Rocker spidle end float

[Invicta]

Hi, does anyone know the correct end float for the rocker spindle? I have two basket case model 18's, a 1949 and a 1950 that are being re built. The rocker box for one had been cleaned and reassembled by the PO and the rocker arms move , but seem a bit stiff with no percievable end float. The other rocker box was as it was taken off many years ago, all cruddy and crusty under dried on oil and some rust. The rockers were siezed solid until I losened the nuts and then they moved freely. It may have been the corrosion built up on the rocker arms that were causing the siezure. The valve side rocker arms are well worn and I want to replace them and I would like to know what the end float on the spindle should be. I am probably being a bit thick here, but looking at the set up I can not see what stops the rocker arms being clamped up soild against the spindle bush once the nuts are tightened. Also my parts book shows a ring felt for rocker axle sleeve part number 012722. Where does this fit? There is no sign of any ring felt on the rocker box that I am working on. I noticed that the rocker sleeve bushes protrude far more on the valve side. Is this where this felt is supposed to go and if so what is its purpose? Any advice would be greatly appreciated.

[PGX11]

Good morning.
On my '52 18s there are 2 rocker spindle bushes per spindle.
It appears like there is just the one long bush passing all the way through, the ends of which can be seen from both sides. In fact they are two, separated by a gap in the middle. When the rocker arms are tightened onto the spindle, the bushes are pressed towards each other into the correct position with the gap in the middle, giving no end float but not clamping the rocker arms solid. I don't know about the felt washer though. I hope this is of help.

I need some advice myself because the exhaust bush in mine seems to work it's way in by itself giving too much end float. Any advice gratefully received...
Chris Moreton

[SPRIDDLER]

Neill's workshop manual says no end float but free to move. See page 23 here: http://archives.jampot.dk/book/Workshop ... dition.pdf

The Army technical manual (page 13) says adjust end float by 'Drive left hand bush away from right to take up play'

The felt is there to wick oil onto the axles.
It's a long time since I've had to replace the bushes and then only the once but the felt was such a struggle (impossible for me) to fit that I left it out and after 25,000 miles all seems well. I've seen an article in the Technical section which describes making a mandrel of some sort to help with fitting the felt but I can't find it at the mo.

[Andy51]

Re the felt washer, no less an authority the Ken de Groome says it is not necessary. I re-assembled my '54 18S without felt washers 18 years ago and it has run perfectly since them, with no discernable wear or side play. Andy

[Invicta]

Thank you for your replies. I will leave the felt washers out if Ken De Groome says they are not necessary then that is good enough for me. I still find the design of the fixing of the rocker arms a bit strange. My parts book shows the spindle sleeve bush as one piece and lists two of them , one for inlet and one for exhaust. If they were in two sections I would have thought that they would list four of them. Clearly Chris knows what he is talking about , as unless the spindle sleeve bush was in two parts the rockers would lock up solid on tightening the nuts. I am assuming that the nuts simply tighten down until they bottom out on their thread on the rocker shaft once they have pushed the two sleeve bushes in towards each other.

[SPRIDDLER]

I am assuming that the nuts simply tighten down until they bottom out on their thread on the rocker shaft once they have pushed the two sleeve bushes in towards each other.

My memory is bit vague as I have taken arms off spindles for maybe 25 years but I'm pretty sure my '54 G3LS has four bushes. If you look at the pic of the Bush 017103 in the club spares it doesn't look long enough to fit right across both spindle posts.
The longer sleeve 017292 is shown as a sleeve rather than a bush and is long enough to fit right cross both spindle posts. Maybe the arms tighten onto the sleeve which then runs inside the bushes?

https://www.amoc-parts.com/store/comersus_listItems.asp

[Joker_Bones]

As Spriddler says...
The rocker arms on the axle clamp up against the the hollow sleeves and become one assembly.
The bushes are an interference fit in the rocker box and are positioned to just provide freedom of movement to the rocker assembly.
The felt seals fit in the bore between the bushes.
Dick Casey has a how to video on YouTube if you do decide to fit them.

[Joker_Bones]

IMG_20240102_173444.jpg

IMG_20240101_165854.jpg

Heat the rocker box around the bushes and you can fit/move the bushes with a puller or drifts. If you have to much end float you can fit shims.
I did notice that if you set the bushes to give absolutely nil end float when cold the whole rocker assembly went tight when hot.

[56G80S]

Like Spriddler, I did this job decades ago and since then there's simply been no need and no end play. I did fit the felt and can't recall how but the fact that I recall the matter probably means it was tricky. As you say, if Ken de Groome says not required, that's good enough.

I had intended doing the lightweight rocker arm mod but have shied away from it at the current time.

Johnny B

[Joker_Bones]

I had intended doing the lightweight rocker arm mod but have shied away from it at the current time.

That is what I was doing in the pics.
I saw a complete lightweight rocker box on ebay for £15. I thought it was a bargain just for the arms.
I had spare a heavyweight rocker box albeit with worn bushes and sleeves.
The lightweight box from ebay came with good bushes and sleeves so I swapped them over. The lightweight axles and therefore the sleeves are a bit longer than those for the heavyweight, so I shortened them to suit.
The idea was to have a heavyweight rocker box with the shorter lightweight arms that I could swap out for the rocker box on my G80 engine, but I haven't do so yet.
To be honest, until I saw this thread, I had forgotten all about it... I put it in a box and... out of sight out of mind.

Fitting the felts was not too bad...
As Dick Casey's video, a short tapered plug the same diameter as the sleeve is pushed through ahead of the sleeve to spread the felt out of the way. It doesn't work every time, sometimes the sleeve still traps a bit of felt in the inside bush and jams and you have to start again.