Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board rocker shaft spring washer location??

On unit twin Triumphs there are two flat washers and one spring washer for each rocker arm. The Haynes manual shows them located one way and the parts book shows them a different way. Shouldn't the spring washer face outboard against the rocker box housing with the flat washer against the rocker arm?

Depends on which rockers you have, drilled rockers its spring to rocker, slotted its thrustwasher to rocker but make sure rockershaft was a flat or a spiral groove or the oil never gets to the slots .

Thanks kommando. I have the slotted rocker arms with plain rockershaft, no scrolling. Do you know when Triumph made this change?

Very late 60's early 70's. You can get later T140 rocker shafts with the spiral groove or stone a flat or mill a slot in your current ones.

Hi Kommando,
When you put your groove in the spindle did you put it in line with the oil holes and when you fitted it did you put the groove up or down and why. I have read that the grove should go at the top but it seems more logical to put it at the bottom to help flow.
Thanks again

I followed John Healy, groove to top.

I am sure John is right but why is the groove better at the top ?

Because oil is heavier than air so by starting at the top it goes down and hope fully goes where it should and not exit before it has a chance to go up. What makes you think putting at the bottom improves flow, I can't think of a reason as flow is regulated by the gap, the bigger the gap the better the flow. I tested it with lightly pressured oil and it all got to the right places.

I'm working on a 1970 Bonneville rocker box now. It has a spiral groove cut into the rocker shaft. The flat washer on the side nearest the oil line feed has a much smaller inside diameter than the other 3 flat washers. Therefor it is impossible to put that flat washer against the rocker arm because the shaft can't pass through it. The only choice I have is to put the Thackery spring washers against the rocker arm. I believe this to be incorrect and perhaps this thing was put together wrong at the factory.

Yes the factory fitted the wrong parts in the wrong place, you need per rockerbox 4 1/2" ID thrust washers and 2 spring washers, the 3/8" ID washers go into the spares box.

The order is rockerbox, spring, thrust 1/2", rocker, thrust 1/2", rockerbox alloy center, thrust 1/2", rocker, thrust 1/2", spring, rockerbox.

Ok, up it is going,
So the oil comes from the feed pipe, through the oil hole, into the hollow spindle, spindle fills, oil comes out of the oil holes at the top of the spindle, along the grooves at the top of the spindle lubricating between the rockers and spindles, out where the grooves are cut in the rockers with the flat washer against the rockers, oil is sent in the right direction and not restricted as it would be if the springs were against rockers then follows a downward path through the pushrod tubes to the followers/cam, down to the scavenge pump, back to the restrictor before the tank and starts again. Think I got it now, let me know if any of this is wrong. I know this all basic stuff to most here but if you don't know.
Let me know if there is anything else I should know
Thanks again

actually the oil pressure to the rockers is limited by the leaks at the various junctions

pressure is inversely proportional to drips per minute

Hi, Just this morning I tore down the rocker boxes on the '69 Bonnie. Motor has been apart before. Has non grooved shafts.

Crumudgeon, that is how they came from factory. The small hole washer went against wall of box & the narrow end of shaft went through it. Then spring, then rocker, then flat washer against center support. On left side of box there is the center support washer, rocker, spring, then flat washer against wall of box.

The prior mechanic on this motor installed a large hole flat washer between spring & rocker. Looking at this extra washer looks like it was sanded thinner. But looks like it was made from a large hole Triumph washer. So now there is 3 washers on the right rocker.

He also had swapped the spring & the outer flat washer, meaning washer is against rocker & spring against alloy of box wall.

Very closely examining alloy of box it is obvious spring has NOT been rotating whatsoever. There is on wear pattern & only a tiny shinny spot on alloy where end of spring was.

Trying to rotate spring with screw driver it doesn't want to move easy at all. The rocker very freely rotates on flat washer though so it doesn't try to rotate spring.
Don

Regarding grinding an oil slot in rocker, to be clear, John Healy did a straight slot, not spiral?
Thanks, Don

Yes straight line as its easy to do with a stone.

What John said is BSA used a groove in the rocker shaft on the triples (Triumph and BSA) and Triumph, in 1973, used a spiral (shaft # 71-3549). You can choose how you want to address this. What I did say if you choose a groove I feel you should keep it toward the top. All of the pressure is on the bottom of the shaft.
John

Hi Kommando,
I figured oil flow would be better if the groove was at the bottom because.
Oil flows in to the hollow in the rocker spindle.
Along the spindle and out of the oil holes at the bottom of the spindle in line with the groove.
Oil then runs along the groove.
Out through the cut between the flat washer and the rockers.
Then runs down to the push rod tops etc
Explain to me why this is not the best way.
Would the oil not need more pressure if the oil holes in the spindle were at the top, just to push it up there.
Really interested in opinions on this.

Hi John,
This might sound stupid but when you say all the pressure is on the bottom of the shaft do you mean the oil pressure or mechanical pressure on the shaft.
If for mechanical pressure do you think the groove would be better at the bottom for oil flow. Is this why triumph did a spiral as a good solution for mechanical and oil pressure.
If so is the spiral grooved shaft better than the straight.
I know I am still new at all this but that is why I ask so many questions that may seem simple to the more experienced on the forum.

A spiral spreads the 'weak' spot around the full diameter, the springs and pushrods both push the rockers upwards so the highest metal to metal pressure is at the bottom of the rocker and rocker shaft so last place you want a groove.

Hi Kommando,
I figured oil flow would be better if the groove was at the bottom because.
Oil flows in to the hollow in the rocker spindle.
Along the spindle and out of the oil holes at the bottom of the spindle in line with the groove.
Oil then runs along the groove.
Out through the cut between the flat washer and the rockers.
Then runs down to the push rod tops etc
Explain to me why this is not the best way.
Would the oil not need more pressure if the oil holes in the spindle were at the top, just to push it up there.
Really interested in opinions on this.

There is not a lot of oil pressure at this point, the feed comes from the return to the oil tank and only gets to the rockers due to there being a restriction/reduction in diameter in the pipe as it enters the tank to develop some back pressure. So if you get a blockage in the rocker feed all the oil goes back to the tank and the pressure never builds enough to clear the blockage as it just overcomes the restriction instead.

worry not. these lovely old machines were manufactured in an era where photography was rare, specifications were often changed without notice, and fascinating errors and mistakes were shipped out to the public, free of charge.

i've been messing with these things for 45 years and i discover stuff i never knew on this forum just about every time i look into it.

Ok, got it, spiral is best for strength and oil flow to lubricate between spindle/rockers but straight is as good to lubricate rockers / push rods / followers and cheaper if you cut it in to the existing spindle.
Thank you again.

Hi Commando and everyone who has posted,
After the rebuild and bike running I have really good oil feed to the top end where as before it was almost non existant ( I was going along the lines of thinking it was the inline oil filter I had fitted before the oil splitter causing less pressure to the rockers.. but the mod can be the only thing that fixed it.
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