Worn rocker shaft

[Tim T]

For sometime now I have had very noisy tappets and despite resetting them on many occasions can't shut them up.

Having read a few topics on the forum I was pointed in the direction of the rocker shaft. So I have bought a new one from Moss and today removed the old one - I think that I may have found the problem - see image below! The wear is about 0.3mm!

The Moss replacement unit has a thread inside each end of the shaft with a grub screw fitted inside. The old shaft was just a plain tube.

My question is why are these screws there, do I leave them in and if so is it wise to Loctite them in?

I will obviously be refitting the old end caps onto the shaft.

Many thanks again,

Tim

 

[Motorsport Mickey]

Yes, clean the threads in the shaft and on the grub screw with thinners and allow to dry after blowing off then loctite the screws into the ends taking care not to block any oil ways that may be there, if none are visible great.

 

Mick Richards

[Tim T]

Thanks Mick. Shaft was pretty bad?

Tim

[Motorsport Mickey]

Pretty typical Tim, these engines are "hewn from granite" and they'll continue to run even as they become steadily less quiet, or effective. A great car and engine to use as your daily car, they'll continue to work and back whilst you define what the problem is and then fix it outside at the road. Enough of us have done that over the years.

 

Mick Richards

[Tim T]

Another couple of questions regarding refitting.

Should I replace the bearings inside the rockers arms as a matter of course - there is a small amount of play when on the new shaft but minimal?

The pedestals are alloy and the new shaft is very tight in the pedestal ie it will need 'persuasion' to fit and therefore mark the inner housing or do I ream them out to a snug fit?

Thanks again,

Tim

[Motorsport Mickey]

Dropping the pedestals in a pan of boiling water for a couple of minutes normally expands them enough to fit without work. If you fit a new shaft fit new bearings the to the rocker ams, there will be crud and old rocker shaft material suspended in the bearings which does a nice job of chewing up the new rocker shaft reducing it's life.

 

Mick Richards

[Tim T]

Mick, job done - many thanks for advice. Went for a drive today and now sounds like a different car.

Tim