View Full Version : Pins on balancer (ASP underdrives)

04-09-2003, 08:23 PM
Ok, ok....before you go telling me to look at all the past threads on this subject, please hear me out. After reading arguments on whether or not to remove the pins from the damper when installing ASP underdrive pulleys, I really don't know which is the correct way. So, once and for all....do the pins need to come out or do they stay? Thanks!

04-09-2003, 09:03 PM
leave the pins in, they are for the crank balance, not the pulley

04-10-2003, 10:38 AM
The pins are for pulley balance.

Yup, now you are back to square one - two opposing opinions.

Look at the size and location of the pins - they are really too small to balance the crank. They are there to balance out the stamped steel pulley.


04-10-2003, 11:10 AM
Balance Pins
Ford Shop Manual 1989 Section 21-15-11
Ford Shop Manual 1995 Section 03-01A-32

Engine Front Cover (assembly/disassembly instructions)

Step 15.

If the crankshaft damper is being replaced, check if the original damper has balance pins installed. If so, new balance pins (E0SZ-6A328-A or equivalent) must be installed on the new damper in the same position as the original damper. The crankshaft pulley (new or original) must also be installed in the same relative position as originally installed.

The damper and pulley are balanced as a unit probably by the welded weight on the pulley and by removing material from the stock damper. The balance pins in the damper would then be to final balance with the rest of the engine and not the damper/pulley assembly.

I would say that if you are installing a new crank pulley, it would be best to have the new pulley/old damper balanced as a unit without the pin, then reinstall the pin before putting it back on the motor.

If you are installing a new pulley and a new BHJ balancer, you should have the pin reinstalled in the same location for engine balance.

Of course, as blackbirdsc (Steve Webb) has told me, an 80,000-100,000 mile motor will be internally out of balance due to wear and carbon deposits that that pin weighs! Big thanks also to Duffy for finding the information in the shop manuals. Duffy also got that the pins were for final engine balancing from a retired Ford engineer.

04-10-2003, 11:28 AM
i had a pulley spun up (along with other parts), its neutral, it already has balance "pucks" in it. Unless the place that builds 2000 plus hp small blocks and has also done a few 3.8s SC engines and tested out some coy miller parts on his in house dyno decided to "crack" out:D

If you have a BHJ you probably will have to install "mallory" metal in place of the balance pins

04-10-2003, 01:13 PM
If you had a stock setup spun up and it's balanced, then the pins are for fine tuning the crank balance. I didn't know of anyone who had the setup check before.
I can't see how much those pins are really doing - mine had one pin. When placed only a couple of inches from the axis, you don't get a whole lot of effect.

I read that part in the shop manual but felt it was in error. I just didn't think Ford would spend the time/money to balance to that level when they made such a cheap balancer to begin with.

With 110k on my engine and one one pin in the old balancer I don't think I'll have my BHJ drilled for mallory metal.


04-10-2003, 07:23 PM
i wouldnt bother either, I doubt anyone actually noticed a vibration(even minor) with/without a pin...but if the engine is apart FOR SURE get it all rebalanced

04-11-2003, 02:12 AM
I've broken two dampeners relocating the pins to like stock feeling a vibration each time. Using the pulley that came with the replacement dampener. If you want to go ahead.

I've had three assemblys taken right out of the box and checked everyway. (mainly because this keeps coming up) I wish Duffy and George would do this also.

Assembly out of box=neual
Pins removed = screwed
Dampener without pins or pulley = nuetral
ASP pulley and dampener with pins removed = nuetral

R Code 3.8 internally balanced

R Code flywheels (manual and auto) = neutral

I don't car even if Ford used the entire rotating assembly when selecting pins at the factory because now they ship new assemblys out balanced as is, if they wanted us to reuse the factory pins in the same location they would have had instructions to do so and there wouldn't be any pins in a new one. Ford doesn't sell dampeners alone because this method won't work, the pulleys are not balanced, they are close, but not. I know because I've checked and used and checked.

