Rocker spindles

MikeG · Feb 25, 2017

Thanks to all who took the time to answer my questions in the rocker oil feed line thread. I decided to pull the spindles drill them and run an oil pressure gauge off the left side banjo. Made a simple puller from threaded rod and a short piece of 1inch PVC pipe, walked the spindle out slowly and collected the spring and washer no problem. Now I find that the spindles are worn to the point I can see gouges and feel a ridge between where the rocker arm was riding and where it was not. The wear is mostly on the lower side of the spindle. Are these normal wear patterns, and what kind of mileage might it take to cause it? I bought this bike running and have never had to go any further in that the timing cover.

CanukNortonNut · Feb 25, 2017

MikeG said:
Now I find that the spindles are worn to the point I can see gouges and feel a ridge between where the rocker arm was riding and where it was not. The wear is mostly on the lower side of the spindle. Are these normal wear patterns, and what kind of mileage might it take to cause it? I bought this bike running and have never had to go any further in that the timing cover.

MikeG,
A picture to show would be good, but if you can feel the ridge with your fingernail then I would say it should be replaced. Are all the spindles in this condition as you state? All worn would probably mean no oil to the head at some point in your bikes past or some abrasive foreign material left in the oil system, Inadequate oil changes, etc. What is the condition of your rocker bores? Does your bike have an oil filter on your 71 Commando? If not maybe it is time to fit one. :idea:
Cheers,
Thomas

Danno · Feb 25, 2017

Better check the supply to the line. the only one I ever saw with galled and scored rocker bores and shafts had zero oil supply for long enough to ruin everything.

Stephen Hill · Feb 25, 2017

Could you measure the diameter of the worn section vs the unworn section and post the results?

Stephen Hill

MikeG · Feb 25, 2017

Have only pulled one so far, plan to pull the other intake tomorrow. The rocker bore looks good but I have not measured yet. The oil lines were clear, but they looked to be fairly new when I bought the bike so?? It had no filter when I got it, added one right away and have run Valvolene VR 50wt. I'm surprised at the wear pattern more than the fact they are worn. I would think the majority of it would be across the top and closer to the valve rather than on the bottom.

MikeG · Feb 25, 2017

Stephen Hill said:
Could you measure the diameter of the worn section vs the unworn section and post the results?

Stephen Hill

I will tomorrow, and post pictures as well.

Stephen Hill · Feb 25, 2017

The wear is on the bottom of the spindle because the pushrod pushes the rocker against the spindle, resisted by the spring pressure on the valve.

Stephen Hill

MikeG · Feb 26, 2017

Update with pictures. Spindles measure .049 on the part the rocker was not riding on and about .0485 to .0480 where it was. The plain washer on the left side show evidence of excessive play. The rockers measure .052 ID and look OK

APRRSV · Feb 26, 2017

Hi Mike,
It looks like you have the decimal points out of place. In any event, the manual calls for about 0.001 to 0.0015 clearance between spindle and rocker bore.

Ed

gjr · Feb 26, 2017

There was a time when Norton's metallurgy was not 100%, see the three lobed cam out of my '70, so it is not too surprising that the rocker shafts could be worn. Andover Norton has spindles for ~£13 each and rockers for ~£93 each. I'm sure Old Britts or CNW has the parts in stock. The cost of the rockers would have me thinking about getting them bored and sleeves installed.

Greg

MikeG · Feb 26, 2017

gjr said:
There was a time when Norton's metallurgy was not 100%, see the three lobed cam out of my '70, so it is not too surprising that the rocker shafts could be worn. Andover Norton has spindles for ~£13 each and rockers for ~£93 each. I'm sure Old Britts or CNW has the parts in stock. The cost of the rockers would have me thinking about getting them bored and sleeves installed.

Greg

Boring them and fitting a bronze bush sounds interesting.....

MikeG · Feb 26, 2017

APRRSV said:
Hi Mike,
It looks like you have the decimal points out of place. In any event, the manual calls for about 0.001 to 0.0015 clearance between spindle and rocker bore.

