Chevrolet: aftermarket or custom rebuild?

Time changes everything.
Automobiles are in a time of great change.
Electric cars and autonomous automobiles are swiftly taking over as daily transport.
Petrol automobiles are becoming collectors items. Spare parts which are now cheap and easy to get are becoming rare and hard to come by.
We have stores of all kinds of rare and hard to find harmonic dampers and hubs and inertia rings.
We will be helping petrol powered auto owners to keep their precious collectible lovely cars on the road.
Naturally, our services to rebuild your old harmonic damper will cost more than a junky aftermarket part that won't last long and hasn't got a warranty.
We offer you a remanufactured OEM part for your old Chevrolet, Ford or Holden and it has a 5 year unlimited km warranty.
Our fee is NOT Competitive with Mexican parts, or Chinese parts.
Not Now.
But it sure as heck will keep your lovely old automobile on the road, purring like a happy cat.
And when the market for aftermarket cheap parts has meant those manufacturers have moved on to make other things and there are zero parts available from them, chances are, we will be here still refurbishing harmonic dampers, for what it costs us in time and materials to repair them.

Why can't you fix my damper, crank balancer?

Why can't you fix my broken damper, crank balancer?

There are some jobs we just cannot make a custom repair for, and there's a lot of reasons.

1. COST:- The design of the damper means that when it is worn out, it cannot be re-manufactured by hand without enormous cost to you, the customer. If cost is not an issue for you, we can put the time into our best effort at getting you a newly functioning damper. Because John is an aircraft fitter he can create all new parts if the damper is in such poor condition that it cannot be re-used. 
2. DESIGN:- Like a lot of mechanical parts, automobile and truck harmonic dampers were not created to be dis-assembled and re-manufactured. 
3. MANUFACTURE:- Manufacturing processes used to make them aren't conducive to repairing them. Parts like crank pulleys/dampers are made to a designated price; cheap and fast is the way they are made in the past 50 years. Recent dampers are made in temperature controlled robot factories using techniques humans cannot replicate.

Making parts disposable and only replaceable with new OEM parts protects manufacturers from law suits. It also guarantees that consumers must buy newer vehicles when old vehicles become obsolete.

Catch with this? Once all the old parts are sold your vehicle is off the road for lack of one small but crucial part - the crank pulley or harmonic damper.

That is where we can usually help you.

1930s Packard damper
What is it like inside?

So what are our specific difficulties?

Time.

Many of our customers need the part yesterday. This is because they checked the harmonic damper last in their maintenance schedule. We cannot make up for time our customers have lost by not sending the part to us in a timely fashion for repair.

Unforseen glitches in the repair process can take a lot of time to resolve. 

At HDR we take the time to give you a great result.

Dis-assembling the part to find out how it was made without breaking it.

Often the majority of time spent on a new job will be this seemingly simple task. If the delicate cast iron of the hub or inertia ring is broken it is really hard to repair so we don't break it. 

Complex dampers with flimsy light parts and large areas of rubber molded around internal metal components are almost impossible to dis-assemble without damaging the parts.

Parts are too worn out.

Some dampers are so worn out that there is no regular fix and the worn or broken parts must be repaired by hand. Cast iron welding, keyway cutting, new springs, inertia rings and hubs can all be made but at a cost of time and money for you the customer.

Unusual manufacture: 

We see crank pulleys from 100 years of automotive history. From Bugatti to Packard and Rolls Royce; GM and Ford to Hyundai, Renault, Datsun and Skoda. And everything else in between.

Because each crank pulley has been designed to dampen the vibrations from one particular style of crank shaft they are all unique. Functionally they do the same job, but the reality is that for every engine there is a different damper designed by a different group of engineers to solve specific harmonic vibration issues with the engine in the development stage. 

So unless we get a run of dampers to repair from the same year, make and model of engine, every job is very different and requires different skills. 

It's a dual hazard and joy of working in a custom rebuilding industry.

Successful difficult rebuild: Renault 05

We can't duplicate the way it was made to re-assemble it so that it works the way it was designed to work for your engine. 

Sometimes there is no alternative way to assemble it.

Over the past nine years we have developed a lot of different techniques using new rubbers, special bonding agents and the like to solve re-manufacturing issues but there is a limit to our ingenuity when it comes to re-assembling some crank pulleys.
Some components fail to:

1. Balance
2. Weigh the right weight 
3. Have the inertia ring run concentric with the hub
4. Include all the components they are supposed to contain in the space they were designed to occupy.
5. Run the pulley belts in the correct alignment
6. Have the timing in the correct place; 

Whatever the reasons for these issues, if they cannot be resolved it means we can't begin or complete the job. 

