There is a lot of confusion out there on valve train noise and its causes. Simple adjustments to the pushrod length will rarely solve the noise issue.

I’m going to express my opinions on this topic. This may provide clarity for some, but also, more confusion for others. Let me also state that most of my experience comes from the automotive field, and not necessarily Harleys in particular, but hydraulic lifter function is the same whether it’s a Chevy, a Ford, a Pontiac, or a Harley.

First you have to understand the basic theory of how a hydraulic lifters functions. A hydraulic lifter uses the engine’s oil pressure to fill the cavity within the lifter. As the lifter cavity is filled, the lifter plunger rises in its bore to the point that all lash or clearance is eliminated from the valve train. Since oil is non-compressible the hydraulic lifter is essentially solid at this point – except for the bleed rate engineered into the lifter design. In the simplest of terms this is how a hydraulic lifter functions.

Once the lifter plunger has been "pumped up" to eliminate the lash or clearance in the valve train, then any remaining noise in the valve train is coming from something other than lifter/valve/pushrod adjustment.

As for adjusting hydraulic lifters, in order for the lifter to perform properly and maintain zero lash in the valve train, the plunger must be set within its range of travel. This is where the term lifter “preload” comes into play. With the lifter on the cams’ base circle, adjustments are made to eliminate all lash from the valve train, and then further adjusted to compress, or preload, the plunger into the lifter body bore. On a Harley this is most often done by the use of adjustable push-rods, but the same result can be obtained using stock or other non-adjustable pushrods of the correct length.

Theoretically, as long as the lifter plunger is preloaded “somewhere” within its range of travel, and it does not bottom in its bore or extend fully to its retaining clip in operation, the lifter performance, including noise, should be equal. In Harley terms, whether you preload the lifter one, two, three or four turns of the pushrod, or .040, .080, .120, or .160, it should have no bearing on performance, including noise, provided the lifter is functioning properly.

Even though absolute value of the preload is not that critical in my opinion, setting the plunger near its midpoint of travel provides the most flexibility and service life and this is what I’d shoot for.

In my opinion, any noise remaining once the lifters/valves/pushrods are adjusted as described here is being caused by something other than adjustment, and some of the noise is absolutely “normal” for our Harley engines.

In the OPs case, attempting to quiet the valve train by changing to adjustable pushrods was simply grasping at straws. To repair anything, the first thing you have to do is make a accurate diagnosis, and diagnosing the cause of valve train noise on a Harley can be a never ending quest.

I don’t consider myself an expert on this topic although I think I have a pretty basic knowledge about it, and enjoy thinking about and analyzing stuff like this. If I’ve made any glaring errors or you have differing opinions, feel free to fire back. And hopefully this helps some of you while not confusing the **** out of this topic even more.

 

A little bit of noise is normal with a TC. I kinda feel out of place with everyone talking about cams and lifters. Since it only seems to happen in the rpm range you speak of, I'll throw one word out and hopefully nobody will rip my head off for saying it. Compensator.

 

If it had made this noise when it was new or just broken in it would be different. But since it has came about in the last 1,000 miles it's leads me to believe something is wrong and I'm not the kind of guy that will run it till it breaks. Its hard o diagnose cause it doesn't really do it loud when idling. It's loudest under load when your riding. Is there a chance it's oil brand related? I have always ran syn3 but the bike has it's. First round of rev tech synthetic in it. I also have a 07 dyna with the same oil that doesn't make the noise but theres only 4,500 miles on the bike 500 on the oil as opposed to 25,000 miles on my 06 2,000 miles on the oil.

 

Oil pump issue. Worn lifter bore. Bike doesn't like that brand of oil. Sounds like an oil pressure issue. I had a bad fuel cap that sounded like a valve lash issue.

 

rockers click when they wear..

 

Mine was ticking a little once in a while til a lifter finally gave out..I put in a set of Comp Cams V-Thunder lifters and it's been fine ever since.

 

2black1s dissertation on valve lifter and pushrod function is accurate and a good read but it assumes that the lifters are not bleeding down and the inherent noise is typical twin cam clatter. Maybe they are and maybe they aren't. Lifter service life is unpredictable; some will run 50K miles or more without issues; some won't. Not saying your lifters are the problem but it is a possibility.

However, you clearly state that the noise is new; occuring in the last 1000 miles and since you installed adjustable pushrods and changed oil, so let's start there.

It is possible, beause of factory manufacturing tolerances that you have less preload on on the lifters with the adjustable pushrods set at 2.5 turns than the preload set by the OEM pushrods. Adusting the preload as suggested in #3 is the first thing to do; taking them down to 3 or 3.25 turns might reduce or eliminate the noise. If the lifters are bleeding down a bit, more preload will also help.

You mentioned that this was the first oil change with RevTech synthetic. I know nothing about that oil but do know that the viscosity of different oils can make a difference in the amount of valve train noise. If additional preload on the lifters doesn't diminish or eliminate the bothersome noise, just for ***** and giggles, run a quality brand of conventional straight 50W oil, say Valvoline, Redline, Amsoil, etc. and see what, if any, effect that change in viscosity has. If the higher viscosity reduces the valve train noise you need to decide how important running synthetic oil is. If you want to run synthetics but want to try higher viscosity, Redline offers a 20W60 that might work for you. Personally, I run straight weight oils; I see no advantage to the premium price for synthetics but I change every 3000 miles. Don't worry about changing from synthetic to coventional and back again; it's not an issue. They can even be mixed with no issues.

I am sure nothing is wrong wtih your motor and you don't have to worry about "running it till it breaks"; it isn't going to break.

 

I installed the adjustable push rods thinking they would get rid of the noise. And since i have the same oil in my wifes bike 07 dyna and it doesn't have a problem with the oil i wouldn't think it was that. I plan on switching to mobil 1 v twin 20 50 next oil change since the pep boys sells it for $9 a quart on the shelf. I talked to a friend of mine that used to work for Jim's and he is almost positive it is the rocker arm bushings. I'm gonna open up the boxes and check for excessive play. If it's there i'll do the bushings and maybe the shafts as well if they are out of spec and ill re adjust the valves with the new parts so it has the correct preload.

 

I don't mind fixing something when it's broken or worn out. I just hate spending money and not fixing the problem. This is my first harley so everything is a learning experiance. I have always worked on my own cars and done everything on them myself including rebuilding the engine (minus machining). It's way to expensive to have anything fixed by a shop so I've been on here a lot and apreciate all the advice that i have gotten over the years from you guys. It's a good supplement to the shop manual.

 

Rocker arm bushings can certaily be the source of the noise but at 25K miles, very unlikely. Excessive end play is also often blamed as the source of valve train noise but shimming rocker arms rarely solves the problem.

The first thing you should do is put more preload on the liftere, at least 1/2 turn; see what happens.

Then change oil, don't even bother with 20W50, go to a straight 50W conventional (no need to change the filter) an see if viscosity has an effect on the noise.

If neither of those have any effect; replace the valve lifters; not expensive to do and since you have adjustable pushrods, not a lot of work. Lifters should last longer than 25K miles but many have gone south with less mileage. I doubt seriously that rocker arm bushings are the source of the noise but, anything is possible.

Valve train noise is the bane of many a Harley owner and drives some pretty near nuts trying to find and eliminate the noise. Manufacturing tolerances and how closely they are quality checked accounts for the reason why one bike is noiser than an identical bike.

Apparently your motor has not always been noisy, so something has changed. You havent' recently installed a windshield or change helmets or stopped wearing ear plugs have you?