Ed

Yup..one place to the left then

CanukNortonNut · Feb 26, 2017

MikeG,
Looking at that shaft, I'd say replace it. How are the others? If you don't know this engines secrets I would pull the rest for a look see. As a matter of what I have seen so far, I would do a full engine inspection. But that's just me.
IMHO
Cheers,
Thomas

kerinorton · Feb 28, 2017

That wear is pretty common on all older British cars that have done a few miles. You could probably get away with fitting new shafts. Most of us would probably be riding trouble free with our bikes and have worn rocker shafts like that. I f it wasn't noisy before you took it apart, why fix it. If every time we found a rocker shaft on a car that was worn like that and told the customers they needed new ones, they would have a fit. But on the other hand, if you have money to burn, burn it, and give double the amount to the blind and hungry as well.
Just my 2d worth.
Dereck

concours · Feb 28, 2017

kerinorton said:
That wear is pretty common on all older British cars that have done a few miles. You could probably get away with fitting new shafts. Most of us would probably be riding trouble free with our bikes and have worn rocker shafts like that. I f it wasn't noisy before you took it apart, why fix it. If every time we found a rocker shaft on a car that was worn like that and told the customers they needed new ones, they would have a fit. But on the other hand, if you have money to burn, burn it, and give double the amount to the blind and hungry as well.
Just my 2d worth.
Dereck

+1
Also, invest in IPA's :mrgreen:

dynodave · Feb 28, 2017

Re: oiling puzzlement?

These days I do follow threads with issues related to lubrication. Whether for the cranks or the high pressure or return line puke pressure rocker feeds.
After the oil pump testing and research I have done, I am amazed at the low regard that norton owners place on knowing if they have adequate lubrication. (5psi warning light...really :roll: )
The number of nortons I have been involved with including the used relatively low mileaged NHT I now own, the resulting condition of the oiled components is abysmal. Lots of ugly rocker shafts and crankshafts.
Early low pressure scrolled rocker feeds is a known marginal system resulting in 6 start oil pumps as a first attempt for improvement.
hot rod cams, stiff valve springs, braided stainless lines and ricky racer 7000 rpm mods VS anti wet sump valves?
Wish I knew which oil pumps are the good ones. Like NENO member Jeff S. 170,000 on his original MKIII crank, while a lot of my older very low mileage bikes all need engine rebuilds for bad cranks, or in every case did the PO run them without oil???
Until my research is done ...every NHT I own and run will get an oil pressure gauge and will be monitored closely.

texasSlick · Feb 28, 2017

At ~£13 each for spindles, it is cost effective to buy new, but an option is to have your old ones nickel plated, then ground to size. The cost of plating and machining may be greater, but the spindles will then outwear four engines.

At ~£93 each for rockers, bore and press fit a bronze bush is the way to go. Use a thin walled bush to keep metal removal of the bore to a minimum.

Slick

kerinorton · Feb 28, 2017

concours. Who told you I drink IPA's. Boundary Rd Mumbo Jumbo is my favourite and our hon pres's favourite as well. Not sure it Tim was introduced to it though.

And that is a sound investment.

Dereck

JimNH · Mar 1, 2017

Re: oiling puzzlement?

dynodave said:
These days I do follow threads with issues related to lubrication. Whether for the cranks or the high pressure or return line puke pressure rocker feeds.
After the oil pump testing and research I have done, I am amazed at the low regard that norton owners place on knowing if they have adequate lubrication. (5psi warning light...really :roll: )
.

I have an oil pressure gauge. When the timing cover conical seal split the pressure immediately dropped from the 45-50psi +/- to around 15 or so while riding, much lower when idling. A 5psi warning light would have caught my attention at the stop light. My reaction, however, would have been to check the oil and finding the level ok, then checking that oil was returning, which it would have been doing. So I'd have been thinking maybe everything is ok. I'm totally in the oil pressure gauge camp.

MikeG · Mar 1, 2017

Re: oiling puzzlement?

JimNH said:
dynodave said:

These days I do follow threads with issues related to lubrication. Whether for the cranks or the high pressure or return line puke pressure rocker feeds.
After the oil pump testing and research I have done, I am amazed at the low regard that norton owners place on knowing if they have adequate lubrication. (5psi warning light...really :roll: )
.

Click to expand...

I have an oil pressure gauge. When the timing cover conical seal split the pressure immediately dropped from the 45-50psi +/- to around 15 or so while riding, much lower when idling. A 5psi warning light would have caught my attention at the stop light. My reaction, however, would have been to check the oil and finding the level ok, then checking that oil was returning, which it would have been doing. So I'd have been thinking maybe everything is ok. I'm totally in the oil pressure gauge camp.

I plan on having both.

Rocker spindles

Similar threads