Guest TBroZ Posted March 10, 2003 Share Posted March 10, 2003 Last week I put in a 30 lb steel flywheel (from PAW). I bought the car non running and without a usable trans, but after getting it running, the motor did rev smoothly. It had in it an aluminum flywheel, weighed may 10 lbs. Now that the new flywheel is installed, along with the T5 tranny, I notice during revving, at about 2K rpms or so (guessing; no tach.), there is a significant vibration, like something is off balance. I can't think of how it could though. This happens even if sitting in neutral, so it couldn't be the tranny. It's a little more pronounced while driving, which makes sense...being that there's a load to amplify the effect and transfer it into the driveline. Any ideas? TIA, Terry Quote Link to comment Share on other sites More sharing options...
denny411 Posted March 10, 2003 Share Posted March 10, 2003 Is it the right flywheel? maybe they shipped you an externally balanced flywheel. I would recomend getting it checked or balanced before puting any more miles on it. You could tear up bearings in a hurry with that much vibration. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 10, 2003 Share Posted March 10, 2003 I just checked the part number in the PAW catalog (460300) and it says that without counterbalance weights, it's neutrally balanced. But maybe I need a counterbalance weight? How would one know if it needs the counterbalances? I'm thinking it does. I see that the aluminum flywheel has balance drill holes. While ordering from PAW, I told him which motor I have and he recommended the 460300 flywheel...didn't mention anything about counterbalance weights. Terry Quote Link to comment Share on other sites More sharing options...
denny411 Posted March 10, 2003 Share Posted March 10, 2003 If it`s for your 327 it shouldn`t need counter balanced. I would recomend taking it to a good machine shop that balances flywheels and have it balanced to match the old one. I suspect the old rotating assembly was balanced together and this could be your problem. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 10, 2003 Share Posted March 10, 2003 denny411, are you saying that they would balance the flywheel while on the motor? Terry Quote Link to comment Share on other sites More sharing options...
denny411 Posted March 10, 2003 Share Posted March 10, 2003 No, they can check the balance of your old flywheel and balance your new one to match it. You would have to remove it and take it to them. The other option would be to disassemble the bottom end and take the pistons,rods,crank,rings,harmonic balancer,and the flywheel to them and have the entire assembly rebalanced. Doesn`t sound like a lot of fun does it? flywheel balancing could be compared to the process of wheel balancing. It`s basically the same principal. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 10, 2003 Share Posted March 10, 2003 I spoke with a guy at the machine shop and he says that the 327 is internally balanced, so my neutrally balanced flywheel should be okay. He says that the balance drillings in the old flywheel could be just to get it to neutral balance. He did say that it could be the pressure plate. I guess I will be pulling the whole f'n' thing apart again and have the flywheel and pressure plate balanced. Terry Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 11, 2003 Share Posted March 11, 2003 TBroZ; You sure you have a 327 and not a 400? And why you drop the alum. wheel anyway? SPIIRIT Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 11, 2003 Share Posted March 11, 2003 I'm not positive, but the guy who sold it to me said it was. I didn't have the receipt for it, but gave me the Sig Erson cam spec sheet...made for a 327. I had to get a different flywheel for the new clutch...required for the T5 trans. TK Quote Link to comment Share on other sites More sharing options...
denny411 Posted March 11, 2003 Share Posted March 11, 2003 The easiest way to tell would be to look at the harmonic balancer. The 400 ill have a notched section on the back side of the outer ring. A 327 cam would physicaly fit and work in a 400, so that`s not a clear indicator. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 12, 2003 Share Posted March 12, 2003 Thanx for your answers. OK, by now I would have the clutch/pressureplate assy. and flywheel out and being balanced as a unit, but not before I was darn sure I had a 327, crank in there reguardless of the cam deal. As already said, a 400 crank has external balance, if the crank is not a 400 and considering all you have stated then the only thing left is the changes you made. I am assuming that you did install a new clutch/pressureplate combo which was purchased as a balanced unit? I am done here.....LOL SPIIRIT Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 12, 2003 Share Posted March 12, 2003 The flywheel and pressure plate were dropped off at a balance shop yesterday, along with the original flywheel and pressure plate. He'll be checking the balance of the original flywheel and the new one, then look at the pressure plates. Since this statement, "The 400 ill have a notched section on the back side of the outer ring.", isn't clear to me, I will post a pic of my harmonic balancer tonight. Terry Quote Link to comment Share on other sites More sharing options...
