wp94gt

I just recently found out that my harmonic balancer is screwed the car vibrates really bad specially from 4 to 5 thousand rpms, also its been running that way since i pretty much got it i thought it was the mounts which were bad and just had those replaced I'm asking because I hope i didn't cause any damage to the crank. also how difficult is it to get fixed and costly since I probaly won't do it myself thanks.

94 mustang gt

bobby

ya it def. sounds like its the balancer, u can get a new one for like 80 bucks prolly, it isnt that hard u just need a gear puller, u can rent one from autozone

roundman

you need a special puller to remove the harmonic balancer and you can rent or borrow one from AutoZone stores. it's not a hard thing to do to change it, just remove the drive belt and pulley, then use the tool to pull the balancer off and install the new one. then install the pulley and belt back on and you're done.

87mustang347

how bad is it to run ur car like that because i juss found out that the balancer i got on my car is no good for for it either and it vibrates from 4 grand to 5 grand..im gonna change my balancer and my flywheel to 28oz but what effect does it have on the motor

roundman

you cannot just change the balancer and flywheel to 28 oz because the crankshaft was balanced for 50 oz and this will really cause a lot of vibration which will damage the crankshaft. you should replace the balancer ASAP as this is damaging the crank and bearings right now. the crankshaft, balancer, and flywheel/flexplate is balanced as an assembly and you cannot just go changing the pieces out with different balanced parts or you will destroy the crankshaft rapidly. the older 302's used a 28 oz imbalance while the newer ones are 50 oz, so unless you know you have an older crankshaft balanced for 28 oz, I would not change the balance on the balancer or flywheel. the harmonic balancer on any engine is a damper to reduce the torsional stresses that are constantly trying to twist the crankshaft backwards and forwards as the various cylinders fire on the power stroke. these torsional forces can actually twist the crank and break it if they are not dampened properly by the correct harmonic balancer! and since the force generated by these torsional vibrations increases with the square of the rotational speed, when the rpm of the engine doubles, these forces increase 4 times and can get to be tremendous at higher rpms and they can do significant damage to the engine rotating assembly.

87mustang347

well if i took the stock flywheel and balancer off my 302 and put it on my 347 and am gettin alot of vibration at 4g then i must have an older crank. plus i called up ford and they said to get a 28oz balancer and flywheel

roundman

what were you able to tell them about the crankshaft that allowed them to tell you to go with 28 oz?

wp94gt

I'm pissed because I just bought the car in april and their was no vibration I was aware of. I just looked the other day and the balancer is shaking violently at idle also I think the crankshaft seal is broke because it seems to drip oil from the crank pulley. Is their hope or am I screwed and the crank is destroyed, and I don't have the money to fix it so i'll probaly junk it.

chriscindy6369

Go with the 28 oz flywheel weight if you have a stroked motor. 50 oz if it's stock.

roundman

Don't give up hope just yet! Just get a replacment balancer from the junkyard if you have to save some dough and while you have the old one off the crank, remove the old front main seal and install a new one before you install the balancer. Just make sure to get one off a modern 5.0 HO engine. You will need the proper tool to remove it, so get one before you go to the junkyard.