Notch on Harmonic Balancer Doesn't line up with Tab at TDC

Performance mods and Advanced Stroker discussion.
Post Reply
JeepJerk
Posts: 3
Joined: June 27th, 2019, 7:52 am
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: TJ

Notch on Harmonic Balancer Doesn't line up with Tab at TDC

Post by JeepJerk »

So I've got everything together but am confused as to why the notch on my harmonic balancer doesn't line up with the tab on the timing cover at TDC. With #1 at TDC the notch is at about 2 o'clock if you consider the tab at 0 degrees to be 12 o'clock. What's up with that? I understand this won't be used for timing but it seems like something is wrong.
User avatar
Cheromaniac
I live here
I live here
Posts: 3180
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus
Contact:

Re: Notch on Harmonic Balancer Doesn't line up with Tab at TDC

Post by Cheromaniac »

Unless your harmonic balancer is new, it's possible the outer ring might have slipped on the rubber sandwich that bonds it to the inner part. You might need to buy a new harmonic balancer.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
Bertismyname
I think I'll order a "tab"
I think I'll order a "tab"
Posts: 41
Joined: May 12th, 2020, 8:01 pm
Vehicle Year: 1999
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Notch on Harmonic Balancer Doesn't line up with Tab at TDC

Post by Bertismyname »

is the engine on the stand? Last engine I built i found mine to be off when I was degreeing my cam. I then added an adjustable pointer. That was on a big block ford. I would think that a timing tape or adding a new mark will work. But that basically requires verification of timing components and finding actual top dead center.
I've also seen brand new balancers have incorrect marks. So....
JeepJerk
Posts: 3
Joined: June 27th, 2019, 7:52 am
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: TJ

Re: Notch on Harmonic Balancer Doesn't line up with Tab at TDC

Post by JeepJerk »

So it's a new balancer- what I found when I got around to looking at the 4.2 timing cover is that the timing marks are about 40 degrees 'after' the marks on the 4.0 cover. So, the woodruff key groove on the early 4.2 crank (mine is from the early '70s) is in a different place than the one on the 4.0 crank that was in this engine. I only realized this once the engine was in the Jeep so I had to screw around with it to get the distributor set, otherwise I could've made a mark and it would've been much easier (and less alarming) for me. Anyhow, good to know in advance!
Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests