Can't get my cam sproket back on, what I'm I doing wrong!?

[Guest iskone]

Peice of crap cam sprocket!!! I get my head back and can't get the sprocket back on. The nub on the front of the cam is almost dead center on top and no matter wht I try I can't get it on. It should go back on the number 2 hole.

 

I tried retarding the cam so I could use the number one hole but when I put the sprocket on I can only turn thr motor a little bit in each direction. I used a socket wrenh and tuned it with the crank nut to check for clearance.

 

If I turn the cam forward so the nub is faced down and then turn the motor 90* forward that shoud all match up, right? I would do it this way to gain enough slack with the chain that I could fit the sprocket over the nub when it is at the bottom.

 

There must be an easier way!!!

 

Isk

[Chemicalblue]

Ck the tentioner and make sure it hasent poped out this is usally the prob. Use a long flat screwdriver to get it back in , unless its out beyond putting it back in that way. U may need to take off the front cover (suc). Ive used a magnet before to get it lined back up, just as long as the spring hasent poped out too. Good Luck

[Guest DoTheDrew888]

The engine may be turning only a little bit because the engine and cam are not in sync. Make sure the engine is at TDC and the cam is also at TDC. If they are not matched up then your pistons are contacting valves and that is what makes it so that you cannot turn it. A suggestion for getting the sprocket on is to wrap the end of a screw driver in electrical tape and stick it in the thread hole in the front of the cam. The tape it to protect the threads on the inside of the cam. You can use it to leverage the sprocket into place.

[COZY Z COLE]

See if this helps.......Scroll down to Cam Chain Tensioner...

 

http://www.geocities.com/zgarage2001/rebuild.html

 

LARRY

[schwiplarkin]

i have had the same problem,, if it is just slightly off loosen the cam tower bolts and use a rubber mallet to tap the cam towards the back of the motor , this will give you alittle more room to play with,, once the sprocket is on use the cam bolt to pull it back into place,, make sure you retighten and torque the cam tower bolts, hope this helps

[Guest iskone]

THnaks for all the help!!

I'll work on it more when I get off work. I tried the tensioner but I had no luck. I'll go through all the methods mentioned till something works.

 

As far as the motor and cam both at TDC. I think The cam is retarded just a bit right now and the valves are contacting the psitons. My turn the cam 180 and turn the crank 90 is a last resort.

Isk

[Lockjaw]

You should loosen the cam towers and tap them with a mallet and tighten until the cam turns. I presume the rocker arms are not on the head right?

 

Then position the sprocket, insert the bolt, and slowly tighten it, and if you have the dowel pin and the hole in the sprocket lined up, and haven't popped the tensioner, it should go right on.

[Guest DoTheDrew888]

You have to make sure everything is at TDC when you put it all together! If you try to start it and things are out of wack then you are going to really have some problems. Save yourself a big headache later on and triple check everything while its still apart.

[Guest iskone]

TDC is not a problem. When I was trying to put it back on everything was TDC.

 

I'm gonna try to loosen the cam tower bolts ands slide the cam back a little to gain enough clearance to fit the dowl in the sprocket. I was SOOOOOO close yesterday that sliding the cam back should do it.

 

Isk

[JMortensen]

Make sure the chain guides are pushed back. Usually on a motor like yours the chain guide holes are slotted. Loosen the 2 10mm bolts on the right side and pull the chain tensioner away from the chain. Attach the cam sprocket, then slide the tensioner up to the chain. How much tension to put on the chain guide is an open question for me. I don't put much pressure on the guide at all, but I do try to move the top and bottom so that the chain hits the top and bottom of the curved guide tangentially.

[Guest iskone]

When you say "push back the chain guides" Do you mean at the top where the bolts are? At the top it is already pushed back as far as it can go. I hope you don't mean at the top and bottom of the chain guide, because that's what it sounds like. I'm trying to avoid removing the crank pulley, water pump, etc...

 

 

If I do have to remove the chain cover will a universal crank pulley puller work on the Z pulley?

 

Isk

[Guest DoTheDrew888]

You can use one but be very careful. I broke a pulley just the other day using one of those things. I found that it is easier to just use a plastic or rubber mallet and tap around the edge of the pulley until it comes loose.

[Xander]

I don't know if this is going to help but i recently had to reinstall my head 4 times because of head gasket problems.

 

When removing the head first put the crank in TDC. You did that right?

