harmonic balancer

[68glad]

A couple weeks ago I sent my harmonic balancer in to have it rebuilt. The one I got back is not the one I sent in. No part # on this one and the small 1/2" holes on the edges are drilled in different spots. I am currently rebuilding my motor and will have the rotating assy balanced. Are balancers drilled from the factory to match the crank or are they drilled to bring them into a certain spec? Should I ask for my balancer back or am I overthinking this? Thanks

[serehill]

It is part of the rotating assembly. I take my flywheel & HB when I have my engine set up. Flywheel & HB when they balance. It won't matter that it's different.
I wouldn't trust a rebuilder to set mine up. I always replace with new.

[68glad]

Ok, thanks for calming my nerves. It is definitely an amc balancer but with holes in different spots I didn't know if that would cause a lot more work to balance it all. On Monday they told me they were "cooking" it and would send it back on tues/wed. So when I opened the box I was suprised to not see mine.

[serehill]

Could be several reasons they changed it. Have your engineer check against what he's setting up. You'll be OK. Good luck with the set up.

[tgreese]

The balancer is an off-the-shelf part. AFAIK there's no tailoring of each balancer to the engine at assembly time. So it should work fine - as long as you have the part for the right application. Year to year could be a different appearance, even if the function and balance is the same. Different displacements use different parts - a separate PN for 304, 360 and 401. So you need the part for your displacement. Could be you have a part for a different displacement that's been rebalanced for your displacement - 401s are much less common than 304s or 360s.

Have you contacted the rebuilder? Which rebuilder? A place like A-1 Cardone probably takes balancers from stock to replace common cores. There are other places that will rebuild and return your core. You're pretty much SOL now if you sent your core for exchange and want it back - at the rebuilder, cores go in and there's no tracking of a specific core beyond its app. Did you take pictures of the original? You could post up pics of the original and the replacement.

[serehill]

That's why I take mine in to ensure they are a match. Yeah you absolutely don't have to. I built a 401 years ago with a brand new HB & flywheel. I found the flywheel to be wrong. The fun thing is you don't know what it is so the process of aggravation /elimination finally found it. A vibrating engine can be many things. It should have worked fine & the numbers were correct on it. Took it to the machine shop I used for years & still do. They corrected it by reweighting it. They recommended you confirm a match. Yeah more money for them. If that creates less risk for me I'm good. Better safe than sorry. I have them checked now. I don't take them to have them modified. I take them to ensure they are correct & OK since they are part of the rotating mass it doesn't hurt. Overkill yes but most race engines are set up that way. Easier than pulling an engine. In this day of mail order parts & goofy counter guys, & bad quality control. I'm not gifted enough to just look at it & determine they are right. Everyone has assumed a part was good that wasn't new or not. Assumption is the mother of all screw ups. Dealers choice.
No doubt it can be done either way. They cost of balancing is ten times what checking these parts cost.

Just my opinions no right or wrong & the way I do things. An engine builder used to live next door to me that built some really good race engines. He told me he's lost more money with bad parts than any single thing. If you balance the rotating mass make sure the accessories don't counteract that.

[68glad]

Yes I did take a couple pics but not very good ones. No part # visible on the rebuilt one. I sent it down to damperdoctor in redding,ca. Mine was #3216085. It is for a 4 bolt pulley and it listed in both of the 4 bolt options on their site. The one I got has no # anywhere but is definitely amc i'd say. The black one I got has a 1/2"x3/8" deep hole drilled at the 9:00 position on the bottom side also.
http://damperdoctor.com/index.php?route ... path=33_85
mine:

[tgreese]

Parts book says that a 3216085 is for a 1974 401 only. '75-78 uses a 3231032. Parts book also shows that the 3216085 is superseded by the 3231032. You were required to order 3 other part numbers to complete the installation of the superseded PN - 3230155 (washer), 4005748 (bolt) and 3229831 (??).

[68glad]

Parts book says that a 3216085 is for a 1974 401 only.

Which is possible. The engine was out of a 75' Cherokee (registered 75' anyways). Hmmm........should I see about getting mine back or just go with this one since it's getting balanced anyways? A part number on this one would sure be nice though.

[carnuck]

3229831 is the key for the crank

http://www.factorychryslerparts.com/pro ... 29831.html