A flaw in the design of the Harley Twin Cam or TC makes it prone to multiple problems. Those problems have been too severe in several TC years, like causing engine failure. You should avoid those TC years.
Now, let’s know about Harley Twin Cam years to avoid. You should avoid the 1999-2006 TC years as they are problematic. The issues in the 2003-2006 TC years aren’t significant, but the 1999-2002 TC years bikes will need massive modifications.
We made a list of reported problems in those avoidable TC years, which we will discuss. This article will help you decide which TC years you should buy and which you shouldn’t. So, let’s go through the article.
Table: Several Harley Twin Years And Their Reported Problems
Here are some reported problems from different years of the Harley Twin Cam:
| Model Years | Reported Problems |
|---|---|
| 1999 | Rear cam bearing problem |
| Oil tube blockage | |
| Engine failure | |
| 2000-2002 | Cam chain tensioner |
| Lack of lubrication in the engine | |
| Silent failure of the engine | |
| 2003 | Wobbling while starting or idling |
| 2004 | Problems in the main circuit breaker |
| 2005 | Crank runout problem |
| Noisy engine | |
| 2006 | Wobbling due to Stator problem |
Harley Twin Cam Years To Avoid: Why You Should Avoid Them?
The Twin Cam 88 engine would have become an excellent vehicle model if the manufacturer didn’t make one wrong decision. Their wrong decision was they put the plastic foot and the metal cam chain together. This alignment of the plastic and metal makes the engine more prone to failure.
That’s why you better avoid or check twice before buying the 1999-2006 model years. Generally, it’s better not to buy any 1999-2002 engine without modifications. But, due to improvement in the design, you can think of buying any of the 2003-2006 TC years. But still, they are not free of trouble.
Twin Cam Years 1999-2002: Which You Must Avoid
Generally, in a 1999-2002 TC year, you might experience cam chain tensioner bearing problems. Also, oil tube blockage, lack of lubrication, and complete engine failure are common. The main issues of these years arise from its questionable design. Let’s see in detail:
- Cam Chain Tensioner
The tight tensioner can put excessive tension on the chain and rub against the plastic foot. As a result, the plastic will wear away soon. Then the metal cam will get access to the lever.
The abrasion between the level and the metal cam may cause metal pieces to break into the engine. This may result in a complete engine failure. As it is silent, you might have to check the condition of the tensioner frequently.
Watch this video to learn how to check the cam chain tensioner
- Blockage In Oil Pump
When the plastic wears down completely, it jams the oil tubes and pump. As a result, the oil won’t be able to flow toward the engine. Generally, this problem is more common in 1999 TC year.
- Bearing Problem
When the oil can’t flow from the oil pump due to the plastic jam, this bearing problem will arise. The bearings won’t get the oil they need for adequate lubrication.
Eventually, this lack of lubrication may damage essential engine parts like pistons and rods. This problem is more prominent in the 1999 and 2002 TC years.
- Engine Failure
This problem may arise due to two reasons. One is for lack of lubrication, and another is the inducement of metal scraps inside the engine. When the engine components don’t get enough oil and lubrication, the friction between the components will be excessive.
This hindrance in the engine lubrication system results in damaging the engine components. Also, metal scraps can enter the engine due to the abrasion of the metal cam and the lever. These scraps will hinder or imbalance the function of the type engine components.
Therefore, in the end, it will cause silent engine failure. The process of engine failure will be surprisingly quiet, unlike any other mechanical failure.
This issue is pretty generic for all 1999-2002 TC year models. But the 1999 and 2000 TC years have reportedly faced this issue more than any other.
Twin Cam Years 2003-2006: Reconsider Before Buying
In 2003-2006 TC years, keeping the design unchanged, the manufacturers of TC improved their cam bearing and breathers. Therefore, TC 2003-2006 years are better than earlier.
Because, though there won’t be any critical problems like those earlier years. You can solve those issues by using harder metal parts or applying a hydraulic cam chain system.
Several problems you will encounter in this 2003-2006 TC years are-
- Wobbling
The car will be sluggish or wobble whenever you try to start or stop the vehicle. This mainly occurs due to rapid acceleration or declaration of the bike. You will face this issue more in the 2003 and 2006 TC years.
When the crank run-out exceeds the tolerance level, it may cause burnout. Also, when the Harley code b1006 occurs, the regulator won’t be able to rectify the output voltage of the stator. This issue in the stator can be the reason for wobbling and problematic starting.
- Problems In Main Circuit Breaker
This will cause a temporary shutdown in the electrical circuit. Usually, on overload, the engine will produce greater heat. As a result, the connecting spring of the circuit will pop out, breaking the circuit connection.
Upon cooling, the spring will again pop back on the circuit, and the bike will function again.
- Crank Run-out And Noisy Engine
The tolerance level of the crank run-out is 0.01 for Harley TC. When it crosses this limit, there will be an imbalance and mistiming in the fuel ignition system.
This will result in a noisy engine, indicating the engine will fail soon. Mainly, it is one of the prime issues in the 2005 TC year model.
Modifications Necessary For 1999-2006 Harley Twin Cam Years
We always recommend avoiding the TC years 1999-2002. If you still end up buying one somehow, you can do some modifications to eliminate those problems. You can try these modifications on your Twin Cam 88 engine to make it less troublesome and useable:
- You can get different company’s aftermarket kits which contain gear drive camshaft kits. These are for replacing your chain cam system with a gear cam system
- Harley dealers also provide upgrade kits with high-efficiency oil pumps and hydraulic cam chain tensioners. You can use this for modifying your spring cam into a hydraulic one
- A hydraulic tensioner will control the tension on the cam efficiently while idling. Thus, abrasives operation will reduce
- The high-efficiency pump also will provide oil flow at high pressure at elevated temperatures. Hence, it will reduce the oil blockage risk
- Provide an appropriate grade of oil to avoid cam issues
- Install an oil cooler with a cooling fan. This will maintain the appropriate temperature in the entire oil system by blowing cool air through it
Best Harley Twin Cam Years For Buying
As you know the reasons for Harley Twin Cam years to avoid, you should choose the latest model. The manufacturers upgraded the design in the 2007-2016 model to eliminate the issues of the 1999-2006 models. The 2007-2016 model years are still the best for buying.
1. Upgrades In Harley TC Model Years 2007-2009
TC 96 of 2007-2009 had minor problems like smoke coming from the air filter, misfiring, and being unsuitable for the larger engine. Those are negligible, and you should focus on their improvement than their earlier year models.
- Offers hydraulic tensioner instead of cam chain tensioner. Thus, the chain becomes subjected to lower pressure at low RPM
- The cams are of bushing style, which replaces the bearing system. Hence, the bike is free from bear damage due to the low lubrication and wear out
- The vibration is less than those of earlier models due to the improved balance in the chain
2. Upgrades In 2009-2016 Harley TC Years
These model years offer a Harley Davidson Twin Cam103 engine model, with a better efficiency engine. These model years’ improvements:
- This Twin Cam model has a larger piston, bore, stroke, and compression ratio. These results in higher speed and performance than the earlier ones
- These TC years provide an oil cooling system for keeping the entire oil system cool. This prevents the engine from overheating, which is one of the most common Harley Davidson 103 engine problems
- Offers an eco-friendly design as they contain a catalytic converter that is capable of reducing pollution
FAQs
In this section, we will answer several questions about the problematic Harley TC years.
1. WHY IS SILENT ENGINE FAILURE OF 1999-2002 TC YEARS DANGEROUS?
If the engine failure process is noisy, you will get the idea that the engine is failing. So, you can take steps to prevent or resolve this issue before the ultimate engine failure, which isn’t possible in silent failure. That’s why it’s more dangerous than noisy engine failure.
2. IS THERE ANY RECALL FOR EARLIER HARLEY TWIN CAM YEARS?
Harley manufacturers did not recall their 1999-2002 versions but modified them slightly to reduce the wearing. They prioritize the cam bolt failure issue over the cam tensioner. That’s why they increased the warranty for the rear cam bearings.
3 WHAT ARE THE COST OF AFTERMARKET KITS FOR MODIFYING THE WORST TC YEARS?
Those aftermarket modification kits, like gear drive camshaft kits, will cost around $700-$800 without labor costs. Besides, you can purchase Harley modification kits at about $500 without labor costs. The labor cost may vary from one area to another.
Conclusion
If you plan to buy a Harley Twin Cam, you should know about the problematic TC years. Throughout the article, we discussed the Harley Twin Cam years to avoid with their reasons. Usually, we recommend you avoid buying 1999-2002 TC years.
If you still buy any of these TC years, you need to modify your bike to eliminate the risk of engine failure. The 2003-2006 TC years are less problematic but require some modification. That’s why you should buy the latest bikes of the 2007-2016 Harley Twin Cam years.