free website stats program Connecting Rod Question | Harley Davidson Forums

Connecting Rod Question

danthern

Active Member
I have the top end on my 09 Road King disassembled because of a chirping noise that couldn't be easily identified. This is covered in a recent post and you guys were super helpful. The working diagnosis is piston slap (for whatever reason) and my new pistons are on the way and I have a machinist lined up to take the cylinders 10K over. I'm trying to decide if I should go ahead and change the tappets, push rods and rockers. It's a big bore 103 kit. The HD mechanic said no need to fool with any of that stuff because it's in good shape per his inspection. About 30K on the kit. Any feedback on that would be great but here's my main question. Should there be side to side movement in the connecting arms? There is no up and down play, which I was told to check for but the rod does move from side to side, the front more than the rear. Is this OK? Thanks in advance!
 
JMO but if you have it apart I'd replace it all. 30,000 miles is not that great but you do have 30,000 miles of wear and tear on it. Peace of mind knowing you have a fresh top end is worth the small cost.
 
I'm trying to decide if I should go ahead and change the tappets, push rods and rockers. It's a big bore 103 kit. The HD mechanic said no need to fool with any of that stuff because it's in good shape per his inspection. About 30K on the kit. Any feedback on that would be great but here's my main question. Should there be side to side movement in the connecting arms? There is no up and down play, which I was told to check for but the rod does move from side to side, the front more than the rear. Is this OK? Thanks in advance!

I agree with your wrench on the push rods and rockers but would replace the lifters with a set of CompCams VThunder 850-1 lifters; good hardware at reasonable cost.

It is normal to have side to side movement at the big end of the con rod; it will move from side to side on the crank pin as you describe and the front will normally move a bit more than the rear. The factory clearances are pretty tight but when Hoban Brothers reworks a crank, they set them up with much more. I would expect you will see about .025" -.030" side to side but wouldn't worry if you saw more. The main thing is no up and down movement; that is what will kill the crank.

Put it back together and run it.
 
I have the top end on my 09 Road King disassembled because of a chirping noise that couldn't be easily identified. This is covered in a recent post and you guys were super helpful. The working diagnosis is piston slap (for whatever reason) and my new pistons are on the way and I have a machinist lined up to take the cylinders 10K over. I'm trying to decide if I should go ahead and change the tappets, push rods and rockers. It's a big bore 103 kit. The HD mechanic said no need to fool with any of that stuff because it's in good shape per his inspection. About 30K on the kit. Any feedback on that would be great but here's my main question. Should there be side to side movement in the connecting arms? There is no up and down play, which I was told to check for but the rod does move from side to side, the front more than the rear. Is this OK? Thanks in advance!

Your machinist may have a better answer on the side play but I have always been told between .005 to.030. Here is a site that backs that up:http://forlubes.com/wp-content/uploads/Engine-Specifications2.pdf. As far as replacing the rest Jeff is correct 30,000 miles of wear on everything. If money is no issue peace of mind is worth a lot. If your money, like mine doesn't grow on the tree out back listen to your mechanic.
 
2007 specs are .005-.015 replace at wear of .020 side play between flywheels
 
2007 specs are .005-.015 replace at wear of .020 side play between flywheels

Thanks Jack, they tightened the specs up a bit. Then they go and loosen the specs on the flywheel run out, go figure eh?
 
NOW, This is ME.....

If you have movement from side to side on the rods, It IS normal...

You need the play to align the pistons and the cyl. bores...

IF no play from side to side, the Timkins bearings would be needed and a PERFECT alignment used so the rods would not press to one side or the other..

Answering your question.. up to 1/16 is normal and NEEDED motion...

There is NOT much push from side to side like forward and back... Tight up and down is the key here on checking.

My 09 King from 96" to the recent 103" build had the same as yours when apart.

I would go with the new 1023 gatermans for the lifters while apart..

They are the Cats Meow...

ALSO:
Check your run-out off the crank while apart so you know how that is... up to .003 and you are still good to go.

signed....BUBBIE
 
I'm getting ready to put new cams in my bike that has 27,000 on it. New V-Thunder (Comp. Cams) lifters are going in with the cams. You can spend a lot on lifters, but V-Thunder 850-1's are about $17 ea., and a good product.
New cam BEARINGS too! AT about $14 for two, it's cheap insurance.
 
Thank guys, great info and exactly what I needed to know. The pistons are due to arrive today so I'll hopefully be reassembling soon. I'll definitely drop in a new set of lifters since everyone here recommends it. Thanks again. I'll keep y'all posted!
 
Back
Top