The only way the reuseing pins method is valid is if you are reusing the existing pulley that came with the motor on another dampener. Not with a new pulley of any brand or balance.

Anyone who builds engines right can tell you than an internally balanced engine that specifies zero imbalance flywheels and dampeners needs to have zero imbalanced flywheels and dampeners. If you install a zero imbalanced dampener (which ours are without pins bar none no matter what) with a zero imbalance pulley (which all ASP pulleys are bar none no matter what) and then go sticking pins into it no matter how many or where it will no longer be balanced. If you think this is the way your engine is supposed to be then you will feel the same things and have the same success I did when I first found that BS info in the shop manual back in 1995 and did it two times in a row. I just doesn't work, no matter what anyone said. I didn't have access to a Ford engineer I found it out the hard way by reasearch and development.

My engines, both of them run butter smooth without any pins what so ever and ASP pulleys, and one of them has been for about 90,000 hard driven miles without a dampener issue. Everytime I reused the pins in the same place as before I got vibrations at RPMs and broken dampeners.

I am going to start collecting every unbroken dampener I can get my hands on and take them all to the machine shop so we can all see just how balaced those crappy stock pulleys are with a washer or piece of metal welded onto it. It's a machined casting, it would have to have an obvious effort to be balanced which I have yet to see on any. Their balance, in my testing, and by common sence, is through the pins.

Call Lee at ASP! Ask the man who's stuff your're going to use. He doesn't want people to have problems with his products. I have met him personally and been to ASP twice. The second time I spent some time discussing this with him and he found the same conclusions I have. He didn't realize the situation when he first offered the SC sets, then when everyone who didn't have their pins removed started breaking dampeners not long after installing ASPs and calling him up to give him grief he looked into it. Now his instructions say to remove them, so why come here and ask someone who runs a steel dampener without pins what you should do with your aluminum one. I have recently acquired a '95 SC of which it's dampener separated (not split, rather the elastomer failes on the newer models) at 155K. I purchased a new dampener from Ford and noticed it was drilled. When I was able to ask Lee why his sets weren't listed to fit '95 he said they didn't use pins and most people don't take theirs off to have it rebalanced with my pulleys like I do. If they have theirs set back to zero they can use them on a '95 (or '94 with a replacement dampener).

I have felt the difference, put the pins in drive it in third gear at a high speed on a good freeway, then go home knock the pins back out and do it again. Then see if you don't trash the pins. In a round about way I've done this exact thing twice.

Ask yourself if the people whose opinions differ have any experiance to back it up. What do they use? I use Ford dampeners with ASP pulleys and don't have a problem.

I respect Duffy and George immensly but I won't back down on something I worked so hard to figuire out and is obvously right to me. I've been advising everyone to do this since I started posting on the net and not one person has ever came back and complained or broke another dampener. Now Duffy found this info that's been there since day one even though you can't buy a new dampener without a pulley attached and already balanced. Now everybodys supposed to imbalance a balanced assembly for a internally balanced engine?

What do you want the phone# of the man who did my balancing work (three times now) so you can ask him, like I'm misleading the world and really don't know what I'm talking about?

Engines By Jeff (est 1977)
Ask for Jeff at (713)-686-3035
He's been in the same location since day one, and has to turn some business away because he and his men can only do so much. He dosen't know anything about Supercoupes other than exactly how their dampeners and pulleys are balanced.

I invite anyone to prove any one of these statements false. I have proof so until then when using a new assembly don't screw with it, if installing an ASP pulley get rid of them. If you happen to find a junk-yard dampener without it's original pulley then put your pins in the same positions on it with your old pulley.

I'm done, don't tell me to chill or relax or any other smart stuff. I am, I don't have a problem, my engines run and I didn't get to ask I had to find out. It's the people who need to know what to do that are having difficulty here with two opposite views expressed by respected members. I've been wrong before and Duffy has been right, the thing is I admit it and change my view. But I don't tell people to do anything for sure unless I am sure of it. The things I don't know well enough to say for sure I acknowledge when saying so, that's it's a theory or opinion. This is the facts I've found and the results I've experienced.

