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Harley Twin Cam Years To Avoid Like The Plague

Have you decided that it’s time for you to finally buy that Harley with a big Twin Cam that you’ve been dreaming about?

Great! You’ll love the feeling of the wind in your hair and the power of the Twin Cam.

However, you’ll be cursing your bike all the way to the mechanic if you buy a Twin Cam Harley from the wrong year. That’s right, some Twin Cam engines were plagued with issues and in this article, we’ll help you avoid them.

Here are the worst Harley Twin Cam Years to avoid.

Also Read: Harley Davidson Drive Belt Replacement Cost

Harley Twin Cam Years To Avoid

First off, don’t let this article discourage you from buying a Twin Cam Harley.

These issues happened a long time ago, and almost all Twin Cams on the road today are fixed by now.

There are many Twin Cams that are nearing the 100k mile mark and still running strong. This proves that if taken care of, these engines have the potential to last a very long time.

1999–2006 Models – Camshaft Chain Tensioner Failure

Let’s start from the beginning.

Twin Cam engines were first introduced into the market in 1999 and riders loved them.

However, as time went on, a large number of Twin Cam owners started experiencing problems with their engines, mainly – the cam chain tensioners.

The cam chain would eat away at the plastic cam chain follower shoes and then contaminate the oil with a large number of plastic shavings.

badly worn cam chain follower shoe

These plastic shavings would then get sucked in by the oil pump and clog the oil galleries and damage the oil pump. This means low oil pressure and catastrophic engine failure in severe cases.

To this day, nobody really knows the exact reason why that happened. Some mechanics speculate that the cam chain itself had sharp edges, while others speculate that the plastic followers were made of poor materials.

Whichever the case, Harley Davidson fixed this issue in 2006 for Dyna models and in 2007 for the rest, by replacing the spring tensioner with a hydraulic one.

There were no recalls, however, and no lawsuits, even though most mechanics agree that the cam chain tensioner parts were poorly made.

At this point, almost all bikes on the road have the hydraulic cam chain tensioner upgrade installed, but it would be a good idea to ask the seller whether they’ve got proof.

2003-2006 Models – High Crank Runout

If you’re thinking of buying a Twin Cam Harley from 2003-2006 then we certainly advise you to think again.

Apart from the same camshaft chain tensioner failure above, the 2003-2006 models also suffer from a high crank runout issue.

In 2003 Harley Davidson decided to save more on production costs and thus changed the legendary Timken bottom end to a pressed-in camshaft and roller bearings.

While this decision greatly reduced production costs and time, it create more problems for the Twin Cam.

The new bottom end had a weak spot between the crank pin and the flywheels. That weak spot allows the whole crank assembly to go out of truth and makes the crank too unbalanced.

This high runout causes the crank to wobble, which absolutely destroys the bottom end of the engine, including the block itself.

Now, keep in mind that this high runout issue did not happen to every single Twin Cam from that time period, though it did affect a significant chunk of engines. A lot of the engines affected by high runout had a Stage 2 and a Stage 3 (big bore kit) installed, so keep that in mind.

Make sure to ask the seller if he had any issues with high crank runout, or if the crank has been replaced. If the seller has no idea, we advise you to look for a different year bike in order to avoid this issue.

Conclusion

Here you go – the worst Harley Twin Cam years to avoid.

Now, while models made before 2007 had their fair share of problems, most of the bikes around today have had them fixed at some point.

To that end, I personally wouldn’t worry about them too much. But if you do find a Harley Twin Cam from one of the years on this list, make sure to ask the seller about any and all issues the bike might have had.

If the seller is not able to provide you with a clear answer, or if he’s hiding something from you, it might be a good idea to look for a different bike.

Harley Twin Cam engines are great, but as with anything else, they’re not perfect.

Thanks for reading and I hope this helped you out!

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