Aloha everyone, just wanted to follow up after another successful timing rebuild on the 4.0l sohc with some information I found that might be useful.

After assembly and testing, I had a p0320 code for crank signal interference and the engine was running rough. After a long couple weeks of diagnostics and reaching out to a fellow mechanic who was also working on a 4.0 timing job, we came to the conclusion that there is a compatibility issue with the new Ford harmonic balancer that uses the pressed on tone ring.

So his issue was from the Cloyes timing kit. The crankshaft front timing sprocket is 0.003" thinner than the Ford sprockets and causes the harmonic balancer to seat .003 closer to the engine and therefore the narrow tone ring on the balancer was missing the sensor location enough to mess with the readings. He put a puller on the tone ring and moved it slightly further out and boom, engine started and ran. He replaced the balancer with a Dorman that had the old style tone wheel cut into the balancer iron case and problem solved.

My issue was similar, I spun the tone ring by about .007" with the timing tools. I think this happened because I had the timing tool attached to the balancer while tightening the jackshaft bolts. Replaced with Dorman balancer a after a long electrical diagnosis showing all wiring and sensors were good. Problem solved.

I would suggest anyone working on these engines avoid the new Ford harmonic balancers with the tin metal tone rings.

 

Ask for the "old style" HB?
Isn't the rubber all that fails?
Harmonic balancers are rebuildable, no? Obviously not if the economics don't work.

 

From what I saw on rockauto the Dorman new balancers are the old style. Looks like they are collecting cores, rebuilding them with new rubber and a paint coat and sending them out. I think for the cost, less than $100, it's easier to just pick one up. I don't think a diyer could repair the rubber damper successfully.

 

When I did the cam timing chain rebuild, I could see the new OEM sprocket on the crankshaft I caused a misalignment to the jackshaft. I just used the original sprocket. It showed no signs of wear and has been working fine for nearly 50K miles since the rebuild. I reused the original harmonic balancer too.