Finally got to fire up my completely rebuilt 302 the other day. To cut a long story short, I think I have the wrong weight flywheel and harmonic balancer. I ran it for several minutes on tickover, until hot, which felt OK, plus a few blips on the throttle, which is when the shake became apparent.
What concerns me is that some oil leaked out of the front crankshaft seal, even tho its all brand new.
Could I have wrecked something already?
The oil leak on the front crankshaft seal may be from a worn shaft on the HB. Did you replace the harmonic balancer or is it the original one??
If it's the original one, in time a grove will form on the shaft of the HB where it contacts the seal. If you overlook the groove, when you reinstall the HB with a new seal, the new seal will leak since there is a gap between the seal and the HB shaft.
You can get a sleeve kit for the HB shaft which a few people have had luck with but I don't mess the sleeve kit and just replace the HB. Chances are if it's the original HB the rubber is dried out anyway so its time to replace.
Even if the HB was new, the leak could also be from the seal being dry if no oil was put on the seal surface before the HB was installed. if this was the case, on initial start up the seal could have been damaged (melted / burned / scored / deformed, etc) and it leaked.
The HB was new, hence it may not be the right weight. The engine came to me with nothing, so I didn't have an old HB or flywheel to go by.
I did smear oil on the HB when I fitted it.
Is this a stock crankshaft?
If it is, do you recall or have pictures of any stamping on it?
That may help determine balance.
At front of crankshaft on counter weight.
The crank is stock, but do not recall any markings.
My concern is, could I have wrecked the main bearings, causing excessive play, and that is why the oil leaked? It's hard to imagine such damage so quickly, but the way my luck has gone so far with this build, who knows!
I doubt you destroyed the engine. But you'll never be sure you have the right weights until you remove the oil pan and record the numbers on the crankshaft and connecting rods.
Chances are your leak at the front cover is the result of it not being "centered" on the balancer when installed.... that, or the balancer installed with the seal and sealing surface "dry" or, finally.... the spring behind the seal lip knocked out during balancer install.
Here are some pics of my crank before the engine was rebuilt. Can any of you eagle eyed experts spot anything that tells you whether I should have 28oz or 50oz flywheel and harmonic balancer please?
I have a real dilemma now! I had accepted your comments and observations about my crank, and it had all reinforced my thinking that I need to swap my flywheel and HB from 28oz to 50oz.
Now, something has thrown a spanner in the works, and put a huge doubt in my head. After several hours work, I managed to remove the flywheel (engine in car, on axle stands!) and when I looked on the back, the counterbalance weight is missing. It appears to be a bolt in type, and there are two holes, but no weight. My delema is, is the missing weight the sole cause of my shake, and it is a 28oz crank, or is it a 50oz crank, and this just added to the problem?
I need as many opinions on this as possible please, as I cant face putting it all back together wrong.
The pic shows the rear face of the flywheel I've just removed.
This guide suggests, if my casting reads E0AF D3C, that its a 1980-84 302. If 50oz was introduced in 81, it could still be either? View attachment 757127
Definitely you have the 50oz crank. Absolutely missing that weight is going to cause vibration. Put the correct weight on the flywheel, button it up and see if it still vibrates. If it does then you have the wrong balancer designed for 28oz. If it runs smooth you've saved yourself a little time and money.
Do you have the original flywheel that came on the motor? The reason I'm asking is because at the factory the whole rotating assembly is balanced as a unit. Take the flywheel that came with the motor along with your new one with the weight and have a shop exactly match the old one. I had a slight vibration with mine, took it off and had a shop match it to the old one. It wasn't that the new one was balanced incorrectly it was more that it didn't exactly match the factory flywheel which could have been out of spec. Anyway I'm glad I did. The engine runs smoothly now. There was a 10 gram difference between mine
I don't have the original flywheel or harmonic balancer. I have a weight on order to convert my Pro-Street harmonic Balancer from 28oz to 50oz. I've bought a 50oz cast iron flywheel, but I was worried all this could be a big waste of time and money if all I need is the missing 28oz weight for my existing billet steel flywheel (PCE229.1009).
You are certain it's a 50oz crank from what you can see in the pictures?
Cool. So its definitely 50oz.
I'm in the UK, so not easy to get a weight. Can anyone tell me who is the main dealer for that make of flywheel over there? I dont think anyone sells them over here
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