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I am looking at the inner cam cover (26) where the shafts for the rockers (27) go through.
Are these supposed to be just plain alloy without any bushes? The shafts seem a little loose in them (at least when not bolted up). The engine has about 40,000 on it.
The chrome on them and a few other covers was flaking and so I had them de-chromed with a mind to polishing them up. I'm just wondering if there were bushes and the de-chroming ate it?
Parts book and manual suggests not, but does not give any suggested tolerance either. They're not Shovelhead loose but it's less than a sliding fit.
I don't know if the factory sizes them individually (do they?) but I was careful numbering them as they came out.
I discovered the expensive way that de-chroming does eat zinc/brass alloy bushings ... .
27 doesn't move, 21 does, 21 is where your bushes are. 26 clamps 27 tight and locked in one place indicated by the keyway on it where the bolt passes through. 21 pivots.
25 is your inner rocker cover not a cam cover and bolts 2 and 3 sucure the inner rocker cover to the top of the cylinder head and also secure the rocker arm shaft to the inner cover. No there at no bushings and the shafts can wear causing excessive play and noise. I replaced mine at about the same mileage you are currently at.
25 is your inner rocker cover not a cam cover and bolts 2 and 3 sucure the inner rocker cover to the top of the cylinder head and also secure the rocker arm shaft to the inner cover. No there at no bushings and the shafts can wear causing excessive play and noise. I replaced mine at about the same mileage you are currently at.
Interesting.
Does 27 move relative to 26? I'd think that the bolts holding 26 to the head and keeping 27 from drifting out would also serve to lock them in place, and that therefore the motion of 21 would all be relative to 27, which does not move.
26 is the cover and all of it is fixed and nothing moves
27 is the rocker arm shaft held in place by # 2 a bolt see slot on 27 as its timed in place to the front in the front exhaust and to the rear on the front intake rocker arms #27 / #22
23 is the bushing and two are in each of # 22 and it #22 rocks up and down on the #27 shaft as 4 # 27 is in each motor -- hope that helps
26 is the cover and all of it is fixed and nothing moves
27 is the rocker arm shaft held in place by # 2 a bolt see slot on 27 as its timed in place to the front in the front exhaust and to the rear on the front intake rocker arms #27 / #22
23 is the bushing and two are in each of # 22 and it #22 rocks up and down on the #27 shaft as 4 # 27 is in each motor -- hope that helps
Thanks. That makes sense.
I understood the OP to be saying that the motion of his 27s had hogged out his 26s leaving a loose fit. Hopefully I just read it wrong.
This gent found the play in those rocker shafts caused a tick that he fixed as follows. This is a TC but the concept is the same.
Originally Posted by Harleycruiser
First I want to say I’m sorry for taking so long to give an update, I have been busy and it is riding season ;-)
I got the motor back together and it runs great. I went with Andrews 21 n cams, and also change from the hybrid set up to the 07+ roller chain set up. It is a much better set up in my opinion and getting rid of the inner quiet chain that has caused so much trouble for me.
With the new set up the bike was fairly quiet until it warmed up then had this annoying tick that it has had forever. I’ve had four different sets of lifters, three different cams, three different cam plates, adjustable push rods set at all depths, two different sets of rocker arm assemblies, I’m sure the list goes on but you get the idea, everything has been changed at least once, still had the annoying tick.
Then I saw this.
I went out to my shop to look at my old set of rockers arms and sure enough there is about a 32 of an inch slop between the hole and the bolt that fastens the rocker plate down and locks the rocker shaft from turning. This gap allows the shaft to rotate and hit the bolt causing the annoying tick that everyone is chasing.
So any problem has to have a solution, a bushing to go between the bolt and the shaft. I found some brass tubing that I had, reamed it out for the right clearance, made a tool to taper it to lock it into position. Installed them and no more annoying ticking, yes I still have a real minor tick that I know is from rocker endplay but I am going to address that later.
For the first time since the bike was new I am riding without ear plugs, what a difference.
You can tap them in, use a clamp to pull them in, or pull them in with the bolt once you get them started. You don’t even have to remove the rocker arm assembly from the bike, just loosen it.
I am working with Bikerscum, (who made the video) on this project. I have made up several extra sets and we are anxious to see how they work for other people.
We are giving them out, all I ask is for five bucks shipping cost.
There have been several other fixes for this problem including drilling/taping for a set screw on the support plate/shaft, drilling for a pin, or even Locktighting the shaft. But in my opinion the bushing is the most practical.
It is tapered so that it locks into place and wedges between the shaft and bolt. Another benefit is that the bushings center the rocker arm plate and guarantee that it the rocker arms are always positioned on the valves at the same wear pattern every time.
It also centers the pushrods better to help prevent rubbing the tubes.
So if anyone is interested, if you have been chasing that tick in the top end, and you will use them, let me know and I will get a set in the mail. Autonews2@yahoo.com
I understood the OP to be saying that the motion of his 27s had hogged out his 26s leaving a loose fit. Hopefully I just read it wrong.
You read it right ... Although, I don't know if they have hogged out the housing, or how they are meant to fit in the first place (i.e. factory tolerances).
Sorry for the brainfart over "cam cover".
I had cam cover on my mind, as when I had the parts de-chromed, I de-chromed it as well and, contrary to what I was told, it ate out the cam and pinion shaft bushes.
Someone did not read the label ... "Muriatic acid is a fast, cost effective zinc removal agent". Any alloy containing zinc will be reduced.
Nice fix above, BTW. I respect that kind of attention to detail.
I'm thinking that the Rocker Arm Shafts, p/n 17611-83, should be a sliding fit. They don't move so they should not need bushed BUT they should fit well. THey are about $9 new, but if new does not fit well, what to do?
I see some suppliers like Sifton actually sell a .005 oversize shaft, so this may well be an issue.
So, the rocker arm shaft is .550" diameter. Actually, I'd say a few thou over.
Good catch guys, these ones are definitely worn on opposing sides where you would expect it and slightly where they fit into the cover. Not a lot but enough to feel with a finger nail.
It seems like the worst only moves up and down about 2 or 3 thou which is still in spec but the manual mentions chucking the cover and replacing it if they go out of spec.
I suppose it could be bushed if you had access to the equipment. Does anyone do that?
THe H-D Rocker Arm Bushing Reamer has .555” diameter.
Where can you get shims to shim the end play and what is the thinnest it is safest to go to?
One of them is up around 10 thou.
Thank you.
Last edited by Lucky Luke; Aug 14, 2015 at 05:08 PM.
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Bushes on inner rocker covers
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