Let's say for a minute that the pulleys are balanced and that the pins were for final engine balancing only. That would mean Ford is now selling assemblys that are balanced for random engines. Some have no pins, some one, some two, some three. Later models are drilled. Whether or not the one your mechanic gets is actually correct for your cars is like 1/10,000. George once said that my three samples were not enough to establish a conclusion. Well then why were they all neutral with various pins, then all out of balance without pins and the factory pulley. The dampeners were all neutral, so what happened to these balanced pulleys we keep hearing about? Can anyone produce a balanced factory pulley? No.

Here's and idea everybody do your own checking, it only cost me $25 a dampener. Then you won't need to ask and you'll find out what I know.


04-11-2003, 04:44 AM
Here are my thoughts:

The engine is internally balanced so harmonic balancer should not have to have pins added or whatever to help balance the crank.

Also Ford sells the complete balancer and pulley assembly ready to bolt on. There is no instructions telling you to move pins from old balancer to your new one.

If I remember correctly, the new balancer I bought from Ford had no pins, but the pulley had a weight added to the inside rim. So that makes me believe that when the cars were made at the factory, they balanced the whole assembly with the pins instead of trying to just balance the pulley it self. The balancer is machined so it would be perfectly balanced. The stamped pulley would not be balanced and would need weight.

It's probably not something to worry about anyway. Too many people running underdrive pulleys on all kinds of engines. If it caused problems or damage you would be hearing about it on every car messageboard.



04-11-2003, 09:53 AM
I feel vindicated:D

I still have my stock balancer and pulley and there is no balancing weight on the pulley, just the pin in the balancer. That is why I made a SWAG attempt at the pins actual use. Engine balance did not make sense, but balancing the pulley did. I did not think that Ford would have spun up the whole rotating assembly on an engine that is only supposed to rev to about 5500. The pin idea makes the most sense, cost wise. It is much cheaper, if you sell the damper as a balanced assembly, to add the pins than weld weights on the pulley.


04-11-2003, 10:16 AM
Wow, Vernon! I don't recall ever having asking you to back down from your opinions and experience. I, too, have certainly been wrong and have changed my mind based on new information, mostly gathered through this board. My only motive is to get correct information out to help other SC owner. I have no vested interest in being correct. (Like when I used to think the "R" code was for forged cranks and the "C" was for cast until I was proven wrong by someone with an "R" code and a Duracast crank!)

In my limited experience with new dampers/pulleys (I have seen two new, total), they all came without pins. This bit of information does not support either line of thought, since it could either mean the damper/pulley was in balance without the pin or it left room for pin installation. I also found a reference in the tech manual where you could buy the pins separatly! This supposedly was so you could put new ones in the new damper without using the old ones. I also have seen about 5 old dampers and have only seen either 1 or no pins installed. That is what I was getting at when I said "small sample" before.

The idea that the damper/pulley is packaged as a unit could just be one of Ford's better ideas. I remember when you could only get a whole $2,000 supercharger from Ford when you only needed a front seal. LOL I'm not convinced those were "matched" at the factory.

What is more compelling in your post, is the actual test balancing of the units. I had missed in your previous posts that a stock unit was unbalanced without the pins removed. Probably because of my bias that I had never seen new units with pins installed.

So it sounds like you have had 3 new units, all with pins from the factory that tested out to be balanced with the damper/pin(s) and pulley all assembled as a unit? Then all 3 showed an unbalanced condition without the pin(s)? Were all these early (89-93) or late model (94-95) units or a mix?

I can't argue with that information, because I have not had any units tested. I would really like to get to the bottom of this, so people do not harm their motors. I know you have busted up quite a few dampers (may just be your driving style, LOL) re-using the pin(s).

