Harmonic balancer bolt size on Vin. C engines, 25 mm, 26 mm ?? Do you guys use NO-SEIZE or Loctight on reassymbly of the Balancer Bolt? Thanks

its SAE. we had to buy 6point impact sockets and a 24inch breaker bar to get the thing off with a prybar in the flywheel. hated every minuter of it. it takes 2 people, so be prepared. cant remember exact size. sorry

For me, removal requires a standard breaker bar and an impact socket and is performed from the driver'* seat. Installation is a little more difficult. Loctite blue is not a bad idea but make sure everything is clean and the bolt goes in all the way by hand first.

to remove mine I had to put a stop in the flywheel lo prevent turning. then I used and impact to remove. But once it is out you have to get a newbolt. its a one time use bolt


Loc-tite.. no...figure if it has to be out again its time to sell and or I did something wrong. cause the chicago pnumatic impact will remoe anything

Does anybody reuse their Harmonic Balancer Bolt? or do you throw them away as gm suggest? Have been told that the Harmonic Balancer bolt is metric and SAE anybody know for sure what size this bolt is on a Vin C engine. Thanks

I've found that engine bolts are all Metric, while Cylinder Head and Exhaust bolts are SAE. I have not tackled the harmonic balancer.. but if it stops snowing sometime today, I can go out and see.. I think I have up to 25mm.. and the SAE equivilant.

If GM says you cannot reuse the bolts, don't reuse them. If they don't say anything, then reuse them. The Head Bolts are "Torque To Yield" bolts, which are a one time use only bolt [both my FSM and Haynes manual say this]. Check your manual [FSM first, Haynes or Chilton'* second] to confirm. If you don't have one, go pick up a Haynes or Chilton'* manual, they are like $10, and they have good info.. well, for the most part [many will disagree with me].


-justin

For my cars, I keep a Haynes or Clymer in the car (does not take up much space) and the factory manual at home. The small manuals are up to anything I can do while travelling.

The Reatta people (www.reatta.net) have gotten permission from GM to scan and post their factory manuals and the P&A online. Since the driveline and HVAC are identical to the Bonneville this is a valuable resource on the road.

I have the factory GM manual but it makes no mention of the size (metric or SAE) of the bolt, just mentions that it is a disposable bolt. I just want to have the right size socket on there when I crank over the engine to release it and not to strip it out. Oh man I hate to even think about that. I am assuming that the bolt is a left to loosen thread design if anybody knows, this also I would greatly appreciate. Thanks

Just try some sockets.. if it has a lot of play, it'* not the one you want. If it has only a little play, then you are set. We are currently going through a blizzard.. or something like it, so I cannot go out to my car to check anything. Another member may be able to, however.


-justin

Iff'n I picked up the right bolt, a 15/16" six point impact fits snug. That would be 23.8 mm and I do not have any 24 mm sockets or wrenches. Heck I am still looking for a 18 inch or two foot long 18 mm.