free website stats program Crank Runout, How to check? | Page 2 | Harley Davidson Forums

Crank Runout, How to check?

The crank run out can show up in the 96 unmodded engines too. It depends on how you ride. Sudden missed downshifts to the wrong gear or doing burnouts will shift the flywheels.
 
The crank run out can show up in the 96 unmodded engines too. It depends on how you ride. Sudden missed downshifts to the wrong gear or doing burnouts will shift the flywheels.
What about Wheelies?:D I only did one, and it was a accident:52::p
 
TQ,

Thanks for the info. My problem is this. How much runout is too much and will cause damage to the oil pump? I would think if .005" will cause damage to the gear drive setup, it is still going to cause damage to the oil pump.

My bike has 35000 miles on it and it runs great and is smooth, but I am just wondering if I should go ahead and get a crank, already welded trued and balanced and just plan on doing the entire engine. I did speak to Andrews and they said .002" was the limit for the gear drive. But do I really want more than that causing other damage.

Just trying to think this through all of the way.

Has anyone checked and found no runout or are all Twin Cams doomed?

Eric

The number 0.012" sticks in my mind. I think HD changed the MAX spec to that BECAUSE the old spec was being exceeded too much.

The runout problem is more of a phenomena on the larger displacement bikes with the OEM (HD) cranks. Also bikes that are abused (heavy shock loading from burnouts, frequently popping the clutch or radical downshifting). The whole problem is the two sides of the crank twisting on the connecting rod pin which is only a press fit on this design.

Apparently, the newer SE crankshaft is stouter than the HD version. But I think if you are not having problems, it is WAY overkill to tear apart the engine "just to do it". That could introduce all sorts of other problems you may not now have.

If you check your runout and it is OK, I would do the mods you are thinking about, especially if that is the roller chain conversion. Much more forgiving. But there is a guy on here that had his crank twist and nuke the pump. Pieces. Luckily in his case, the Motor Company came through. You can read about that here:

Consideration when looking at bikes with 96ci or greater - Harley Davidson Community

TQ
 
Well, I think I will pull it apart next week and check it. I have to get Hernia surgery Monday and that will give me something to do afterwards. I may take it apart Sunday and see what it is, then I can make a plan while recovering. I'll post up my findings also.

Smitty, I agree after 35000 miles, it can't be that bad. I am just looking at several options. I honestly can't see finding out you had .004-.005" of runout and just saying Oh well, I'll just put the chain conversion on. I am the kind of guy who wants everything to be right if I am going to do anything.

I'll let everyone know what I find. Maybe it will be fine.

Ride Safe!
 
But I think if you are not having problems, it is WAY overkill to tear apart the engine "just to do it". That could introduce all sorts of other problems you may not now have.
TQ

I'm not considering ANY engine mods. Haven't even done pipes, TFI, or air cleaner upgrades. I simply don't want this issue creeping up on an unwarranted bike and taking out the oil pump and then the motor. If you were in my shoes, would you go through with the procedure to check the runout or just keep riding? Would you skip the inspection and just invest in an extended warranty?

Thanks - you know about a million times more than I do about motors so I truly value your opinion - and, of course, anyone else's who cares to contribute here.
 
I'm not considering ANY engine mods. Haven't even done pipes, TFI, or air cleaner upgrades. I simply don't want this issue creeping up on an unwarranted bike and taking out the oil pump and then the motor. If you were in my shoes, would you go through with the procedure to check the runout or just keep riding? Would you skip the inspection and just invest in an extended warranty?

Thanks - you know about a million times more than I do about motors so I truly value your opinion - and, of course, anyone else's who cares to contribute here.

If you do not have any HP producing mods, and are not screamin' up and down the road tryin' to ruin the engine, you will probably NOT have this problem. The folks that do seem to have something they can point to as the contributing factor. With an '08, you already have the roller chain, so there is no real reason to get into the cam chest without symptoms of a problem. Not sure if that bike has the INA inner roller bearings or not. If it does (Glider probably knows), then that might be justification for getting in there to swap them out. Much more likely of problems like that then with the runout unless the engine is pushed hard.

But if you do have the INAs and choose to swap them out, that would be the time to measure the runout just to know. Would make you feel better anyway. Breaking into the case to weld and true the flywheel "just to be safe" would not be justified IMHO. HD would not cover any of that unless something had happened to justify a warranty claim. And, in fact, they would NOT sanction that anyway.

With respect to insurance, that is a matter of personal choice. It was already on my bike when I bought it, so I did have it transferred to me. Good through '10, but I have probably done enough to the bike that it would not apply anyway. So it depends on what you may do to the bike, and what you want to protect against. If you are leaving the bike fairly stock, and want protection against the big stuff happening, it might be worth it, but should not be all that expensive. The odds are in favor of the insurance company, so don't give them too much money.

TQ
 
Last edited:
Awesome. Thanks TQ.

Oh, one more thing - what's an INA inner roller bearing, what does it do, and what would you swap it out for? Sorry, three more things!
 
Awesome. Thanks TQ.

Oh, one more thing - what's an INA inner roller bearing, what does it do, and what would you swap it out for? Sorry, three more things!

The INA are a cheap roller bearing that HD uses on the inner end of the cam shafts (pressed into the case). These have had problems, and when that happens it is usually a REAL problem. Bits of hardened steel throughout the engine.

The replacement for the INAs is the Torrington roller bearing. The post below talks about the swap and has some good pix of the difference in the bearings:

Cam Bearings - Harley Davidson Community

TQ
 
Thanks again TQ - I learned a ton tonight and you really earned your pay this evening!

You do get paid, don't you? :s
 
Back
Top