Dommy rocker spindles wear.

Hello Robert Well this is the first sign of poor oil feed to your cylinder head rocker feed the right option you now have is to remove the cylinderand replace it with another or have the all the spindleholes milled out to have an interference fit for bronze bushing, with oil hole in it and then fit with new thackerywashers and get the oil ways blown through including the drain hole on the inlet side next to the valve springs has shown on my photo below I do hope this fixes your problem have a nice time we wish you well so good luck yours anna j

How loose is it Robert? If it is just loose enough to slide inwards and no more loose than that, you could consider a careful application of loctite with a small spacer inboard of the spindle to prevent the spindle disengaging from the end plate. If it is really floating around then boring and sleeving may be a solution.

If as Anna says the oil feed has been poor, the rocker may have seized on the spindle then the spindle will have been rotating in the head.

If a spindle say 0.002" larger in diameter will hold position then chrome plating would be another solution. I would think that your rocker would be worn large enough to deal with a spindle a couple of thou bigger

I think the loctite should be good enough to deal with a few thou. the feeler gauge is a bodge too far in my opinion.

This is a very neat solution:

https://www.rgmnorton.co.uk/buy/rocker-spindle-outer-plates-modified-to-lock-spindles_91.htm?bskt=0b619361-5858-4b16-8584-35b1b6e6b4e9

I have used the RGM modified plates, as I found that a couple of the locating tabs on the standard plates had broken off, allowing the spindles to turn. A good, if slightly pricey, solution, which should take up the end play on your spindle, provided it is not already worn.

Radial play is what you really need to deal with here and I suppose the RGM solution will do that. Worth a try with loctite first as it's easily accessible and cheap

Never had much luck with locitite on a steel part in aluminium, the bond does not last long, guessing the different expansion rates with heat break the bond after a few heat cycles. Copper plating is a lot cheaper that hard chroming and is used to recover worn bearing housings but plating the OD of the bearing, and the RGM locking plates sound good too.

Hello these Spindel locators are not going to help worn rocker spindle holes may guesstimate is the others are getting worn to it's not going to be cheap the do the right good job or find another good cylinder head So cheap fixes are Not the answer here Bit the bullet get a good long lasting job done! Yours Anna J

Robert. If you read back through the posts here you will see that I have fitted the RGM kit to my 650SS motor. It is not at all Heath Robinson, and positively prevents the spindles from turning. However it is not a cure for wear in the head, if that is what the problem is. Personally, I would try a new spindle first; you never know....

hello all, I have the same problem with my 650SS head. All 4 spindles are loose in the head but are a great fit in their respective rockers, no play at all. I was looking at the bush option but will now give the RGM fix a try as its the far cheaper option. Thanks for the tip.

Hello Well the original plates were made to do the same job but get flattened from heavy hand owners just try and take the two plate apart and push the tags of the inside plate out so they then fit right Rocker Wear Is from LACK OF LUBRICATION and block up drain ways or oil feeders tracks inside the head pipe cleaners will clean these out, disassemble the rockers and spindles and make sure you get all 8 Thackerywashers out then fit back the spindleand then get a suitabletouch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this yours anna j

Previously anna jeannette Dixon wrote:

Hello Well the original plates were made to do the same job but get flattened from heavy hand owners just try and take the two plate apart and push the tags of the inside plate out so they then fit right Rocker Wear Is from LACK OF LUBRICATION and block up drain ways or oil feeders tracks inside the head pipe cleaners will clean these out, disassemble the rockers and spindles and make sure you get all 8 Thackerywashers out then fit back the spindleand then get a suitabletouch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this yours anna j

Anna, My 57 Dommie head only has 4 Thackery washers, where do the others fit?

Previously anna jeannette Dixon wrote:

Hello Well the original plates were made to do the same job but get flattened from heavy hand owners just try and take the two plate apart and push the tags of the inside plate out so they then fit right Rocker Wear Is from LACK OF LUBRICATION and block up drain ways or oil feeders tracks inside the head pipe cleaners will clean these out, disassemble the rockers and spindles and make sure you get all 8 Thackerywashers out then fit back the spindleand then get a suitabletouch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this yours anna j

Anna, My 57 Dommie head only has 4 Thackery washers, where do the others fit?

Previously robert_tuck wrote:

The RGM kit is working well ,really easy to fit. Have not found a source for some longer whitworth end plate bolts ,I think 3/4" long would be ideal and plated or stainless . Nookys Nuts don't list them.

Hi, Robert.

I used Dave Middleton Stainless 37 years ago when I was refurbishing my 650SS, now D Middleton and Son. More recently I needed a one-off pair of studs and contacted them about providing them. They quoted from my dimensions and description and supplied following my confirmation, and, like my original experience, they were very quick. Probably not the cheapest way to source your bolts but it would provide a solution.

http://stainlessmiddleton.co.uk/

Email: sales@stainlessmiddleton.co.ukTel: 01924 470 807 Fax: 01924 470 764

This is also a good source for stainless hardware: http://www.polished-stainless.com/They also have lots of BSC ?"

Fritz

When I got my bike, a previous owner had bushed the rocker spindle bores on my Dominator head, because the rocker spindle bosses in the head were badly flogged out. Unfortunately, the spindles were a loose sliding fit in these bronze bushes. After consideration, I got the spindles hard chromed and ground. The grinder was not accurate enough, and couldn't make them the size I wanted - they should be 0.001" to 0.0015" interference fit

After a lot of messing around, I found that the spindles could be matched to a rocker, and give a just acceptable sliding fit. More messing about, and a friend with a lathe polished each spindle end so that it was an exact fit in the respective bush in the head.

This was a very prolonged solution to the problems in my head. It might have been cheaper and quicker just to find another head.... But it's fixed now. When the bike is run in, I will know whether it really is sorted.

Paul

Previously robert_tuck wrote:

One of my inlet spindles is loose in the head and is set further in so does not engage well with the plate. What is the normal fix for wear in the head bore?.

Bear it in mind that the rockers are hardened steel, so if you want to enlarge the bores, they will have to be ground or honed. Given that your bike is a '50s machine, you will either have to get a spiral groove cut in the spindles, or upgrade the whole lubrication system to '60s spec with 6-start worm gears, and open out all the oil ways in the cases and cover.

My machine had an oil feed taken from the timing cover to the rockers, for increased oil feed upstairs (remember, lack of oil is the cause of the rocker bores flogging out...). That meant too much oil up stairs, and a loss of oil pressure to the big ends. The over-feed to the valve gear was dealt with by fitting oil seals on the valve guides, which then had too little, and they became sticky.

Hey ho. My solution was to follow a recommendation from Norton - if your valve gear is not getting enough oil, fit the oil tank union from a 250 or 350 unit twin, which is almost the same, but with a smaller through-drilling. (Actually, what I did was make a disc with the right hole size drilled in it, and silver-solder that to my oil tank union). That forces more of the oil returning to the tank to the valve gear. Next time I run the bike, I will take valve covers off and see if I get sprayed with oil....

Paul

Previously robert_tuck wrote:

Thats very interesting Paul, sounds like I dodged a bullet there. Seems like the best all round solution would be for someone to supply a set of oversize and a tad longer spindles and have it all bored out to suit.