One bit of information that I often forget to post is that the flywheel/flexplate is supposed to be part of this balancing equation. There are weights or rivets attached there as part of the final balancing as well. (So, I guess all bets are off when you replace those parts!)

What I worry about now, is that a lot of cars that run the BHJ damper and the stock pulley must have the worst balance of all! Also, people that run the underdrive pulleys, but did not remove the old pins should have balance issues as well. I have not seen widespread reporting of failures in these situations, but it does bear investigating. Do you have any ideas on information we could gather on the various damper/pulley combos that would help us figure out if the pins represent enough of a balance issue to even worry about in installing different damper/pulley combos on older motors? (I agree on new motors that everything should just be balanced at assembly and the whole pin issue is moot.)

Maybe we could come up with a chart of what to do with the pin(s) for the following combos for old motors:

New stock damper/stock pulley
Stock damper/different stock pulley
Stock damper/Aftermarket pulley (assumed to be neutrally balanced)
Aftermarket damper (balanced)/Stock pulley
Aftermarket damper/Aftermarket pulley

We also need to explore if there are any balance differences for the old (89-93) vs (94-95) damper/pulleys. The truth is out there! I'll be the first to acknowledge when I grasp the concept! LOL

04-11-2003, 04:07 PM
my head heard hurts:(, I called the guy that did the balancing said it wasnt off by a gram or so(the one he balanced). I have two more stock pulleys and going see if he can check those also(only if he doesnt charge me to do it:D )

04-11-2003, 04:09 PM
My head hurts too...I still don't know whether to take the pins out or leave them.

Randy N Connie
04-11-2003, 06:27 PM
Whats the difference , installed pin or not installed pin.When the aluminum pulleys
from ASP wobble after you install them any way.Pin or not its not balanced.

I have BHJ BALANCER with ASP pulleys,and all the ASPs wobble big time.I left
the alternator pulley off,but I am sure the alternator pulley would wobble to
if installed.

It looks like I may half to machine my own,to get them right.

The ASP pulley are junk ,NOT WORTH $10.00. They did a good job polishing them,
thats it.

04-11-2003, 10:10 PM
I agree with everything Vernon says. I can't find any flaws in his logic.


04-11-2003, 10:55 PM
Ok, after reading Vernon's post a couple times just to get a grasp on all that information, I will take the pins out of my damper.

Duffy Floyd
04-12-2003, 12:25 AM
As is always the case...each person who reads advice given on a BBS should make their own decisions about what they will or will not do with their cars.

Vernon is correct concerning the 3.8 SC engine being internally balanced. I initally made my original deduction about the pins based in part on the the information he provided and on that contained in the Helms Manual. I assumed I had made the correct assumptions based on that info. I was not looking for any new info concerning this issue but stumbled across the answer during an interview with Lou Williams, the now retired Ford Development Engineer responsible for the much of the work done on the Bonneville SC project. Based on that input I provided the information given to me.

The 3.8L engine as originally developed by Ford is inherently unbalanced. That is just a design feature of a 90 degree V 6 engine. Some versions were made with balance shafts to try and mask those vibrations. We are all aware of the fact the SC's are equipped with fluid filled motor mounts to isolate the vibrations from the feel of the driver.

The information provided by Lou is very plausible and based on his direct knowledge and experience in this arena I am not going to question it.

All engines produced were test run at the factory following assembly and prior to shipment to Lorain for car assembly. The balance pins were installed along with rivets in the flex plate or pins in the flywheels as a final fine tuning of the balance or dynamic balancing of the engine assembly. This is required given the rotating mass of the engines are made of many pieces which may fall within manufacturing tolerances for weight but when put together in an assembly result in less than desirable results made worse by the inherent imbalance of this design of engine.

So the bottom line in my mind...the dampers fail cause of their crappy design. The AL hubs fatigue fail over time.

