crankshaft tdc timing problem

vi_ryder · Post by **vi_ryder** » Wed Dec 09, 2009 9:20 pm

i finally got the timing belt on today since it was warm. but i think i made a big mistake. when setting crankshaft to TDC i rotated it counter clockwise a couple times cause i had to set to 3 notches before tdc. and when i moved it back to tdc with wrench after setting the tensioner, its not as stiff or hard as it once was. when i removed the pulley bolt after using it turn the crankshaft to tdc the crankshaft keep moving from tdc. so my question is after i put the timing cover on then put harmonic balancer pulley on how do i stop the crankshaft from moving from tdc? whats the worst that could happen from turn the crankshaft backward and foward couple times?

ZeroChad · Post by **ZeroChad** » Wed Dec 09, 2009 10:42 pm

You should really only rotate the crankshaft clockwise. Did you make sure that the camshaft pulley was aligned at DTC while the crank sprocket was? Why do you need to keep it at DTC while installing the balancer?

When I do this, I make sure that the rockers are unbolted so that there is no chance of valve hitting.

vi_ryder · Post by **vi_ryder** » Wed Dec 09, 2009 10:51 pm

yea the camshaft is at dtc but i have it torqued down. should i release the rockers but i made a mistake and over torqued the rocker arm bolt #1 so its not tighten so im kinda spectacle but removing that one bolt. so what should i do? so does it make a difference if the crankshaft moves when tighten the balancer pulley down? kinda confusing.

Broken Glass · Post by **Broken Glass** » Wed Dec 09, 2009 10:56 pm

if i understand your problem correctly, yes it does. IIRC the cam and crank should be at TDC after its tightened, so if it rotates you would have to compensate for that. someone who knows more please correct me if im wrong

ZeroChad · Post by **ZeroChad** » Fri Dec 11, 2009 5:16 pm

Broken Glass wrote:if i understand your problem correctly, yes it does. IIRC the cam and crank should be at TDC after its tightened, so if it rotates you would have to compensate for that. someone who knows more please correct me if im wrong

Thats right.

If you've stripped one of the rocker bolts your'e gunna wanna get it out using a bolt extractor or otherwise.

Broken Glass · Post by **Broken Glass** » Fri Dec 11, 2009 6:39 pm

I think he means the threads in the head are stripped, so the bolts just spinning. not sure tho

vi_ryder · Post by **vi_ryder** » Fri Dec 11, 2009 8:01 pm

So should i loosen the rocker arms to set timing marks to TDC even if one of the bolts is stripped? also when i tightened the tensioner the first time it was real tight but i found out the crank was not at TDC. So i proceeded to loosen the tensioner and set the crank at tdc but the belt was not as tight and is kinda slack. so how do i get rid of the slack?

Post by **occasional demons** » Fri Dec 11, 2009 9:50 pm

If the rocker shaft bolt hole is stripped, you will need to repair the threads with a heli coil kit. Otherwise the rocker shaft will fail due to the lack of support where that bolt is. If you don't have a torque wrench, I would get even a cheap one to torque these down.

Do you have a hyd tensioner or the Litens style?
http://chronoscender.freeservers.com/ne ... gbelt.html

chronoscender wrote:because after you remove the timing belt you must make absolutely certain that neither the crankshaft or camshaft is allowed to move more than a couple degrees or you could damage the valvetrain.

^^^
Loosening the rocker shafts is the best way to ensure not damaging the valves when loosening/torquing the cam bolt. I recommend a pair of chain style visegrips to hold the cam sproket while removing/instaling the cam bolt.

Also remove the spark plugs, so the engine turns freely. You want to turn it at least two full clockwise crank revolutions after setting the marks, to ensure they are still in place.

Edit: this is where you are lining up the marks, correct?
The tensioner pictured is the Litens type.

vi_ryder · Post by **vi_ryder** » Mon Dec 14, 2009 11:55 am

I have a litens tensioner and I all ready torqued the cam gear bolt after the rocker arm bolt stripped in head. But i tightened It in place but I over torque it so I keep spinning but it is not loosely. It has a lil bit of tension on it so I turned it until it felt real tight. Is there any way around setting the timing and removing the slack off the belt without removing or loosen the rocker arms.?

Post by **occasional demons** » Mon Dec 14, 2009 12:30 pm

The forces on that shaft bolt are going to pull it up out of the head. It is only a matter of time. You can either do it now, or wait till it fails. Now is cheaper/easier. It will only take an hour or two at the most to remove the rocker shaft, drill out the hole rethread it to the helicoil threads and install the insert.

Just because it catches and holds doesn't mean it will last. If it just keeps spinning, it is done.

List price for a rocker shaft $42.30
an intake rocker $38.45
an exhaust rocker $62.70

This is whats at stake, in addition to the head itself if the bolt hole is stretched from everything thrashing around in there.

This is your primary concern, getting the timing marks set is not the biggest issue at the moment.

Haganracing · Post by **Haganracing** » Wed Dec 16, 2009 12:46 am

Broken Glass wrote:if i understand your problem correctly, yes it does. IIRC the cam and crank should be at TDC after its tightened, so if it rotates you would have to compensate for that. someone who knows more please correct me if im wrong

+1

Once you tighten the belt, it should both be aligned with the arrow and notches

Once you get that all done, i'd turn the crankshaft manually about 6 full times to make sure its going to be good and nothing hits.

Broken Glass · Post by **Broken Glass** » Wed Dec 16, 2009 9:30 pm