I have a 1985 ford f250 with a 300 bored .60 over and the timing marks on the harmonic balancer do not relate to TDC on the number 1 cylinder. The marks are aligned with TDC on number 5. How can this be?  

Balancer has sheared the woodruff key and has spun on the crankshaft? 

Is that the stock balancer that came with the engine? I can't remember, but I think SBF balancers will fit on the big 6 engines. Does TDC on #5 sit exactly at 0 on the timing marks? Has the outer ring separated from the rubber and rotated?

 

Josh

Is that the stock balancer that came with the engine? I can't remember, but I think SBF balancers will fit on the big 6 engines. Does TDC on #5 sit exactly at 0 on the timing marks? Has the outer ring separated from the rubber and rotated?

 

Josh

yes, TDC goes to the #5 cylinder

the key is still good, the engine ran great before the computer went out

"the timing marks on the harmonic balancer do not relate to TDC on the number 1 cylinder"

 

I'm confused. Are you saying that when you bring #1 cylinder up to TDC, the pointer doesn't point at 0 degrees? 

 

The firing order is 142 536. Seems to me the only problem is the plug wires are 180 degrees off. I would retime the engine by bringing #1 up to TDC. The timing marks on the balancer should be at 0. Then reinstall the plug wires. 

 

Edit from another forum:

 

 

Ford in there infant wisdom saw fit to put 2 different sets on many of the 4.9s. on mine there is one set on the timing gear cover. dont use this one if you have the other one it is located on the other side or passenger side. it is a metal strip that has notches in it. one big notch which is TDC and smaller notches going both ways out from TDC . there are also 2 different marks on the crank pulley. one square notch that is easy to see. dont use this one. the other correct one is a very small line scribed in the pulley and very hard to see if the pulley is dirty. this is the one to use. 

Edited November 18, 201411 yr by john in KY

How sure are you that it is the correct balancer?

And look for clues that the outer ring may have spun. Look for a lot of cracks, missing pieces, or bulges on the rubber isolator.

If all else fails, dont worry about it. I time my engines with my spidey senses, and if i use a timing light, its for curiosity sake or for documentation.

With the number one piston on TDC with valves closed. Either mark is about 45degrees off from either side timing references. If you rotate the thin line mark scribed on the balancer then it is number 5 cylinder on TDC.