With #1 spark plug removed, turn the engine over clockwise using the 3/4″ front crankshaft bolt.
You will see the degree marks on your front cover and you will see the timing mark on the balancer. Mark them with chalk or white-out.
While turning the engine over, put your finger/thumb over #1 spark plug hole. As the mark on the balancer approaches the marks on the front cover, if you are coming up on #1 TDC, pressure in the cylinder will push on your finger. If there’s no pressure, you’re at #6 TDC and need to crank the engine over until you see the marks coming together and you get pressure. Set the mark on the balancer to the 0 mark on the front cover.
Revised 1-31-2016
Another good way to find T D C, thanks!
whats tdc???
Top Dead Center, when the piston is all the way up on compression or exhaust stroke.
/ok
So, what if your block has a different indicator scale on it?
Mine is similar, but has a … tube about where your 0 (zero) is.
Well I hope that tube/ hole is close enough to where the Zero is supposed to be.
It will also have marks on it. Those are what you use. The hole was for a timing probe that wasn’t used for very long.
ok, Thank you very much!
What if I’m getting pressure and the mark on the balancer isnt visible?
The outer ring of your balancer may have become delaminated.
Is it really necessary to feel for pressure on cyl #1?
I mean if you are looking at the rotor and it is pointing to the #1 terminal on the distributor and the timing mark is at 0 deg, isn’t that always TDC for cyl #1?
Otherwise the rotor would be 180 deg out and pointing to the #6 terminal on the distributor when the timing mark is at 0 deg.
I was beginning to set my 89 cherokee 6 cyl. TDC as shown. Short history, I had 4 months prior replaced my rotor and cap. But after running my jeep for another 800 miles one day it would not start. I checked several things fuel pressure, grounds, CPS and spark of which I was showing some small spark, But still wouldn’t start. At the onset of TDC check, I began by pulling the distributor cap. What I found next was the plastic rotor had broke in 3 pieces. Wow, just amazing since I had recently replaced the cap and rotor. If jeep isn’t running, check this first as the rotor part that I had purchased was cheaply made. I went to auto parts and replaced. First turn jeep started. Might be wise to carry and extra rotor.
Okay…..
Hi Cruiser
I am in the middle of a cam/lifter replacement. I had pulled the head before setting TDC but didnt think much of it as i still had the harmonic balancer and distributor in. So i set it to 0 at the timing marks on the timing cover and the rotor was pointing in the neighborhood of the #1 plug wire and the #1 piston was at the top of the stroke. I thought i was all good until i pulled the timing cover off and the cam and crank gear marks were 180 out in reference to the distributor. Are these supposed to be aligned at TDC? i lined them up to install the new cam but now unsure if i should install the distributor like it was or if i should index it and have it pointing at #1 with the gear marks aligned as well. It didnt run great before but it also had two wiped lobes. I have read these motors will still run with everything 180 out but not sure how accurate that is. Help!! thanks!
Get the cam done correctly first. If you’re on #1 TDC, both valves will be closed.