Toyota boat special before repair

Toyota boat special after repair

If we say we can't fix it we really mean it. 

It means that in our experience it will be uneconomic, or simply not possible to repair.

If you want us to go the extra mile, it's your call: feel welcome to have a discussion with us about your needs.

Making a completely new damper or a prototype damper for an engine which has never had a damper 

If you can afford the time and cost for us to put the time into hand crafting a completely new damper by making a new hub, inertia ring, rubbers, springs and other parts, most worn out crank pulley/dampers can be repaired so they work or alternatively completely accurately reproduced.
This could save your special engine from death in the back of the shed. 

Contact us damperdude - at - gmail.com and send some photographs of your crank pulley.
Or give us a call, we are friendly and keen to learn and share information. 00 64 7&863 3350

Check out our featured book http://quintessence.papertrell.com/id003678303/Lets-Fix-It

I'll get a second-hand pulley, she'll be right mate!

So your crank pulley is broke and you are shopping around for another one and the wrecker has a second hand one from the same make and model of car.
If your car is 10 years of age or older, there's a good chance that the pulley is as close to munted as the one you just took off the crank shaft.

Why?

Because RUBBER is why.
Rubber is the part that most often fails in a crank pulley, crank balancer or harmonic damper.
Rubber is an organic substance that breaks down with heat, water, oil, use and simple age.
All rubber parts of your automobile are going to die a slow sad death at some stage and require replacement.

When the rubber dies it usually does one of two things:
It cracks, shrinks, dries out and gets hard as a piece of wood.
It melts into a soft gooey jelly that is very messy to clean up.

So replacing your harmonic damper with a second-hand damper that may cost you just as much as a rebuilt damper means that it is inevitable that you will have to replace it again soon.

It also puts your precious automobile's engine at risk of catastrophic failure.
Check out our other blog posts to find out why.

We are totally happy to repair and re-rubber any second-hand or original OEM damper for you before you put it on your vehicle.

Care for your engine by buying it a re-manufactured damper/pulley or a new damper.

v12 Jaguar Etype before repair

v12 Jaguar Etype after repair before painting

Signs a crank pulley or harmonic damper is malfunctioning

It's hard to know what the problem is when your engine begins vibrating at odd speeds, or your passengers start being ill, or the windows wind themselves down.
These are all symptoms of the damper being out of whack.

Rubber weakens with age and also deteriorates due to excessive heat, oil exposure, solvent exposure, and contraction. So what happens when a harmonic damper is malfunctioning? What are the symptoms?
Here's a handy list for you to check out.

1.  Deterioration of the rubber between the hub and the outer ring. Shown as cracking, bulging or shrinking instead of forming a smooth layer level with the metal components. This will be likely in any crank pulley over 10 years old because of the natural deterioration of the rubber. So old OEM dampers may well not last well or perform their duty even if they have only sat on the shelf for the past 10+ years.

Don't forget rubber is a natural product that simply deteriorates over time.

2.  Any wobble of the balancer or wobble in the drive pulley.

3.  Excessive engine vibration.

4.  Crankshaft cracking or failure.

5.  Squeaking that does not stop when all other possible sources have been eliminated.

6. Excessive bearing wear.

7.  Excessive gearbox wear or failure.

8.  Failure of other rotating or reciprocating engine elements.

9.  Loose flywheel or pulley bolts.

10.  Slipping, slapping or noisy drive belts. Having to change belts frequently.

11.  Loss of horsepower and lessened fuel efficiency.

12.  Highly polished asymmetrical spons in the pulley grooves, means a warped inertia ring.

13.  Elongation of the balancer key-way or wear on the balancer hub or crankshaft.

14.  Failure in the alternator, power steering pump, A/C or water pump.

15.  Engines that don't run properly when adjusting the timing.

16.  Irregular idle.

When a damper wears, what happens, at a minimum, is that the outer ring will move so the timing mark will be in the wrong position. Or, at worse, the ring comes completely off while you're driving and becomes the worlds heaviest "Frisbee" under your hood. Your radiator is one of the favorite items your newly found toy likes to go through.

Causes of damper failure:- age, cracked hub keyways, incorrect damper for the engine or crankshaft, damage from improper mounting or removal. Bent or out of balance drive shafts, buckled or out of balance driving wheels, excessive heat and age.

If you have a high performance engine without fitting a correctly calculated high performance damper, a standard damper could completely self-destruct sending high speed shrapnel throughout the engine bay with destructive consequences that are not hard to imagine.

