For the past few years weâ€™ve been telling you about how great titanium (ti) springs are, but weâ€™re getting feedback that they do not last when used in primary clutches. They are awesome in suspension applications, but feedback from the field indicates they simply do not last when placed under torsional vibration loads (as found in clutches).
The springs are wearing away the inner coils at the ends of the springs, as evidenced by a little pile of titanium dust down in the belly pans. Primary springs collapse the ends of the spring first, and due to the torsional vibration loads the springs are wearing away the coils where the contact is occurring. The wear can be witnessed on springs after only 500 miles or so. We have springs with these flat spots on the coils.
Weâ€™re told this is why none of the performance shops are using them any longer, and existing stock is being blown out at ridiculous prices. Weâ€™ve heard there may be some design changes occurring to remedy this situation, but we have no experience with the so-called revised designs. If any of these â€œnewâ€ design Ti springs remedy this situation, weâ€™ll let you know.
For now, stay with shot-peened chrome-silicon wire springs; theyâ€™re not perfect, but theyâ€™re the best proven method we currently have to work with.
Read the more recent report on this topic from the Jan/Feb 2006 issue