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I just had my engine replaced with a used motor (84 F250 460). I plan on rebuilding the original but needed the truck for plowing this winter, so I found a decent 460 and had it swapped out. I've had the truck for a couple of days and have been working out some bugs (choke, power steering, etc.), but one that I'm not quite sure what the problem is.
The engine has a bit of vibration in the upper rpm's. It occurs when sitting with the clutch in, or when driving. It is very consistent. The guys that did the swap pulled the flywheel from my motor as I have a manual shift tranny, and the new (used) motor came from a automatic. They did not swap balancers.
Could this be the problem or am I looking at a timing issue?
Vibrations can be caused by many things. First thing I'd check is the timing. If it's out, adjust it. Here's where it can get fun, how-ever, as the harmonic balancer's outside ring can "slip" when the rubber donut dries out, and it makes accurate timing near impossible. That might be your problem. Could also be caused by weak valve springs, worn timing chain, out of balance flywheel, worn wrist pins or bushings, etc. Using a stethescope might help narrow down the locality of the vibration a bit. From the cab it will just sound like a general noise.
Well, the vibration is really felt, not heard. I'm concerned about engine damage if the balancer or flywheel is the problem. Although not severe I would like a bit of life out of this engine, at least for the next six months.
Ditto with RR4E on the harm. balancer.I'm not possitive but I think somewhere down the line 460's switched internal/external balance,depending what yr. motor you have this could be a possibility.But like I said,not possitive.
I talked to the guys who swapped the engine and they want me to pull the harmonic balancer of my old engine and let the install it on the replacement. They said both engines were balanced externally. So, I'll go ahead and give that a shot. Thanks for the help!
It could be the replacement has a slipped outter ring on the harmonic balancer. If both engines are externally balanced the flywheel should be fine, and replacement of the harmonic balancer might cure your problem. If it doesn't look further into it with a stethescope to isolate the source.
79 and older 460's were neutral balance motors.
The spacer behind the harmonic balancer was just a spacer.
The balancers were all the same.
The automatic and standard flywheels had no weights or uneven casting to add weight!
80 and newer 460's were externally balanced.
The spacer behind the harmonic balancer had a huge weight cast into it.
The balancers were the same as the older motors.
The flywheels had weights added to them (auto) or were weighted during forgeing (manual)
You must determine what year motor you have and balance accordingly!
Steve G.
Both engines are 84's. My flywheel was swapped over, but not the balancer spacer. This has got to be the cause of the vibration. The balancer on the old engine has the weight, but not on the new engine, so I'm going to swap it over and give it a test.
This smells fishy!
Lets determine what year motor you installed.
Stamped into the block above the starter is the casting# which tells us the year the motor was designed.
I just pulled out a 85 460 block and checked the #'s
D9TE-AB
This tells me that this block was designed in 1979
D=70's 9=79 T=truck E=engine
Any 460 motor with this date or newer is EXTERNALLY BALANCED which means weighted crank spacer and flywheel
Let us know
Steve G.
Well, it did sound a bit fishy. So I did some research and contacted the original owner of the new engine. I was wrong, it is a 78 motor. Judging by the info you listed, the replacement motor was neutral balanced, and my original motor was externally balanced.
So... If they used my flywheel on the neutral motor but not the balancer spacer, I should expect to have a vibration. Correct?
My question now is, can I swap over the balancer spacer and expect to have it balanced or am I looking at something else?
Yes, you will have a vibration!
If you installed the 84 balancer spacer w/weight it will exacerbate the vibration.
This problem can ONLY be corrected by installing a neutral balance flywheel!
I know this because I did the exact same thing you did!!!
Good luck
Steve G.
Well, I've done some more research into this replacement motor. The original owner could not remember exactly what the heck it is so I took 8 Lugs advice and checked the cast number. D4VE-AA
This tells me it is a 1974 Lincoln. The Ford dealer I called told me this engine is externally balanced. But there is no weighted spacer behind the harmonic balancer on it. The guy I talked to at the Ford dealer could not confirm the balance type.
Can anyone confirm whether I need to swap the flywheel with a zero balance flywheel? I don't want to go through all that trouble if it is not the problem. 8 Lugs, any suggestions?