5 replies to this topic

[wile e coyote]

Just reading another thread and the importance of keeping pushrods in order on removal and refitting came up - have always wondered why?

 

I've measured the ball diameter of a selection of varying mileages / ages - all very uniform and all nicely evenly rounded too......

 

It's about the only piece of accepted wisdom I've never quite understood - whenever changing head gasket etc I always do it because Haynes & everyone else seems to say so - but if putting in new followers I don't bother just check them over clean them up replace any with any evident damage or slightly out of true from my spares stash and pop them back in randomly......never had a problem......am I doing it wrong??????????

[100ev8]

just good practice if using all the old components you stripped out 

[mini danny]

I believe the push rods "wear" to the cam followers and each push rod and cam follower will wear slightly diffrent to the next. So changing the order of then will cause them to wear differently again which will cause the clearances on the rocker tip to alter.

I may be wrong will soob find out

[myredmini]

They all wear to each other so always best to fit in the original sequence so they don't need to "bed in" to the different surface.

[Dan]

......am I doing it wrong??????????

Well no. When refitting all used components they will be matched as sets (the complete train of parts from the cam onwards for each valve) because they are worn into each other. Each set will look broadly similar but a close inspection and measurement would show differences. Once you change something though, such as fitting new followers, all that is forgotten and you are starting again. If you do fit new parts, or do get them mixed up, all it means is a little running in and the clearances opening up more rapidly as the parts bed into each other from scratch. They will soon settle back to a state of being worn in and the clearances will stabilise again. It's good practise to keep them together, due to this slightly increased wear when they are bedding in, because the surface hardening isn't all that thick on some parts and if you swap bits around a lot (if you go through a lot of head gaskets for example) the extra wear could go right through.

Edited by Dan, 30 December 2013 - 11:47 PM.

[wile e coyote]

Yep that makes perfect sense - minor OCD annoyance sorted!