Rocker bearings

Top End (cylinders pushrods etc.)
Post Reply
jank1331
Member
Posts: 42
Joined: Sun Sep 12, 2010 2:53 am
Bikes: 1958 FLH
Location: California

Rocker bearings

#1

Post by jank1331 »

Greetings,
The Rocker arms on the front intake and exhaust have a pretty good amount of side play in their bearings. I've read all of the posts on this topic and it doesn't seem to be a "fatal" issue. The top end was recently rebuilt and currently has 1200 miles(Which seems low to start having these issues). The rear rocker bearings are solid with no side play but the fronts like I said have a good amount. I haven't found any specs for allowable side play in my shop manual. Should these bearings be replaced or can I run them? What is the cause of this with so few miles?

Also, does anyone have a recommendation for a solid, honest, reliable shop that does good work in the Sacramento CA area?

Thanks,
Steve
Cotten
Senior Member
Posts: 6937
Joined: Sun Feb 10, 2002 2:30 am
Bikes: -
Location: Central Illinois
Has thanked: 112 times
Been thanked: 310 times

Re: Rocker bearings

#2

Post by Cotten »

Jank!

Your question is not entirely clear;
Front and Rear?

You mean the rear head is sweet, but the front is loose, or?

Pan rocker "bearings" are a bronze cap block upon a cast iron (or steel I forget) bed block.
Ordinarily end-play is ignored, and side-play usually only occurs after decades of service: One of the reasons Panheads lasted long enough to be legendary.

So my question is: Were your rocker blocks really re-built with the rest of the motor?
They are ritually over-looked, primarily because modern replacements for the arms themselves are questionable.
The rebuild involves grinding both blocks shorter, and then reaming and honing to fit each arm while torqued to spec.

Does the motor run poorly?
Excessive noise can come from other concerns.

....Cotten
katto
Member
Posts: 62
Joined: Fri Aug 28, 2009 6:05 am
Bikes: 1948 panhead
Location: usa
Has thanked: 3 times
Been thanked: 2 times

Re: Rocker bearings

#3

Post by katto »

My Panhead Service Manual says; Rocker Arms fit in bushing..... .001-.002 in. loose. End clearance..... .004-.012 in. Hope this helps.
jank1331
Member
Posts: 42
Joined: Sun Sep 12, 2010 2:53 am
Bikes: 1958 FLH
Location: California

Re: Rocker bearings

#4

Post by jank1331 »

Katto,
Thanks, that does help.

Cotten,
What I mean is that when both valves on the front head are closed, the rockers (Intake and exhaust) can be moved horizontally back and forth, like the bearing cap and block is smaller in length than the rocker. My question is do these need to be replace? Or since it is a common issue, can I continue to run them without damaging anything?

Steve
Cotten
Senior Member
Posts: 6937
Joined: Sun Feb 10, 2002 2:30 am
Bikes: -
Location: Central Illinois
Has thanked: 112 times
Been thanked: 310 times

Re: Rocker bearings

#5

Post by Cotten »

Steve!

Endplay is not easily 'adjusted'.
Usually silver solder is sweated on to one end of both blocks, and then lathe-cut upon a mandrel to spec, (preferably prior to re-fitting the bore).

Some early 80's Shovels came from the Factory with nearly .030" endplay, so I do not worry about Pans until they rattle when you lean into a corner.

....Cotten
jank1331
Member
Posts: 42
Joined: Sun Sep 12, 2010 2:53 am
Bikes: 1958 FLH
Location: California

Re: Rocker bearings

#6

Post by jank1331 »

Cotten,
Thanks for the reply. On a side note, do you know of any shops in the Sacramento CA area that do good work?
Billpan58
Inactive member
Member
Posts: 112
Joined: Mon Jul 19, 2010 2:36 pm
Bikes: 58FL
99M2Buell
89Sporty
Location: Sanford,mi.
Been thanked: 1 time

Re: Rocker bearings

#7

Post by Billpan58 »

highway choppers,glendale,az. great shop
Post Reply

Return to “Top End / Cylinders / Pushrods / Lifters”