denny411 Posted March 12, 2003 Share Posted March 12, 2003 If it turns out to be a 400, it would be one heck of a bonus. Even with the trouble you`ve had. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 12, 2003 Share Posted March 12, 2003 Yes, it would, but I sincerely doubt it. Either the original owner's memory is f'd up, or GM gave him a different motor than he asked for. My confidence level of it really being a 327 is pretty high. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 12, 2003 Share Posted March 12, 2003 I just got a call back from the shop that's checking the flywheel balance...no good. The original flywheel has a perfect balance, he says. The new McLeod flywheel..."couldn't be more out of balance". I've put in a call with McLeod and he's conferring with the balance shop as we speak. TK Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 13, 2003 Share Posted March 13, 2003 Amazing finding.....what a mess. Of course they are eager to reimburse you for your inconvenience?.....LOL. Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 13, 2003 Share Posted March 13, 2003 Got the flywheel balanced. McLeod wanted me to send it back of course, so they could do their own analysis. No. I told him that I need this thing balanced and back in the car, and with shipping costs, yadda, yadda, yadda. Sorry, I never say that, but I hadn't heard it in a while. Anyway, McLeod agreed to pay for the balancing. $26. I paid $52 total, to check the original flywheel. It wasn't as "far out of balance as could be" as he originally told me, but off. I've got it all back together, with only the driveshaft to go, and to fill the trans back up with ATF. I'll give a report of the hopefully....smoooooth running motor tomorrow. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 13, 2003 Share Posted March 13, 2003 I'll say one thing for sure, you are fast with the wrenches! I wonder if 2000 rpm is the "sweet spot" for engine vibration? I read that exaust drone peaks somewhere in that range. I still find it hard to beleive that they messed up with a stock flywheel.....Hmmm!!! I am now entering a Post which will have a long run because I have a '70 Z on stands and stripped for mod to a street rod (big time) and have many questions to hash out. Maby see you all there. I will still follow here tho' Quote Link to comment Share on other sites More sharing options...
Guest TBroZ Posted March 13, 2003 Share Posted March 13, 2003 I'm definately an Olympic hopeful...should car repair become an event. Actually, I'm excited and obsessed, so I'm coming home from work, immediately gettin' at it...quit last night at 9 p.m. I know with my GN, that's exactly right...droning at 2K rpm. This wasn't droning though...purely vibrational...more shake-tional really. How 'bout, vishaketional. That's it. Yeah, the guy at McLeod was very miffed. And really I am too...it looks like a very precision piece. I mentioned the counterbalance hole provisions, and he tells me they're within spec for zero balance. Look at the pic, and you can see the new drillings are exactly opposite them though...hmmm. But he said he hasn't had a single call on them 'til mine. I'm crossing my fingers that this will fix the vibe. TK Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 13, 2003 Share Posted March 13, 2003 I love tools, they pay for themselves. I have discovered that our car work is a "Labor Of :ove" and it is almost as good as sex....LOL! Yes, I fail to eat and even to smoke when I really get into it and Time?.....what's that? Ya, the pic shows maby 3/4" drill/5 places. The guy removed signifigant weight there. It was just your turn to be the goat. About the "drone": Apparrently 2000 rpm is creating a sound vibration that resonates max. there reguardless of the legnth of the exaust etc.. So since all V8's seem to have this I was figuring it must be fundimental to the engines themselves. Then if the whole car has a sympathetic vibration in that area it would also pick it up and amplify it into an even more beautiful sound to carress our ears.....NOT! Overall, the bad news is that dropping the alum. wheel cost you considerable accelleration but of course heavier gives smoother shifts. Quote Link to comment Share on other sites More sharing options...
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