the 4 speed stock transmission overhauled by a mechanic who has experience in this type of repairs. We both installed it with a kragen -remanufactured Flex plate and rebuilt torque convertor. It ran well and shifted very well for about six months and then while going up a small grade it broke down. I took off the transmission and the problem was the flex plate sheared at the bolts next to where it attaches to a small spacer and hub on the crankshft. The pilot bearing and hub is not worn out as it fits the torque convertor very snug.
However when I first installed the transmission, I did notice a very slight vibration when filling it up with oil at idle speed. Why does the flex plate shear? Do I need to use FORD original equipment parts for the flex plate and Torque convertors? What do I need to do to solve this problem?
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Daniel Chapa
November 2, 2009.




Actually, this doesn't happen often. However, it is usually the result of a factory crack that was in the flex plate prior to you getting it. There shouldn't be a need to have a factory part.



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