View Full Version : Other: Lark VI Pulley failure

09-20-2012, 07:59 PM
My 61 Lark Vi had a metallic sound form time ago

Mi mechanics told me that seems to be the water pump but still is not to be worried

I used that car for several months with that metallic sound

Today at ignition , a sound of a broken part was heard. I saw that the radiator fan pulley was working disbalanced. I stopped the engine . then I saw this strong breakage.

Can some body tell me about theprobable reason for this? I am worried to ahve the same failure again

Thanks in advance

09-20-2012, 08:49 PM
This looks like a fatigue failure. It could be as simple as a part reaching it's fatigue life. These cars were not engineered to last over 50 years. What probably happened was at sometime in the pulley's life it was left loose or was damaged in some way by a water pump failure or a careless mechanic. That damage left a stress riser or edge where flex was concentrated. This causes localized strain to exceed material strength, puts the material into yield and eventually a crack starts. The metallic clicking you heard was the crack snapping back and forth with each rotation. Eventually the crack propagated all around the part and it separated. Replace it with an undamaged part and you should be fine. If you use an electric fan and have deleted the fan blade you must use a reinforcement on the pulley face. A short fan spacer works well. Good luck. Jim

09-20-2012, 08:52 PM
One last thing. I forgot to mention to check the water pump flange for flatness and make sure there is not a sharp edge where the face meets the outside diameter. Correct defects with a flat file.


09-20-2012, 09:02 PM
Are you able to locate another pulley in Chile? I have one laying in the garage if the shipping is worth it to you.

09-21-2012, 07:20 PM
Dear friends: Thanks for the answers

JPepper. Your diagnostic make me less nervous. I fact I feel that a couple years ago, some mechanic make a strong force in the fan to move the cam . I feared that could be a general misalignement of the pulleys, or loss of center of the axis of the water pump. etc. I have looked at this axis and is firm, not loose. I will check the water pump flange after your advice.

4961Studebaker: Let me see if I found some in Chile. If not, I will be happy to accept your offer (I will pay shipping charge)

Best regards