It is important to understand that while an engine from any manufacturer is designed by a team of qualified engineers, after market dampers are often designed by people who do not understand the very important principles of physics that are used to design harmonic dampers. Great care should be taken in the selection of any damper to be used as replacement for a stock or for use in high performance engines.

If a cast iron damper is replaced with a steel damper care should be taken that the mass of the steel damper is equal to the mass of the damper being replaced. Because steel is much lighter than cast iron this means the damper will be somewhat larger than the one being replaced.

I have seen after market-dampers that have failed in spectacular fashion after brief use and have customers who are returning to a stock damper due to unsatisfactory results with after-market replacements. As in any field of after market componentry there is a small sector that know what they are doing and a wide range of pirate imitators.

John Mallett

Limited Warranty TAC up to 5 yrs

Yes we do warranty our work repairing harmonic dampers.
The basics are :- 12 months unlimited kms warranty, return to our base.
Racing, drags, rallying, boy-racing, and other non-standard driving of the engine are expressly excluded.
For those dampers we make supercharger fittings for, or which are expressly for high performance we will cover on a case by case basis if there is defective workmanship and/or materials for our work.
If you only drive your vehicle occasionally we are happy to extend the warranty to 5 years.
If you are re-selling/passing on our work to another person/company we regret that we cannot extend our warranty to cover third parties (or more) without our express permission.
We particularly exclude original equipment manufacture (OEM) faults and materials from this warranty - since the remanufacture of the pulley relies upon re-use and repair of OEM parts.
Damage to the damper before it reaches our workshop is also expressly excluded from this warranty and repair of bent or broken parts will cost extra.
If the fault is not found to be our workmanship after we have repaired it at your request an additional full hourly charge for all time and materials will be made.

Customer Responsibilities are to:-

1. Remove the damper from the engine in an appropriate manner which does not damage it. 
2. Provide accurate timing marks - email photographs of the timing cover or mark TDC on the damper before sending it to us.
3. Providing your full contact details and honest details of the use for the damper eg boating, car, racing.
4. Handling and transporting the damper safely to us.
5. Re-fitting of the damper upon return in a way which does not damage it.

If you don't know how to do these things please ask us. damperdude (at) gmail.com or call 0064  7  863&3143

In all cases New Zealand consumer law and New Zealand laws apply to all transactions.

Harmonic Damper History - Who invented crank pulley balancers and why?

The inventor of the harmonic damper was Dr Frank Lanchester. He and two of his eight brothers started the Lanchester Engine Company in 1900. They had high standards for their engines and Dr Lanchester would tinker with each motor that went out the door to make it more perfect than the last one. He invented the Torsional Crankshaft Damper [harmonic damper] and the harmonic balancer to cut vibrations in the Lanchester 38 hp six which was introduced in 1907. In 1910 he invented the single and double counter-rotating balance shafts. The patents for which were purchased in the 1970s and used by Mitsubishi and licensed to other manufacturers to the present day. He also invented the steering wheel, amongst many other things.

Luke Brennan has corrected our account with more recent information: You may wish to refer to him as Frederick W. Lanchester. Fred, not his brothers Frank or George.

His damper patent was 12th September 1910. He licenced this to Daimler shortly thereafter. Not Frank – Fred.

Also you may also wish to read the superb “Royce and the Vibration Damper” by Tom C. Clarke, which casts strong doubt on the primacy (though not the brilliance) of Lanchester.

It would now appear that Henry Royce had developed a friction-based harmonic damper for his 30HP engines in 1906 but had failed to patent it.

Royce then developed an extremely effective spring-drive/viscous damper that was used on all RR vehicles until the 1950’s. 

Thanks Luke, as you can see, the inventors of things can be mis-reported or debated, they are long dead so who knows who really did what and when?