I used a wooden wedge rammed down between the chain to keep the chain and fixed and to keep the tensioner from falling out.

 

then this is the way I put it all back together again.

 

torque down the head.

Put sprocket back on cam and tighten the sprocket bolt hand tight. The sprocket is now crooked on the camshaft.

Remove the wooden wedge.

the chain tensioner will now pull the chain tight.

I now use a big screwdriver and lever the sprocket into place. I just put the screwdriver thru a hole in the sprocket and the tip on a cam tower. This way I lever the sprocket upwards and voila it is on. At least thats how I did it 4 times now.

This will also make it possible to slighty rotate the camshaft to line everything up properly.

 

Hope this helps.

 

I'm sorry if my english is a bit lousy but these things are hard to explain in words.

[Pyro]

If you didn't wedge the chain before taking off the cam gear then the tensioner sprung out. Start removing the timing chain cover if you what to get the chain back on.

 

If you did use a wedge on the chain then use the big cam bolt to pull the gear onto the cam.

[Cody 82 ZXT]

Hate to say it but, it sounds like the tensioner has gotten the best of you. It happened to me several years ago.

[Guest iskone]

ARGGGHHHHHHHHHH

 

Oliver at Z specialties (Just rebuilt head) was telling me not to loosen the cam tower bolts. Everything is pointing the tensioner.

 

I'm just gonna take off the timing cover It's my own fault so I guess it's time to stop looking for the easy way out. What pisses me off is I did all the stuff I thought I was suppose to.

 

Anyone know where I can get a new pulley for cheap in case I break mine?

 

Isk

[technicalninja]

You should be able to see the tensioner with a flashlight. if you can see a spring it has come out to far. will need to remove front cover to fix. I have "fished" a tensioner back into its hole with couple of long thin screwdrivers and a long mechanical fingers but it took some luck.

As for loosening cam tower bolts- DON'T. Cam towers should only be tightened up with all rocker arms removed and chain off. although the towers have guide pins they will not tighten up correctly with any external loads on the cam. On bench I tighten all bolts just past finger tight starting with middle set. Then try to rotate cam by hand. Adjust cam tower position with small hammer as I slowly tighten up bolts in stages. You would be suprised at how much drag you can eliminate using this procedure. Just tighten up all bolts one time with out aliging and the cam can be difficult to turn by hand. Do it the way I suggest and the cam will feel like it is on roller bearings. I also recheck cam turning torque after I torque the head bolts as some go through the cam towers and re-adjust if needed. The hammer is used very lightly to "vibrate" the cam towers into alignment.

 

Don't believe me- next time you have a head fully apart just stick the towers on the guide pins (no bolts) and wiggle back and forth- more play there than you thought.

My 78 Nissan SM has a caution statement on page EM-7 "Never remove camshaft bearing unless you have a suitable machine for boring camshaft bearing in line. If you once remove camshaft bearings, bearing centers will come out of alignment; reconditioning is very difficult with out center borings" The SM does not list where you might get a cam with bigger bearing journals (never been available IMO). My 82 SM says it a little different " Do not remove camshaft brackets. If camshaft bracket were removed, install them by checking for a smooth rotation with the camshaft."

I would not loosen the cam towers for any reason after aligning them on the bench.

Normally after the tensioner has come fully out to much play exists in the chain and the gears will slip on no problem. Just before the tensioner pops out it usually cocks up slightly and binds in the housing. If your tensioner has done this you will have to apply pressure against the face of tensioner with one screw driver (or long very thin prybar) and at same time push down on top of tensioner foot with another long thin screwdriver. When the angles are right the tensioner will slide back in.

Look closley at what you have at the tensioner right now.

I have been lucky at getting them back in. Patients and "holding your mouth right" will pay off.

Good luck

[Cody 82 ZXT]

I've heard of several guys getting the tensioner back in using the above mentioned method. Looks like the " holding your mouth right" part of the post may be the key to the hole thing. Any other luck charms would be good also.

[Wide260z]

I had that problem when replacing a head gasket. I did the same thing, i had to take the cover off and the crank pully. I didn't damage mine at all using a puller. I realized the tentioner was out and just twisted my leg opened my mouth, crossed my fingers and prayed it would stay.

[Cody 82 ZXT]

If you have to pull the cover off take the time to make yourself a tensioner stop for the next time you need it. Thats what I did and it has come in handy several times in the last few years.