My advise is if you install aftermarket pulley on the stock damper ...leave the pins alone. If you balance your engine during a rebuild and chose to stick with the stock damper (dumb move) pull the pins since your balancing efforts will result in the best result possible and the pins are not going to help. If you replace a broken damper with a new Ford unit....do as the Helms Manual says and if you have them, transfer the pins from the old damper to the new one in the same relative position. If you install a BHJ right now there is no provision for pins so you can't install them. You may experience a tad more vibration with the BHJ.

04-12-2003, 12:41 AM
How do you balance an assembled engine?


Duffy Floyd
04-12-2003, 01:53 AM
We as the end user can't. That is why the balancing is done part by part.

I would assume (not ever asking the question) that the process would be similar to that used to dynamically balance a tire. Spin the rotaing mass by running the engine it at a given RPM and detect the vibrations created by the imbalance and compute where and how much to "weight" the rotating assembly. This technology could be close to that used to detect and solve NVM problems made by Vetronix Corp. It allows location of the problem after scanning for resonant frequencies after a short drive. Optical scanning tape is applied to the rotating driveline components and that vibration source can be located.

How about one for you...really think the addition of a small pin or two is going to throw off the balance of a rotating mass of greater than 60 Lbs so much you will break the damper due to excess vibrations in a forged crankshaft that rarely if ever sees anything over 5500 RPM?

Next time I come to Houston I will bring the tape of the interview and you can listen to it for yourself.

04-12-2003, 01:58 AM
I'm not doubting, just asking a question I don't know the answer to.

How much does a pin weigh and how far from the center is it located?

Bring it I would love to watch it.



04-12-2003, 01:33 PM
Jeff, this pic may help. It is the backside of an early style damper.


The circle is around one of the 8 holes that are evenly spaced around the steel damper ring. The holes are 7.5mm in diameter and are on a 132mm diameter around the damper. This particular damper has no pins. I believe the pins would have to go in from the front (not the picture side) or they could interfere with the crank sensor ring or even the crank sensor.

I thought someone had previously posted the weight of the pins, but I could not find that information. Maybe Vernon can shed some light here with all of the research he has done.

The circled area at the top is where metal has been removed from the damper to assist in balancing the pulley.

04-12-2003, 03:31 PM
I'm going to be busy most of this weekend so I may not be able to address everything yet. I believe what Duffy found out from the Ford engineer to be true. However unless we disassemble our motors and have the rotating assembly dynamically balanced there's no way we can duplicate this when changing pulleys or both. It seems to me that the majority of balancing the pins produce is for the factory pulley, not the internal engine fine tuning. So when replacing the factory pulley with a ASP or any other neutrally balanced piece we should strive to maintain a total nuetral balance. If we reinstall pins or leave them in place with a neutral pulley we create a worse imbalance than without them. I believe the internal balancing from Ford to be closer to zero than the pulleys. That would explain why Ford sells them this way.

George, you mentioned that you've bought two without pins. Were these for the later model DIS like on your nice car? Those pulleys no longer used pins for balancing, instead they were drilled out in the proper locations to achieve a balance.


04-12-2003, 04:09 PM
internal balancing is just that. the dampner and crank pulley are not in the equation when the motor is balanced. they are nuetral.
Quality aftermarket pulleys and dampners should also be nuetral, even more so due to the fact that manufacturers are catering to a vast spectrum of motors in every possible configuration and mechanical condition. That being said, an SC motor, in good overall condition is balanced from factory, and utilizing good quality aftermarket units like the ASP pulleys or BHJ dampners will not harm our applications. They benefit due to superior design, lower weight and increased durability. To clarify, I use the term dampner because on an internally balanced motor needs no harmonic balancer, it requires a harmonic dampner. It might seem like semantics, but the difference is there. A dampner doesnt serve any balancing function, its purpoce is to eliminate harmonic vibration, whereas a harmonic balancer (external balanced engines) serves to complete the balancing of the motor.
To simplify, if your using a NEW stock unit (complete with pulley), ignore the pins.
If your using aftermarket pulleys and original balancer, remove the pins.
If your using a BHJ, ignore the pins.
If your using a junkyard unit, use the pins and have a machine shop double check the balance.
Ideally any time you monkey with the dampner, have it inspected by a competent machinist, he can detect possible damage, problems in balance/nuetrality, etc. its cheap insurance.
Also, you would be ill advised to use a junkyard dampner on an SC, given the problems with delamination and self- destruction of the stock units as they age.
Hope this post helps in some way

Randy N Connie
04-12-2003, 06:19 PM
The pin from my stock 90 sc with auto protrudes out the front of the balancer.
If you are standing in front of the SC looking at the installed balancer you will see the pin.

