Harmonic Balancer Wobbled now Loose Bolt

[msmithmmx]

I was starting the HG job on my 96 2.5 with 190K (engine out). I ran into something, I used my impact gun to remove the bolt that holds in the harmonic balancer. I noticed that it took next to no effort from the gun to remove the bolt. That’s when it all started… 2 things I noticed. The keyway on the harmonic balancer is shot and there is a hole on the plastic timing belt cover where the balancer had warn into it at some time. I was thinking no big deal at this point….. Now I noticed what my question is about, the bolt screws back in but it has a lot of play (I can wiggle it all little) in any direction. I can screw it all the way but for the last turn and it still has play. Not until I screw it down does it get tight. I think this is my problem. The bolt does looked stretched around the grooves. Needless to say I went and ordered a bolt from the dealer. Could I chase the hole or tap it out if the new bolt has play if so does anyone know the size of the chase or tap I would need. Note: the bolt goes in about a 1/2 inch before there are any threads, this appears to be normal because I do not see any worn threads, could anyone confirm this for as noraml. Has anyone ran into the overall problem before.

[lostinthe202]

How much play are you talking about? Most bolts will wiggle a little until they are tightened down. How do the threads on the bolt look? If they aren't visibly munched, then I would say you're probably fine. What I would expect if the bolt had gotten loose and the pulley was wobbling around, is that it would distort the threads making it hard to remove/install.

 

If it turns out the bolt is too loose, running a tap in won't do any good. A tap will straighten out threads, but it cant make them tighter.

 

I don't know if the threaded end of the crank is hardened. If it is, you won't be able to drill/tap it. If it isn't, then I suggest taking out the radiator so that you can be sure you're drilling and tapping along the axis of the crank so that your new threads will be straight. I'm sorry, I don't know the size of the thread, but I'm sure someone here does.

 

As for the Keyway, you say the keyway on the pulley is shot, how 'bout the keyway on the crank and the key itself?

 

Pics would help if you can take some.

 

Good Luck!

 

Will-

[CNY_Dave]

I wonder if they make a helicoil kit that large?

 

Tapping the hole for the kit would be a challenge.

 

 

I'd say the best bet is new bolt, new (or good used) balancer, and some good locktite for the bolt.

 

If the (new) balancer slides all the way back into position and has some wobble, yer crank is probably done. In that case, you could conceivable locktite the bolt and the balancer (hello loktite sleeve retainer!) to salvage whatever miles remain in the engine, but you'd never get the balancer off again.

 

 

 

 

Dave

[hohieu]

The keyway on the harmonic balancer is shot and there is a hole on the plastic timing belt cover where the balancer had warn into it at some time.

So I guess you need to find a replacement crankshaft pulley as well. Is the Woodruff key intact?

 

Not until I screw it down does it get tight.

As already mentioned, this is pretty normal to have a little bit of play. The new bolt may help. So long as you can crank it down to the specified torque, the threads are fine.

Could I chase the hole or tap it out if the new bolt has play if so does anyone know the size of the chase or tap I would need. Note: the bolt goes in about a 1/2 inch before there are any threads, this appears to be normal because I do not see any worn threads, could anyone confirm this for as noraml. Has anyone ran into the overall problem before.

If even the new bolt doesn't go in smoothly, chasing the threads isn't a bad idea. The size is M14 x 1.5 -- same size but different pitch as spark plugs, which are M14 x 1.25. You're right -- there are no threads in the first 1/2 inch or so on the crankshaft snout.

[nipper]

REad the related posts at the bottom of this thread for guidance.

 

nipper