Harmonic dampers are called by a wide range of varied names. In truth they are all torsional vibration dampers. Terms like crank pulleys, balancers, power pulley etc are to varying degrees erroneous. The term harmonic balancer comes from some manufacturers using the hub as a convenient location for external mass balance weights. The reason for this is that it made fine tuning of engine vibration simply done by adding or removing weight from the mass balance.
Though it is common belief that large steel parts such as crankshafts are rigid and inflexible this is not true, when a force acts on a crankshaft it bends, flexes and twists just as a rubber band would. While this elastic deformation is often very small it can have a significant impact on how an engine functions.
All objects have a natural frequency that they resonate or vibrate at when struck. An everyday example of this is a tuning fork. The sound that a particular fork makes is directly related to the frequency that it is vibrating at. This is it's natural frequency which is dictated by the size, shape and material of the fork. A crankshaft is a series of tuning forks in a line, it has a natural frequency that it vibrates at. When an object like a crankshaft is exposed to a heavily amplified order of it's own natural frequency it will begin to resonate with increasing vigor until it vibrates itself to pieces. This is called fatigue failure.
Crankshafts twist back and forth a small amount every time a cylinder has a power stroke. This motion is complicated because the amplitude of the vibration varies along the shaft. The crankshaft will experience torsional vibrations of the greatest amplitude at the point furtherest from the flywheel or load.
Engines have major and minor critical rpms and are different due to the fact that some harmonics assist one another producing large vibrations whereas other harmonics cancel each other out. Major critical rpms have harmonics that build on one another to amplify the torsional motion of the crankshaft. Conversely, minor criticals are at rpm that tend to cancel and damp the oscillations of the crankshaft. If the rpm remains at one of the Major criticals for any length of time fatigue failure of the crankshaft will result. These major critical rpms are dangerous and must be avoided or properly damped.
The oscillation of an undamped crankshaft at a major critical speed will commonly shear the front crank pulley and/or the flywheel from the crankshaft. I have seen hub keys sheared, flywheels loose, and pressure plates coming apart. These failures have often required crankshaft and or gearbox replacement and in extreme cases the diff.
Technically, 'the primary purpose of a harmonic damper is to cancel out third harmonic distortion by using intermodulation between the second harmonic and the fundamental in the space charge regions of the triodes.'
Put simply the harmonic damper works by relaying resonance and torsion energy out of the crankshaft and dissipating it as heat by flexing a heavy metal inertia ring which is mounted on a vulcanized rubber cushion. Essentially the damper is a simple spring of rubber plus a vibration and heat absorbing mass - the hub and inertia ring.
Harmonic dampers are made of cast iron for the primary reason that cast iron has the ability to absorb and dissipate large amounts of energy because of it's high specific gravity. The damper on each engine is designed for the specific range of vibrations that a particular engine produces. Keeping the damper cool is also of primary importance.
The key weakness of the harmonic damper is the rubber. Next blog we will cover signs your harmonic damper or crank balancer is dying or dead - it's serious engine damage ahead if you keep driving it vibrating like that folks.

Ford Thunderbird repaired ready for painting.

Harmonic Dampers - Who Cares? We do.

What is a Harmonic Damper? 

Why should I be bothered about it when I am rebuilding my engine?

In the eight years we have been repairing these automotive parts this is our most often heard query, even from experienced mechanics and engine rebuilders.

• Harmonic Damper or Torsional Vibration Damper is the correct name for the crankshaft balancer or pulley which is on the front of the crankshaft of your car, bus, truck or boat engine. It absorbs critical vibrations in your engine which would otherwise cause the crankshaft to fail and the vibrations would rapidly wear out other engine and vehicle components.
• There are hundreds of harmonic damper designs but the most common design uses a metal hub with a spigot on which the oil seal runs. On the outside of the hub is a layer of rubber and on the outside of that is an inertia ring of metal. 
• The damper works because usually they are made from cast iron, which of itself absorbs vibrations, the rubber also absorbs vibrations acting as a spring and the inertia ring dissipates harmonic vibrations in kinetic energy and heat. 
• The design of each damper has been engineered to match the vibrations set up by your engine. This means that just any old damper or balancer won't work on your engine, you must use the one that was manufactured for your engine.
• Rubber tends to last only about 10 years, after then it breaks down becoming either shrunken and hard, or soft and gluey. At this point the harmonic damper ceases to do it's work and wear will occur in your engine.
• Most engine rebuilders only consider the harmonic damper as the very last item they have rebuilt on an engine; some rebuild the engine and ignore the damper altogether. This is a mistake as if the engine needs rebuilding then likely the damper will need it too.
• Rebuilding an engine several times because of damage caused by a malfunctioning harmonic damper can be very expensive.

Our small team are working every day custom remanufacturing to as-new or better standards Harmonic Dampers for dozens of different makes and models. 

Contact us 

• If your engine is vibrating at different speeds
• If you are rebuilding your engine
• If you are a collector of classic cars and engines

damperdude - at - gmail.com

Our service isn't fast or cheap but it will provide you with many more years of comfortable safe driving in your precious collectible car, truck or boat.

Yes we are based in New Zealand and yes we do trade internationally. We accept credit cards, paypal and payments direct to our bank account.

International Fire Truck before restoration - note rubber distortion

Buick 1950s before restoration

Buick after restoration with custom made rubbers

Cadillac after rebuild with new hand laid rubbers inside

Copyright Harmonic Damper Rebuilds Ltd 2019

29 Russell Street Waihi

3610 New Zealand