On my stock balancer,with the balancer sitting front down on my rotory table on top
of my milling machine.With the top dead center mark on 0 degrees on the rotory table.
The pin location was 265 degrees.

And the stock balancer had a drill hole about 300 thousandth deep.at 112 degrees.

the balancer pin weight was 9 grams & 7 tenths.

When I installed my aluminum ASP pulleys they were wobbling. So I had to
loosen the bolts , put a dial indicator next to the pulleys,then rotate pulleys
and tap on them untill they were centered,then I snugged them down.

04-12-2003, 07:08 PM
Thanks for info, Randy!

Vernon, my nice car is an 89, so all of the new balancers I have seen without pins were the early style.

One often overlooked part of the engineer's info on the pin was that they were used in conjunction with weights or rivets in the flywheel or flexplate.

Jim Cook
04-14-2003, 12:28 AM
The debate rages on w/o resulting in clear consenus. Call me foolish, irresponsible or just plain lucky but I've gone over 330,000 miles on three engines, with an ASP crank pulley in service. Mostly highway miles in the 2500-3000 RPM (rear end ratio not given to protect the guilty) and the pins were never removed, with no problems experienced. In fact, one pulley set has been in service on two different engines to the tune of 279,000 miles. So, I'm leaving them in and should a damper fail between now and the time I get around to replacing them, I've got 3 BHJ's on hand just in case.

03-08-2011, 12:33 AM
so has anyone come up with the right way to do this i have a set of asp pulleys im going to put on what should i do knock the pins out or leave them in i have a stock hb.

03-09-2011, 11:56 PM
This is the section of the repair manual that has caused so much confusion all these years:

Engine Front Cover (assembly/disassembly instructions)

Step 15.

If the crankshaft damper is being replaced, check if the original damper has balance pins installed. If so, new balance pins (E0SZ-6A328-A or equivalent) must be installed on the new damper in the same position as the original damper. The crankshaft pulley (new or original) must also be installed in the same relative position as originally installed."

Now if you if you take out one word, "new" it validates everything I've said.
Engine Front Cover (assembly/disassembly instructions)

Step 15.

If the crankshaft damper is being replaced, check if the original damper has balance pins installed. If so, new balance pins (E0SZ-6A328-A or equivalent) must be installed on the new damper in the same position as the original damper. The original crankshaft pulley must also be installed in the same relative position as originally installed."

Now why does this whole sections validity come into question? Neither now, then, or ever did Ford sell new dampers or new pulleys for these engines separately. So this instruction was never to be followed after it was printed in 1988. Also the damper and pulley can only go together correctly in one position. This is due to the fact that one of the four bolt positions is just slightly offset. This is so the balance will always be maintained and the TDC notch will always be at #1 TDC. So then the manuals mandate that the pulley must be installed in the same "relative position" is proof that the author wasn't exactly the expert on what was to be produced. Now it is possible to make the pulley go onto the dampener in the wrong position if you're willing to force the bolts. Read Randy's mis-informative rant post again to see what happens when you do this and see it through.

The answer to your question is that if you're going to install a billet aluminum pulley onto your Ford damper you would be better off to knock all the pins out. Read my old long post and this new one over and over again until you get it and you're damper will live a longer and happy life.


03-10-2011, 02:16 AM
i installed asp pulleys today and i had the same concern so i called them and the guy said since my stock hb is so old to leave them in and i must say they work fine!