I'm sorry if this is going to be a super long description. The cliffs notes are that I have found excessive play (0.05") on the male connecting rod (front cylinder) at the crank pin. I am going to be rebuilding this motor myself and I need help choosing what parts to use. I will explain my goals in detail at the end. I get to the point and specify my questions starting at the
orange text below in the second post.
A little background information ...
I have a 2016 CVO Street Glide with 49,000 miles. It's pretty much stock with the exception of a Covington Customs Destroyer exhaust and V&H FP3 tuner. I run the bike hard at 90-100 MPH regularly and often times in high temps. 3-4 trips from Detroit to Dallas and back per season (I typically do this straight through, about 1200 miles). I usually have a couple decent trips out to the East Coast and back etc. I get around 20k per year on this bike. I'm a big guy (about 350 lbs) so I'm probably pushing the weight limitations with loaded saddle bags and a large bag on the luggage rack. Add another 170lbs if I got the ol lady with me. That equates to roughly a half dozen or more 17 hour 1200 mile days in 90 degree plus temps while hauling around 500lbs. I dial it back a bit when I have the wife, we try to do around 600 miles per day or less. But that's approaching 700lbs on the bike. So basically I torture it all summer long
That said, I do try to stay on top of my basic maintenance. I run down the entire PM checklist in the service manual every 5k with fresh Redline in all 3 holes.
Early in the season (around May) I noticed a LOUD chirp. If you've ever been in a machine shop, think about the sound you hear on a mill when trying to take away too much stock in one pass with an end mill cutter (metal on metal). My exhaust is EXTREMELY loud and I can hear clearly hear the noise at high speeds, radio turned all the way up, full face helmet on. Other bikes next to me hear it. It seemed to be most noticeable between 3000-3500 RPM. We were in Nashville when I first noticed the chirp. I pressed on to Dallas, all the way back to Detroit. Right back to Nashville the following weekend. Did another 5k trip in July with the wife. Aside from being super annoying I never noticed any other symptoms. No loss of power, no excess metal shavings on drain plugs etc.
I chased this damn noise around all summer long. I googled my ass off, I had several mechanics ride it and try to diagnose it. I wound up replacing a lot of parts.
I tried lubing the belt based on google search results, despite the fact that Harley seems to advise against it
SE Compensator (the stock one was pretty much shot anyway)
Transmission shaft inner primary bearing race and seal (I was right there doing the compensator so why not.)
Primary chain and tensioner looked fine
Inspected clutch release bearing and rod
Disassembled and inspected clutch basket and assy.
New lifters
Installed Rocker Lockers
New Breathers
Inspected and lubed all motor mounts
Checked for exhaust leaks (did not find any)
Removed and replaced exhaust gaskets anyway
New hose clamps for heat shields
Cut back exhaust heat shield where it had been rubbing on the rear brake pedal
Pulled the cam chest cover and found nothing out of place
Inspect rear wheel compensator (I probably should have just changed it)
Took apart the fairing looking for loose cables/wires rubbing
Disassembled the air cleaner and inspected the throttle body and butterfly valve thinking maybe it had become worn
None of this stuff made a bit of difference. I learned a LOT about working on my motorcycle in the process but I can't even put into words how defeating it was to pull the bike down off the lift and hear that noise after each attempt to resolve it.
Over 10,000 miles later around mid September, the noise had gotten noticeably worse. I had a 3000 mile run to Texas and Oklahoma coming up quick in the first week of October. I asked one of my club brothers to test ride it for me. He's a pretty knowledgeable guy, 50+ years in the club. Hasn't worked on a lot of Twin Cams but he's been riding Harleys and fixing them since my parents were kids. After the ride he looked at me and said. DO NOT RIDE THIS MOTORCYCLE TO TEXAS!
So I started tearing the motor apart. I didn't find anything out of line for a bike that has nearly 50k as I worked my way through the top end. When I got the jugs off I found the connecting rod for the front piston had a lot of vertical movement at the crank pin. I measured 0.05" with my dial indicator. I believe this is called a "rod knock"? If you managed to read my entire story above, I never heard a knock type of sound. It was a chirp I had been chasing. This is why I went through the trouble to explain the entire situation above. Maybe someone can shed some light on what I'm missing here. I'm pretty stumped on the noise. Maybe I was getting some piston slap and that's what I was hearing over the knock?
Either way, the wear between the rod and crank pin needs to be dealt with.